Squashed 'bin/dash/' content from commit a45870f

git-subtree-dir: bin/dash
git-subtree-split: a45870f71f42be6bf3c8eada04debd1008f9dc3e

78 files changed, 23685 insertions, 0 deletions

diff --git a/src/.gitignore b/src/.gitignore
new file mode 100644
index 00000000..644eccb8
--- /dev/null
+++ b/src/.gitignore
@@ -0,0 +1,13 @@
+*.o
+builtins.[ch]
+builtins.def
+dash
+init.c
+mkinit
+mknodes
+mksignames
+mksyntax
+nodes.[ch]
+signames.c
+syntax.[ch]
+token.h
diff --git a/src/Makefile.am b/src/Makefile.am
new file mode 100644
index 00000000..17324653
--- /dev/null
+++ b/src/Makefile.am
@@ -0,0 +1,70 @@
+AM_YFLAGS = -d
+
+COMMON_CFLAGS = -Wall
+COMMON_CPPFLAGS = \
+	-DBSD=1 -DSHELL
+
+AM_CFLAGS = $(COMMON_CFLAGS)
+AM_CPPFLAGS = -include $(top_builddir)/config.h $(COMMON_CPPFLAGS)
+AM_CFLAGS_FOR_BUILD = -g -O2 $(COMMON_CFLAGS) 
+AM_CPPFLAGS_FOR_BUILD = $(COMMON_CPPFLAGS)
+
+COMPILE_FOR_BUILD = \
+	$(CC_FOR_BUILD) $(DEFAULT_INCLUDES) $(AM_CPPFLAGS_FOR_BUILD) \
+	$(CPPFLAGS_FOR_BUILD) \
+	$(AM_CFLAGS_FOR_BUILD) $(CFLAGS_FOR_BUILD) 
+
+bin_PROGRAMS = dash
+
+dash_CFILES = \
+	alias.c arith_yacc.c arith_yylex.c cd.c error.c eval.c exec.c expand.c \
+	histedit.c input.c jobs.c mail.c main.c memalloc.c miscbltin.c \
+	mystring.c options.c parser.c redir.c show.c trap.c output.c \
+	bltin/printf.c system.c bltin/test.c bltin/times.c var.c
+dash_SOURCES = \
+	$(dash_CFILES) \
+	alias.h arith_yacc.h bltin/bltin.h cd.h error.h eval.h exec.h \
+	expand.h \
+	init.h input.h jobs.h machdep.h mail.h main.h memalloc.h miscbltin.h \
+	myhistedit.h mystring.h options.h output.h parser.h redir.h shell.h \
+	show.h system.h trap.h var.h
+dash_LDADD = builtins.o init.o nodes.o signames.o syntax.o
+
+HELPERS = mkinit mksyntax mknodes mksignames
+
+BUILT_SOURCES = builtins.h nodes.h syntax.h token.h token_vars.h
+CLEANFILES = \
+	$(BUILT_SOURCES) $(patsubst %.o,%.c,$(dash_LDADD)) \
+	$(HELPERS) builtins.def
+
+man_MANS = dash.1
+EXTRA_DIST = \
+	$(man_MANS) \
+	mktokens mkbuiltins builtins.def.in mkinit.c \
+	mknodes.c nodetypes nodes.c.pat mksyntax.c mksignames.c
+
+token.h token_vars.h: mktokens
+	$(AM_V_GEN)$(SHELL) $^
+
+builtins.def: builtins.def.in $(top_builddir)/config.h
+	$(AM_V_CC)$(COMPILE) -E -x c -o $@ $<
+
+builtins.c builtins.h: mkbuiltins builtins.def
+	$(AM_V_GEN)$(SHELL) $^
+
+init.c: mkinit $(dash_CFILES)
+	$(AM_V_GEN)./$^
+
+nodes.c nodes.h: mknodes nodetypes nodes.c.pat
+	$(AM_V_GEN)./$^
+
+syntax.c syntax.h: mksyntax
+	$(AM_V_GEN)./$^
+
+signames.c: mksignames
+	$(AM_V_GEN)./$^
+
+mksyntax: token.h
+
+$(HELPERS): %: %.c
+	$(AM_V_CC)$(COMPILE_FOR_BUILD) -o $@ $<
diff --git a/src/TOUR b/src/TOUR
new file mode 100644
index 00000000..e30836e1
--- /dev/null
+++ b/src/TOUR
@@ -0,0 +1,343 @@
+#	@(#)TOUR	8.1 (Berkeley) 5/31/93
+
+NOTE -- This is the original TOUR paper distributed with ash and
+does not represent the current state of the shell.  It is provided anyway
+since it provides helpful information for how the shell is structured,
+but be warned that things have changed -- the current shell is
+still under development.
+
+================================================================
+
+                       A Tour through Ash
+
+               Copyright 1989 by Kenneth Almquist.
+
+
+DIRECTORIES:  The subdirectory bltin contains commands which can
+be compiled stand-alone.  The rest of the source is in the main
+ash directory.
+
+SOURCE CODE GENERATORS:  Files whose names begin with "mk" are
+programs that generate source code.  A complete list of these
+programs is:
+
+        program         intput files        generates
+        -------         ------------        ---------
+        mkbuiltins      builtins            builtins.h builtins.c
+        mkinit          *.c                 init.c
+        mknodes         nodetypes           nodes.h nodes.c
+        mksignames          -               signames.h signames.c
+        mksyntax            -               syntax.h syntax.c
+        mktokens            -               token.h
+        bltin/mkexpr    unary_op binary_op  operators.h operators.c
+
+There are undoubtedly too many of these.  Mkinit searches all the
+C source files for entries looking like:
+
+        INIT {
+              x = 1;    /* executed during initialization */
+        }
+
+        RESET {
+              x = 2;    /* executed when the shell does a longjmp
+                           back to the main command loop */
+        }
+
+It pulls this code out into routines which are when particular
+events occur.  The intent is to improve modularity by isolating
+the information about which modules need to be explicitly
+initialized/reset within the modules themselves.
+
+Mkinit recognizes several constructs for placing declarations in
+the init.c file.
+        INCLUDE "file.h"
+includes a file.  The storage class MKINIT makes a declaration
+available in the init.c file, for example:
+        MKINIT int funcnest;    /* depth of function calls */
+MKINIT alone on a line introduces a structure or union declara-
+tion:
+        MKINIT
+        struct redirtab {
+              short renamed[10];
+        };
+Preprocessor #define statements are copied to init.c without any
+special action to request this.
+
+INDENTATION:  The ash source is indented in multiples of six
+spaces.  The only study that I have heard of on the subject con-
+cluded that the optimal amount to indent is in the range of four
+to six spaces.  I use six spaces since it is not too big a jump
+from the widely used eight spaces.  If you really hate six space
+indentation, use the adjind (source included) program to change
+it to something else.
+
+EXCEPTIONS:  Code for dealing with exceptions appears in
+exceptions.c.  The C language doesn't include exception handling,
+so I implement it using setjmp and longjmp.  The global variable
+exception contains the type of exception.  EXERROR is raised by
+calling error.  EXINT is an interrupt.
+
+INTERRUPTS:  In an interactive shell, an interrupt will cause an
+EXINT exception to return to the main command loop.  (Exception:
+EXINT is not raised if the user traps interrupts using the trap
+command.)  The INTOFF and INTON macros (defined in exception.h)
+provide uninterruptable critical sections.  Between the execution
+of INTOFF and the execution of INTON, interrupt signals will be
+held for later delivery.  INTOFF and INTON can be nested.
+
+MEMALLOC.C:  Memalloc.c defines versions of malloc and realloc
+which call error when there is no memory left.  It also defines a
+stack oriented memory allocation scheme.  Allocating off a stack
+is probably more efficient than allocation using malloc, but the
+big advantage is that when an exception occurs all we have to do
+to free up the memory in use at the time of the exception is to
+restore the stack pointer.  The stack is implemented using a
+linked list of blocks.
+
+STPUTC:  If the stack were contiguous, it would be easy to store
+strings on the stack without knowing in advance how long the
+string was going to be:
+        p = stackptr;
+        *p++ = c;       /* repeated as many times as needed */
+        stackptr = p;
+The following three macros (defined in memalloc.h) perform these
+operations, but grow the stack if you run off the end:
+        STARTSTACKSTR(p);
+        STPUTC(c, p);   /* repeated as many times as needed */
+        grabstackstr(p);
+
+We now start a top-down look at the code:
+
+MAIN.C:  The main routine performs some initialization, executes
+the user's profile if necessary, and calls cmdloop.  Cmdloop is
+repeatedly parses and executes commands.
+
+OPTIONS.C:  This file contains the option processing code.  It is
+called from main to parse the shell arguments when the shell is
+invoked, and it also contains the set builtin.  The -i and -j op-
+tions (the latter turns on job control) require changes in signal
+handling.  The routines setjobctl (in jobs.c) and setinteractive
+(in trap.c) are called to handle changes to these options.
+
+PARSING:  The parser code is all in parser.c.  A recursive des-
+cent parser is used.  Syntax tables (generated by mksyntax) are
+used to classify characters during lexical analysis.  There are
+three tables:  one for normal use, one for use when inside single
+quotes, and one for use when inside double quotes.  The tables
+are machine dependent because they are indexed by character vari-
+ables and the range of a char varies from machine to machine.
+
+PARSE OUTPUT:  The output of the parser consists of a tree of
+nodes.  The various types of nodes are defined in the file node-
+types.
+
+Nodes of type NARG are used to represent both words and the con-
+tents of here documents.  An early version of ash kept the con-
+tents of here documents in temporary files, but keeping here do-
+cuments in memory typically results in significantly better per-
+formance.  It would have been nice to make it an option to use
+temporary files for here documents, for the benefit of small
+machines, but the code to keep track of when to delete the tem-
+porary files was complex and I never fixed all the bugs in it.
+(AT&T has been maintaining the Bourne shell for more than ten
+years, and to the best of my knowledge they still haven't gotten
+it to handle temporary files correctly in obscure cases.)
+
+The text field of a NARG structure points to the text of the
+word.  The text consists of ordinary characters and a number of
+special codes defined in parser.h.  The special codes are:
+
+        CTLVAR              Variable substitution
+        CTLENDVAR           End of variable substitution
+        CTLBACKQ            Command substitution
+        CTLESC              Escape next character
+
+A variable substitution contains the following elements:
+
+        CTLVAR type name '=' [ alternative-text CTLENDVAR ]
+
+The type field is a single character specifying the type of sub-
+stitution.  The possible types are:
+
+        VSNORMAL            $var
+        VSMINUS             ${var-text}
+        VSMINUS|VSNUL       ${var:-text}
+        VSPLUS              ${var+text}
+        VSPLUS|VSNUL        ${var:+text}
+        VSQUESTION          ${var?text}
+        VSQUESTION|VSNUL    ${var:?text}
+        VSASSIGN            ${var=text}
+        VSASSIGN|VSNUL      ${var=text}
+
+The name of the variable comes next, terminated by an equals
+sign.  If the type is not VSNORMAL, then the text field in the
+substitution follows, terminated by a CTLENDVAR byte.
+
+Commands in back quotes are parsed and stored in a linked list.
+The locations of these commands in the string are indicated by
+the CTLBACKQ character.
+
+The character CTLESC escapes the next character, so that in case
+any of the CTL characters mentioned above appear in the input,
+they can be passed through transparently.  CTLESC is also used to
+escape '*', '?', '[', and '!' characters which were quoted by the
+user and thus should not be used for file name generation.
+
+CTLESC characters have proved to be particularly tricky to get
+right.  In the case of here documents which are not subject to
+variable and command substitution, the parser doesn't insert any
+CTLESC characters to begin with (so the contents of the text
+field can be written without any processing).  Other here docu-
+ments, and words which are not subject to splitting and file name
+generation, have the CTLESC characters removed during the vari-
+able and command substitution phase.  Words which are subject
+splitting and file name generation have the CTLESC characters re-
+moved as part of the file name phase.
+
+EXECUTION:  Command execution is handled by the following files:
+        eval.c     The top level routines.
+        redir.c    Code to handle redirection of input and output.
+        jobs.c     Code to handle forking, waiting, and job control.
+        exec.c     Code to path searches and the actual exec sys call.
+        expand.c   Code to evaluate arguments.
+        var.c      Maintains the variable symbol table.  Called from expand.c.
+
+EVAL.C:  Evaltree recursively executes a parse tree.  The exit
+status is returned in the global variable exitstatus.  The alter-
+native entry evalbackcmd is called to evaluate commands in back
+quotes.  It saves the result in memory if the command is a buil-
+tin; otherwise it forks off a child to execute the command and
+connects the standard output of the child to a pipe.
+
+JOBS.C:  To create a process, you call makejob to return a job
+structure, and then call forkshell (passing the job structure as
+an argument) to create the process.  Waitforjob waits for a job
+to complete.  These routines take care of process groups if job
+control is defined.
+
+REDIR.C:  Ash allows file descriptors to be redirected and then
+restored without forking off a child process.  This is accom-
+plished by duplicating the original file descriptors.  The redir-
+tab structure records where the file descriptors have be dupli-
+cated to.
+
+EXEC.C:  The routine find_command locates a command, and enters
+the command in the hash table if it is not already there.  The
+third argument specifies whether it is to print an error message
+if the command is not found.  (When a pipeline is set up,
+find_command is called for all the commands in the pipeline be-
+fore any forking is done, so to get the commands into the hash
+table of the parent process.  But to make command hashing as
+transparent as possible, we silently ignore errors at that point
+and only print error messages if the command cannot be found
+later.)
+
+The routine shellexec is the interface to the exec system call.
+
+EXPAND.C:  Arguments are processed in three passes.  The first
+(performed by the routine argstr) performs variable and command
+substitution.  The second (ifsbreakup) performs word splitting
+and the third (expandmeta) performs file name generation.  If the
+"/u" directory is simulated, then when "/u/username" is replaced
+by the user's home directory, the flag "didudir" is set.  This
+tells the cd command that it should print out the directory name,
+just as it would if the "/u" directory were implemented using
+symbolic links.
+
+VAR.C:  Variables are stored in a hash table.  Probably we should
+switch to extensible hashing.  The variable name is stored in the
+same string as the value (using the format "name=value") so that
+no string copying is needed to create the environment of a com-
+mand.  Variables which the shell references internally are preal-
+located so that the shell can reference the values of these vari-
+ables without doing a lookup.
+
+When a program is run, the code in eval.c sticks any environment
+variables which precede the command (as in "PATH=xxx command") in
+the variable table as the simplest way to strip duplicates, and
+then calls "environment" to get the value of the environment.
+There are two consequences of this.  First, if an assignment to
+PATH precedes the command, the value of PATH before the assign-
+ment must be remembered and passed to shellexec.  Second, if the
+program turns out to be a shell procedure, the strings from the
+environment variables which preceded the command must be pulled
+out of the table and replaced with strings obtained from malloc,
+since the former will automatically be freed when the stack (see
+the entry on memalloc.c) is emptied.
+
+BUILTIN COMMANDS:  The procedures for handling these are scat-
+tered throughout the code, depending on which location appears
+most appropriate.  They can be recognized because their names al-
+ways end in "cmd".  The mapping from names to procedures is
+specified in the file builtins, which is processed by the mkbuil-
+tins command.
+
+A builtin command is invoked with argc and argv set up like a
+normal program.  A builtin command is allowed to overwrite its
+arguments.  Builtin routines can call nextopt to do option pars-
+ing.  This is kind of like getopt, but you don't pass argc and
+argv to it.  Builtin routines can also call error.  This routine
+normally terminates the shell (or returns to the main command
+loop if the shell is interactive), but when called from a builtin
+command it causes the builtin command to terminate with an exit
+status of 2.
+
+The directory bltins contains commands which can be compiled in-
+dependently but can also be built into the shell for efficiency
+reasons.  The makefile in this directory compiles these programs
+in the normal fashion (so that they can be run regardless of
+whether the invoker is ash), but also creates a library named
+bltinlib.a which can be linked with ash.  The header file bltin.h
+takes care of most of the differences between the ash and the
+stand-alone environment.  The user should call the main routine
+"main", and #define main to be the name of the routine to use
+when the program is linked into ash.  This #define should appear
+before bltin.h is included; bltin.h will #undef main if the pro-
+gram is to be compiled stand-alone.
+
+CD.C:  This file defines the cd and pwd builtins.  The pwd com-
+mand runs /bin/pwd the first time it is invoked (unless the user
+has already done a cd to an absolute pathname), but then
+remembers the current directory and updates it when the cd com-
+mand is run, so subsequent pwd commands run very fast.  The main
+complication in the cd command is in the docd command, which
+resolves symbolic links into actual names and informs the user
+where the user ended up if he crossed a symbolic link.
+
+SIGNALS:  Trap.c implements the trap command.  The routine set-
+signal figures out what action should be taken when a signal is
+received and invokes the signal system call to set the signal ac-
+tion appropriately.  When a signal that a user has set a trap for
+is caught, the routine "onsig" sets a flag.  The routine dotrap
+is called at appropriate points to actually handle the signal.
+When an interrupt is caught and no trap has been set for that
+signal, the routine "onint" in error.c is called.
+
+OUTPUT:  Ash uses it's own output routines.  There are three out-
+put structures allocated.  "Output" represents the standard out-
+put, "errout" the standard error, and "memout" contains output
+which is to be stored in memory.  This last is used when a buil-
+tin command appears in backquotes, to allow its output to be col-
+lected without doing any I/O through the UNIX operating system.
+The variables out1 and out2 normally point to output and errout,
+respectively, but they are set to point to memout when appropri-
+ate inside backquotes.
+
+INPUT:  The basic input routine is pgetc, which reads from the
+current input file.  There is a stack of input files; the current
+input file is the top file on this stack.  The code allows the
+input to come from a string rather than a file.  (This is for the
+-c option and the "." and eval builtin commands.)  The global
+variable plinno is saved and restored when files are pushed and
+popped from the stack.  The parser routines store the number of
+the current line in this variable.
+
+DEBUGGING:  If DEBUG is defined in shell.h, then the shell will
+write debugging information to the file $HOME/trace.  Most of
+this is done using the TRACE macro, which takes a set of printf
+arguments inside two sets of parenthesis.  Example:
+"TRACE(("n=%d0, n))".  The double parenthesis are necessary be-
+cause the preprocessor can't handle functions with a variable
+number of arguments.  Defining DEBUG also causes the shell to
+generate a core dump if it is sent a quit signal.  The tracing
+code is in show.c.
diff --git a/src/alias.c b/src/alias.c
new file mode 100644
index 00000000..daeacbb8
--- /dev/null
+++ b/src/alias.c
@@ -0,0 +1,227 @@
+/*-
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdlib.h>
+#include "shell.h"
+#include "input.h"
+#include "output.h"
+#include "error.h"
+#include "memalloc.h"
+#include "mystring.h"
+#include "alias.h"
+#include "options.h"	/* XXX for argptr (should remove?) */
+
+#define ATABSIZE 39
+
+struct alias *atab[ATABSIZE];
+
+STATIC void setalias(const char *, const char *);
+STATIC struct alias *freealias(struct alias *);
+STATIC struct alias **__lookupalias(const char *);
+
+STATIC
+void
+setalias(const char *name, const char *val)
+{
+	struct alias *ap, **app;
+
+	app = __lookupalias(name);
+	ap = *app;
+	INTOFF;
+	if (ap) {
+		if (!(ap->flag & ALIASINUSE)) {
+			ckfree(ap->val);
+		}
+		ap->val	= savestr(val);
+		ap->flag &= ~ALIASDEAD;
+	} else {
+		/* not found */
+		ap = ckmalloc(sizeof (struct alias));
+		ap->name = savestr(name);
+		ap->val = savestr(val);
+		ap->flag = 0;
+		ap->next = 0;
+		*app = ap;
+	}
+	INTON;
+}
+
+int
+unalias(const char *name)
+{
+	struct alias **app;
+
+	app = __lookupalias(name);
+
+	if (*app) {
+		INTOFF;
+		*app = freealias(*app);
+		INTON;
+		return (0);
+	}
+
+	return (1);
+}
+
+void
+rmaliases(void)
+{
+	struct alias *ap, **app;
+	int i;
+
+	INTOFF;
+	for (i = 0; i < ATABSIZE; i++) {
+		app = &atab[i];
+		for (ap = *app; ap; ap = *app) {
+			*app = freealias(*app);
+			if (ap == *app) {
+				app = &ap->next;
+			}
+		}
+	}
+	INTON;
+}
+
+struct alias *
+lookupalias(const char *name, int check)
+{
+	struct alias *ap = *__lookupalias(name);
+
+	if (check && ap && (ap->flag & ALIASINUSE))
+		return (NULL);
+	return (ap);
+}
+
+/*
+ * TODO - sort output
+ */
+int
+aliascmd(int argc, char **argv)
+{
+	char *n, *v;
+	int ret = 0;
+	struct alias *ap;
+
+	if (argc == 1) {
+		int i;
+
+		for (i = 0; i < ATABSIZE; i++)
+			for (ap = atab[i]; ap; ap = ap->next) {
+				printalias(ap);
+			}
+		return (0);
+	}
+	while ((n = *++argv) != NULL) {
+		if ((v = strchr(n+1, '=')) == NULL) { /* n+1: funny ksh stuff */
+			if ((ap = *__lookupalias(n)) == NULL) {
+				outfmt(out2, "%s: %s not found\n", "alias", n);
+				ret = 1;
+			} else
+				printalias(ap);
+		} else {
+			*v++ = '\0';
+			setalias(n, v);
+		}
+	}
+
+	return (ret);
+}
+
+int
+unaliascmd(int argc, char **argv)
+{
+	int i;
+
+	while ((i = nextopt("a")) != '\0') {
+		if (i == 'a') {
+			rmaliases();
+			return (0);
+		}
+	}
+	for (i = 0; *argptr; argptr++) {
+		if (unalias(*argptr)) {
+			outfmt(out2, "%s: %s not found\n", "unalias", *argptr);
+			i = 1;
+		}
+	}
+
+	return (i);
+}
+
+STATIC struct alias *
+freealias(struct alias *ap) {
+	struct alias *next;
+
+	if (ap->flag & ALIASINUSE) {
+		ap->flag |= ALIASDEAD;
+		return ap;
+	}
+
+	next = ap->next;
+	ckfree(ap->name);
+	ckfree(ap->val);
+	ckfree(ap);
+	return next;
+}
+
+void
+printalias(const struct alias *ap) {
+	out1fmt("%s=%s\n", ap->name, single_quote(ap->val));
+}
+
+STATIC struct alias **
+__lookupalias(const char *name) {
+	unsigned int hashval;
+	struct alias **app;
+	const char *p;
+	unsigned int ch;
+
+	p = name;
+
+	ch = (unsigned char)*p;
+	hashval = ch << 4;
+	while (ch) {
+		hashval += ch;
+		ch = (unsigned char)*++p;
+	}
+	app = &atab[hashval % ATABSIZE];
+
+	for (; *app; app = &(*app)->next) {
+		if (equal(name, (*app)->name)) {
+			break;
+		}
+	}
+
+	return app;
+}
diff --git a/src/alias.h b/src/alias.h
new file mode 100644
index 00000000..fb841d64
--- /dev/null
+++ b/src/alias.h
@@ -0,0 +1,52 @@
+/*-
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)alias.h	8.2 (Berkeley) 5/4/95
+ */
+
+#define ALIASINUSE	1
+#define ALIASDEAD	2
+
+struct alias {
+	struct alias *next;
+	char *name;
+	char *val;
+	int flag;
+};
+
+struct alias *lookupalias(const char *, int);
+int aliascmd(int, char **);
+int unaliascmd(int, char **);
+void rmaliases(void);
+int unalias(const char *);
+void printalias(const struct alias *);
diff --git a/src/arith_yacc.c b/src/arith_yacc.c
new file mode 100644
index 00000000..1a087c32
--- /dev/null
+++ b/src/arith_yacc.c
@@ -0,0 +1,304 @@
+/*-
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 2007
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <inttypes.h>
+#include <stdlib.h>
+#include "arith_yacc.h"
+#include "expand.h"
+#include "shell.h"
+#include "error.h"
+#include "output.h"
+#include "var.h"
+
+#if ARITH_BOR + 11 != ARITH_BORASS || ARITH_ASS + 11 != ARITH_EQ
+#error Arithmetic tokens are out of order.
+#endif
+
+static const char *arith_startbuf;
+
+const char *arith_buf;
+union yystype yylval;
+
+static int last_token;
+
+#define ARITH_PRECEDENCE(op, prec) [op - ARITH_BINOP_MIN] = prec
+
+static const char prec[ARITH_BINOP_MAX - ARITH_BINOP_MIN] = {
+	ARITH_PRECEDENCE(ARITH_MUL, 0),
+	ARITH_PRECEDENCE(ARITH_DIV, 0),
+	ARITH_PRECEDENCE(ARITH_REM, 0),
+	ARITH_PRECEDENCE(ARITH_ADD, 1),
+	ARITH_PRECEDENCE(ARITH_SUB, 1),
+	ARITH_PRECEDENCE(ARITH_LSHIFT, 2),
+	ARITH_PRECEDENCE(ARITH_RSHIFT, 2),
+	ARITH_PRECEDENCE(ARITH_LT, 3),
+	ARITH_PRECEDENCE(ARITH_LE, 3),
+	ARITH_PRECEDENCE(ARITH_GT, 3),
+	ARITH_PRECEDENCE(ARITH_GE, 3),
+	ARITH_PRECEDENCE(ARITH_EQ, 4),
+	ARITH_PRECEDENCE(ARITH_NE, 4),
+	ARITH_PRECEDENCE(ARITH_BAND, 5),
+	ARITH_PRECEDENCE(ARITH_BXOR, 6),
+	ARITH_PRECEDENCE(ARITH_BOR, 7),
+};
+
+#define ARITH_MAX_PREC 8
+
+static void yyerror(const char *s) __attribute__ ((noreturn));
+static void yyerror(const char *s)
+{
+	sh_error("arithmetic expression: %s: \"%s\"", s, arith_startbuf);
+	/* NOTREACHED */
+}
+
+static inline int arith_prec(int op)
+{
+	return prec[op - ARITH_BINOP_MIN];
+}
+
+static inline int higher_prec(int op1, int op2)
+{
+	return arith_prec(op1) < arith_prec(op2);
+}
+
+static intmax_t do_binop(int op, intmax_t a, intmax_t b)
+{
+	switch (op) {
+	default:
+	case ARITH_REM:
+	case ARITH_DIV:
+		if (!b)
+			yyerror("division by zero");
+		return op == ARITH_REM ? a % b : a / b;
+	case ARITH_MUL:
+		return a * b;
+	case ARITH_ADD:
+		return a + b;
+	case ARITH_SUB:
+		return a - b;
+	case ARITH_LSHIFT:
+		return a << b;
+	case ARITH_RSHIFT:
+		return a >> b;
+	case ARITH_LT:
+		return a < b;
+	case ARITH_LE:
+		return a <= b;
+	case ARITH_GT:
+		return a > b;
+	case ARITH_GE:
+		return a >= b;
+	case ARITH_EQ:
+		return a == b;
+	case ARITH_NE:
+		return a != b;
+	case ARITH_BAND:
+		return a & b;
+	case ARITH_BXOR:
+		return a ^ b;
+	case ARITH_BOR:
+		return a | b;
+	}
+}
+
+static intmax_t assignment(int var, int noeval);
+
+static intmax_t primary(int token, union yystype *val, int op, int noeval)
+{
+	intmax_t result;
+
+again:
+	switch (token) {
+	case ARITH_LPAREN:
+		result = assignment(op, noeval);
+		if (last_token != ARITH_RPAREN)
+			yyerror("expecting ')'");
+		last_token = yylex();
+		return result;
+	case ARITH_NUM:
+		last_token = op;
+		return val->val;
+	case ARITH_VAR:
+		last_token = op;
+		return noeval ? val->val : lookupvarint(val->name);
+	case ARITH_ADD:
+		token = op;
+		*val = yylval;
+		op = yylex();
+		goto again;
+	case ARITH_SUB:
+		*val = yylval;
+		return -primary(op, val, yylex(), noeval);
+	case ARITH_NOT:
+		*val = yylval;
+		return !primary(op, val, yylex(), noeval);
+	case ARITH_BNOT:
+		*val = yylval;
+		return ~primary(op, val, yylex(), noeval);
+	default:
+		yyerror("expecting primary");
+	}
+}
+
+static intmax_t binop2(intmax_t a, int op, int prec, int noeval)
+{
+	for (;;) {
+		union yystype val;
+		intmax_t b;
+		int op2;
+		int token;
+
+		token = yylex();
+		val = yylval;
+
+		b = primary(token, &val, yylex(), noeval);
+
+		op2 = last_token;
+		if (op2 >= ARITH_BINOP_MIN && op2 < ARITH_BINOP_MAX &&
+		    higher_prec(op2, op)) {
+			b = binop2(b, op2, arith_prec(op), noeval);
+			op2 = last_token;
+		}
+
+		a = noeval ? b : do_binop(op, a, b);
+
+		if (op2 < ARITH_BINOP_MIN || op2 >= ARITH_BINOP_MAX ||
+		    arith_prec(op2) >= prec)
+			return a;
+
+		op = op2;
+	}
+}
+
+static intmax_t binop(int token, union yystype *val, int op, int noeval)
+{
+	intmax_t a = primary(token, val, op, noeval);
+
+	op = last_token;
+	if (op < ARITH_BINOP_MIN || op >= ARITH_BINOP_MAX)
+		return a;
+
+	return binop2(a, op, ARITH_MAX_PREC, noeval);
+}
+
+static intmax_t and(int token, union yystype *val, int op, int noeval)
+{
+	intmax_t a = binop(token, val, op, noeval);
+	intmax_t b;
+
+	op = last_token;
+	if (op != ARITH_AND)
+		return a;
+
+	token = yylex();
+	*val = yylval;
+
+	b = and(token, val, yylex(), noeval | !a);
+
+	return a && b;
+}
+
+static intmax_t or(int token, union yystype *val, int op, int noeval)
+{
+	intmax_t a = and(token, val, op, noeval);
+	intmax_t b;
+
+	op = last_token;
+	if (op != ARITH_OR)
+		return a;
+
+	token = yylex();
+	*val = yylval;
+
+	b = or(token, val, yylex(), noeval | !!a);
+
+	return a || b;
+}
+
+static intmax_t cond(int token, union yystype *val, int op, int noeval)
+{
+	intmax_t a = or(token, val, op, noeval);
+	intmax_t b;
+	intmax_t c;
+
+	if (last_token != ARITH_QMARK)
+		return a;
+
+	b = assignment(yylex(), noeval | !a);
+
+	if (last_token != ARITH_COLON)
+		yyerror("expecting ':'");
+
+	token = yylex();
+	*val = yylval;
+
+	c = cond(token, val, yylex(), noeval | !!a);
+
+	return a ? b : c;
+}
+
+static intmax_t assignment(int var, int noeval)
+{
+	union yystype val = yylval;
+	int op = yylex();
+	intmax_t result;
+
+	if (var != ARITH_VAR)
+		return cond(var, &val, op, noeval);
+
+	if (op != ARITH_ASS && (op < ARITH_ASS_MIN || op >= ARITH_ASS_MAX))
+		return cond(var, &val, op, noeval);
+
+	result = assignment(yylex(), noeval);
+	if (noeval)
+		return result;
+
+	return setvarint(val.name,
+			 op == ARITH_ASS ? result :
+			 do_binop(op - 11, lookupvarint(val.name), result), 0);
+}
+
+intmax_t arith(const char *s)
+{
+	intmax_t result;
+
+	arith_buf = arith_startbuf = s;
+
+	result = assignment(yylex(), 0);
+
+	if (last_token)
+		yyerror("expecting EOF");
+
+	return result;
+}
diff --git a/src/arith_yacc.h b/src/arith_yacc.h
new file mode 100644
index 00000000..ff34d524
--- /dev/null
+++ b/src/arith_yacc.h
@@ -0,0 +1,89 @@
+/*-
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 2007
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#define ARITH_ASS 1
+
+#define ARITH_OR 2
+#define ARITH_AND 3
+#define ARITH_BAD 4
+#define ARITH_NUM 5
+#define ARITH_VAR 6
+#define ARITH_NOT 7
+
+#define ARITH_BINOP_MIN 8
+#define ARITH_LE 8
+#define ARITH_GE 9
+#define ARITH_LT 10
+#define ARITH_GT 11
+#define ARITH_EQ 12
+#define ARITH_REM 13
+#define ARITH_BAND 14
+#define ARITH_LSHIFT 15
+#define ARITH_RSHIFT 16
+#define ARITH_MUL 17
+#define ARITH_ADD 18
+#define ARITH_BOR 19
+#define ARITH_SUB 20
+#define ARITH_BXOR 21
+#define ARITH_DIV 22
+#define ARITH_NE 23
+#define ARITH_BINOP_MAX 24
+
+#define ARITH_ASS_MIN 24
+#define ARITH_REMASS 24
+#define ARITH_BANDASS 25
+#define ARITH_LSHIFTASS 26
+#define ARITH_RSHIFTASS 27
+#define ARITH_MULASS 28
+#define ARITH_ADDASS 29
+#define ARITH_BORASS 30
+#define ARITH_SUBASS 31
+#define ARITH_BXORASS 32
+#define ARITH_DIVASS 33
+#define ARITH_ASS_MAX 34
+
+#define ARITH_LPAREN 34
+#define ARITH_RPAREN 35
+#define ARITH_BNOT 36
+#define ARITH_QMARK 37
+#define ARITH_COLON 38
+
+union yystype {
+	intmax_t val;
+	char *name;
+};
+
+extern union yystype yylval;
+
+int yylex(void);
diff --git a/src/arith_yylex.c b/src/arith_yylex.c
new file mode 100644
index 00000000..ec5b5b25
--- /dev/null
+++ b/src/arith_yylex.c
@@ -0,0 +1,240 @@
+/*-
+ * Copyright (c) 2002
+ *	Herbert Xu.
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+#include "arith_yacc.h"
+#include "expand.h"
+#include "error.h"
+#include "shell.h"
+#include "memalloc.h"
+#include "syntax.h"
+#include "system.h"
+
+#if ARITH_BOR + 11 != ARITH_BORASS || ARITH_ASS + 11 != ARITH_EQ
+#error Arithmetic tokens are out of order.
+#endif
+
+extern const char *arith_buf;
+
+int
+yylex()
+{
+	int value;
+	const char *buf = arith_buf;
+	const char *p;
+
+	for (;;) {
+		value = *buf;
+		switch (value) {
+		case ' ':
+		case '\t':
+		case '\n':
+			buf++;
+			continue;
+		default:
+			return ARITH_BAD;
+		case '0':
+		case '1':
+		case '2':
+		case '3':
+		case '4':
+		case '5':
+		case '6':
+		case '7':
+		case '8':
+		case '9':
+			yylval.val = strtoimax(buf, (char **)&arith_buf, 0);
+			return ARITH_NUM;
+		case 'A':
+		case 'B':
+		case 'C':
+		case 'D':
+		case 'E':
+		case 'F':
+		case 'G':
+		case 'H':
+		case 'I':
+		case 'J':
+		case 'K':
+		case 'L':
+		case 'M':
+		case 'N':
+		case 'O':
+		case 'P':
+		case 'Q':
+		case 'R':
+		case 'S':
+		case 'T':
+		case 'U':
+		case 'V':
+		case 'W':
+		case 'X':
+		case 'Y':
+		case 'Z':
+		case '_':
+		case 'a':
+		case 'b':
+		case 'c':
+		case 'd':
+		case 'e':
+		case 'f':
+		case 'g':
+		case 'h':
+		case 'i':
+		case 'j':
+		case 'k':
+		case 'l':
+		case 'm':
+		case 'n':
+		case 'o':
+		case 'p':
+		case 'q':
+		case 'r':
+		case 's':
+		case 't':
+		case 'u':
+		case 'v':
+		case 'w':
+		case 'x':
+		case 'y':
+		case 'z':
+			p = buf;
+			while (buf++, is_in_name(*buf))
+				;
+			yylval.name = stalloc(buf - p + 1);
+			*(char *)mempcpy(yylval.name, p, buf - p) = 0;
+			value = ARITH_VAR;
+			goto out;
+		case '=':
+			value += ARITH_ASS - '=';
+checkeq:
+			buf++;
+checkeqcur:
+			if (*buf != '=')
+				goto out;
+			value += 11;
+			break;
+		case '>':
+			switch (*++buf) {
+			case '=':
+				value += ARITH_GE - '>';
+				break;
+			case '>':
+				value += ARITH_RSHIFT - '>';
+				goto checkeq;
+			default:
+				value += ARITH_GT - '>';
+				goto out;
+			}
+			break;
+		case '<':
+			switch (*++buf) {
+			case '=':
+				value += ARITH_LE - '<';
+				break;
+			case '<':
+				value += ARITH_LSHIFT - '<';
+				goto checkeq;
+			default:
+				value += ARITH_LT - '<';
+				goto out;
+			}
+			break;
+		case '|':
+			if (*++buf != '|') {
+				value += ARITH_BOR - '|';
+				goto checkeqcur;
+			}
+			value += ARITH_OR - '|';
+			break;
+		case '&':
+			if (*++buf != '&') {
+				value += ARITH_BAND - '&';
+				goto checkeqcur;
+			}
+			value += ARITH_AND - '&';
+			break;
+		case '!':
+			if (*++buf != '=') {
+				value += ARITH_NOT - '!';
+				goto out;
+			}
+			value += ARITH_NE - '!';
+			break;
+		case 0:
+			goto out;
+		case '(':
+			value += ARITH_LPAREN - '(';
+			break;
+		case ')':
+			value += ARITH_RPAREN - ')';
+			break;
+		case '*':
+			value += ARITH_MUL - '*';
+			goto checkeq;
+		case '/':
+			value += ARITH_DIV - '/';
+			goto checkeq;
+		case '%':
+			value += ARITH_REM - '%';
+			goto checkeq;
+		case '+':
+			value += ARITH_ADD - '+';
+			goto checkeq;
+		case '-':
+			value += ARITH_SUB - '-';
+			goto checkeq;
+		case '~':
+			value += ARITH_BNOT - '~';
+			break;
+		case '^':
+			value += ARITH_BXOR - '^';
+			goto checkeq;
+		case '?':
+			value += ARITH_QMARK - '?';
+			break;
+		case ':':
+			value += ARITH_COLON - ':';
+			break;
+		}
+		break;
+	}
+
+	buf++;
+out:
+	arith_buf = buf;
+	return value;
+}
diff --git a/src/bltin/bltin.h b/src/bltin/bltin.h
new file mode 100644
index 00000000..f5ac06f2
--- /dev/null
+++ b/src/bltin/bltin.h
@@ -0,0 +1,89 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)bltin.h	8.1 (Berkeley) 5/31/93
+ */
+
+/*
+ * This file is included by programs which are optionally built into the
+ * shell.  If SHELL is defined, we try to map the standard UNIX library
+ * routines to ash routines using defines.
+ */
+
+#include "../shell.h"
+#include "../mystring.h"
+#include "../options.h"
+#ifdef SHELL
+#include "../memalloc.h"
+#include "../output.h"
+#include "../error.h"
+#ifndef USE_GLIBC_STDIO
+#undef stdout
+#undef stderr
+#undef putc
+#undef putchar
+#undef fileno
+#define stdout out1
+#define stderr out2
+#define printf out1fmt
+#define putc(c, file)	outc(c, file)
+#define putchar(c)	out1c(c)
+#define FILE struct output
+#define fprintf outfmt
+#define fputs outstr
+#define fflush flushout
+#define fileno(f) ((f)->fd)
+#define ferror outerr
+#endif
+#define INITARGS(argv)
+#define	error sh_error
+#define	warn sh_warn
+#define	warnx sh_warnx
+#define exit sh_exit
+#define setprogname(s)
+#define getprogname() commandname
+#define setlocate(l,s) 0
+
+#define getenv(p) bltinlookup((p),0)
+
+#else
+#undef NULL
+#include <stdio.h>
+#undef main
+#define INITARGS(argv)	if ((commandname = argv[0]) == NULL) {fputs("Argc is zero\n", stderr); exit(2);} else
+#endif
+
+int echocmd(int, char **);
+
+
+extern const char *commandname;
diff --git a/src/bltin/echo.1 b/src/bltin/echo.1
new file mode 100644
index 00000000..fbc7fb43
--- /dev/null
+++ b/src/bltin/echo.1
@@ -0,0 +1,109 @@
+.\" Copyright (c) 1991, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\" Copyright (c) 1997-2005
+.\"	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" Kenneth Almquist.
+.\" Copyright 1989 by Kenneth Almquist
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)echo.1	8.1 (Berkeley) 5/31/93
+.\"
+.Dd May 31, 1993
+.Dt ECHO 1
+.Os
+.Sh NAME
+.Nm echo
+.Nd produce message in a shell script
+.Sh SYNOPSIS
+.Nm
+.Op Fl n | Fl e
+.Ar args ...
+.Sh DESCRIPTION
+.Nm
+prints its arguments on the standard output, separated by spaces.
+Unless the
+.Fl n
+option is present, a newline is output following the arguments.
+The
+.Fl e
+option causes
+.Nm
+to treat the escape sequences specially, as described in the following
+paragraph.
+The
+.Fl e
+option is the default, and is provided solely for compatibility with
+other systems.
+Only one of the options
+.Fl n
+and
+.Fl e
+may be given.
+.Pp
+If any of the following sequences of characters is encountered during
+output, the sequence is not output.  Instead, the specified action is
+performed:
+.Bl -tag -width indent
+.It Li \eb
+A backspace character is output.
+.It Li \ec
+Subsequent output is suppressed.  This is normally used at the end of the
+last argument to suppress the trailing newline that
+.Nm
+would otherwise output.
+.It Li \ef
+Output a form feed.
+.It Li \en
+Output a newline character.
+.It Li \er
+Output a carriage return.
+.It Li \et
+Output a (horizontal) tab character.
+.It Li \ev
+Output a vertical tab.
+.It Li \e0 Ns Ar digits
+Output the character whose value is given by zero to three digits.
+If there are zero digits, a nul character is output.
+.It Li \e\e
+Output a backslash.
+.El
+.Sh HINTS
+Remember that backslash is special to the shell and needs to be escaped.
+To output a message to standard error, say
+.Pp
+.D1  echo message \*[Gt]\*[Am]2
+.Sh BUGS
+The octal character escape mechanism
+.Pq Li \e0 Ns Ar digits
+differs from the
+C language mechanism.
+.Pp
+There is no way to force
+.Nm
+to treat its arguments literally, rather than interpreting them as
+options and escape sequences.
diff --git a/src/bltin/printf.1 b/src/bltin/printf.1
new file mode 100644
index 00000000..38731732
--- /dev/null
+++ b/src/bltin/printf.1
@@ -0,0 +1,354 @@
+.\" Copyright (c) 1989, 1990, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\" Copyright (c) 1997-2005
+.\"	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" the Institute of Electrical and Electronics Engineers, Inc.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	from: @(#)printf.1	8.1 (Berkeley) 6/6/93
+.\"
+.Dd November 5, 1993
+.Dt PRINTF 1
+.Os
+.Sh NAME
+.Nm printf
+.Nd formatted output
+.Sh SYNOPSIS
+.Nm
+.Ar format
+.Op Ar arguments  ...
+.Sh DESCRIPTION
+.Nm
+formats and prints its arguments, after the first, under control
+of the
+.Ar format  .
+The
+.Ar format
+is a character string which contains three types of objects: plain characters,
+which are simply copied to standard output, character escape sequences which
+are converted and copied to the standard output, and format specifications,
+each of which causes printing of the next successive
+.Ar argument  .
+.Pp
+The
+.Ar arguments
+after the first are treated as strings if the corresponding format is
+either
+.Cm b ,
+.Cm B ,
+.Cm c
+or
+.Cm s ;
+otherwise it is evaluated as a C constant, with the following extensions:
+.Pp
+.Bl -bullet -offset indent -compact
+.It
+A leading plus or minus sign is allowed.
+.It
+If the leading character is a single or double quote, the value is the
+.Tn ASCII
+code of the next character.
+.El
+.Pp
+The format string is reused as often as necessary to satisfy the
+.Ar arguments  .
+Any extra format specifications are evaluated with zero or the null
+string.
+.Pp
+Character escape sequences are in backslash notation as defined in
+.St -ansiC .
+The characters and their meanings are as follows:
+.Bl -tag -width Ds -offset indent
+.It Cm \ee
+Write an \*[Lt]escape\*[Gt] character.
+.It Cm \ea
+Write a \*[Lt]bell\*[Gt] character.
+.It Cm \eb
+Write a \*[Lt]backspace\*[Gt] character.
+.It Cm \ef
+Write a \*[Lt]form-feed\*[Gt] character.
+.It Cm \en
+Write a \*[Lt]new-line\*[Gt] character.
+.It Cm \er
+Write a \*[Lt]carriage return\*[Gt] character.
+.It Cm \et
+Write a \*[Lt]tab\*[Gt] character.
+.It Cm \ev
+Write a \*[Lt]vertical tab\*[Gt] character.
+.It Cm \e\'
+Write a \*[Lt]single quote\*[Gt] character.
+.It Cm \e"
+Write a \*[Lt]double quote\*[Gt] character.
+.It Cm \e\e
+Write a backslash character.
+.It Cm \e Ns Ar num
+Write an 8\-bit character whose
+.Tn ASCII
+value is the 1\-, 2\-, or 3\-digit octal number
+.Ar num .
+.It Cm \ex Ns Ar xx
+Write an 8\-bit character whose
+.Tn ASCII
+value is the 1\- or 2\-digit hexadecimal number
+.Ar xx .
+.El
+.Pp
+Each format specification is introduced by the percent character
+(``%'').
+The remainder of the format specification includes,
+in the following order:
+.Bl -tag -width Ds
+.It "Zero or more of the following flags:"
+.Bl -tag -width Ds
+.It Cm #
+A `#' character
+specifying that the value should be printed in an ``alternative form''.
+For
+.Cm b ,
+.Cm c ,
+.Cm d ,
+and
+.Cm s
+formats, this option has no effect.
+For the
+.Cm o
+format the precision of the number is increased to force the first
+character of the output string to a zero.
+For the
+.Cm x
+.Pq Cm X
+format, a non-zero result has the string
+.Li 0x
+.Pq Li 0X
+prepended to it.
+For
+.Cm e  ,
+.Cm E ,
+.Cm f  ,
+.Cm g ,
+and
+.Cm G
+formats, the result will always contain a decimal point, even if no
+digits follow the point (normally, a decimal point only appears in the
+results of those formats if a digit follows the decimal point).
+For
+.Cm g
+and
+.Cm G
+formats, trailing zeros are not removed from the result as they
+would otherwise be.
+.\" I turned this off - decided it isn't a valid use of '#'
+.\" For the
+.\" .Cm B
+.\" format, backslash-escape sequences are expanded first;
+.It Cm \&\-
+A minus sign `\-' which specifies
+.Em left adjustment
+of the output in the indicated field;
+.It Cm \&+
+A `+' character specifying that there should always be
+a sign placed before the number when using signed formats.
+.It Sq \&\ \&
+A space specifying that a blank should be left before a positive number
+for a signed format.
+A `+' overrides a space if both are used;
+.It Cm \&0
+A zero `0' character indicating that zero-padding should be used
+rather than blank-padding.
+A `\-' overrides a `0' if both are used;
+.El
+.It "Field Width:"
+An optional digit string specifying a
+.Em field width ;
+if the output string has fewer characters than the field width it will
+be blank-padded on the left (or right, if the left-adjustment indicator
+has been given) to make up the field width (note that a leading zero
+is a flag, but an embedded zero is part of a field width);
+.It Precision :
+An optional period,
+.Sq Cm \&.\& ,
+followed by an optional digit string giving a
+.Em precision
+which specifies the number of digits to appear after the decimal point,
+for
+.Cm e
+and
+.Cm f
+formats, or the maximum number of characters to be printed
+from a string
+.Sm off
+.Pf ( Cm b No ,
+.Sm on
+.Cm B
+and
+.Cm s
+formats); if the digit string is missing, the precision is treated
+as zero;
+.It Format :
+A character which indicates the type of format to use (one of
+.Cm diouxXfwEgGbBcs ) .
+.El
+.Pp
+A field width or precision may be
+.Sq Cm \&*
+instead of a digit string.
+In this case an
+.Ar argument
+supplies the field width or precision.
+.Pp
+The format characters and their meanings are:
+.Bl -tag -width Fl
+.It Cm diouXx
+The
+.Ar argument
+is printed as a signed decimal (d or i), unsigned octal, unsigned decimal,
+or unsigned hexadecimal (X or x), respectively.
+.It Cm f
+The
+.Ar argument
+is printed in the style
+.Sm off
+.Pf [\-]ddd Cm \&. No ddd
+.Sm on
+where the number of d's
+after the decimal point is equal to the precision specification for
+the argument.
+If the precision is missing, 6 digits are given; if the precision
+is explicitly 0, no digits and no decimal point are printed.
+.It Cm eE
+The
+.Ar argument
+is printed in the style
+.Sm off
+.Pf [\-]d Cm \&. No ddd Cm e No \\*(Pmdd
+.Sm on
+where there
+is one digit before the decimal point and the number after is equal to
+the precision specification for the argument; when the precision is
+missing, 6 digits are produced.
+An upper-case E is used for an `E' format.
+.It Cm gG
+The
+.Ar argument
+is printed in style
+.Cm f
+or in style
+.Cm e
+.Pq Cm E
+whichever gives full precision in minimum space.
+.It Cm b
+Characters from the string
+.Ar argument
+are printed with backslash-escape sequences expanded.
+.br
+The following additional backslash-escape sequences are supported:
+.Bl -tag -width Ds
+.It Cm \ec
+Causes
+.Nm
+to ignore any remaining characters in the string operand containing it,
+any remaining string operands, and any additional characters in
+the format operand.
+.It Cm \e0 Ns Ar num
+Write an 8\-bit character whose
+.Tn ASCII
+value is the 1\-, 2\-, or 3\-digit
+octal number
+.Ar num .
+.It Cm \e^ Ns Ar c
+Write the control character 
+.Ar c .
+Generates characters `\e000' through `\e037`, and `\e177' (from `\e^?').
+.It Cm \eM\- Ns Ar c
+Write the character 
+.Ar c
+with the 8th bit set.
+Generates characters `\e241' through `\e376`.
+.It Cm \eM^ Ns Ar c
+Write the control character 
+.Ar c
+with the 8th bit set.
+Generates characters `\e000' through `\e037`, and `\e177' (from `\eM^?').
+.El
+.It Cm B
+Characters from the string
+.Ar argument
+are printed with unprintable characters backslash-escaped using the
+.Sm off
+.Pf ` Cm \e Ar c No ',
+.Pf ` Cm \e^ Ar c No ',
+.Pf ` Cm \eM\- Ar c No '
+or
+.Pf ` Cm \eM^ Ar c No ',
+.Sm on
+formats described above.
+.It Cm c
+The first character of
+.Ar argument
+is printed.
+.It Cm s
+Characters from the string
+.Ar argument
+are printed until the end is reached or until the number of characters
+indicated by the precision specification is reached; if the
+precision is omitted, all characters in the string are printed.
+.It Cm \&%
+Print a `%'; no argument is used.
+.El
+.Pp
+In no case does a non-existent or small field width cause truncation of
+a field; padding takes place only if the specified field width exceeds
+the actual width.
+.Sh EXIT STATUS
+.Nm
+exits 0 on success, 1 on failure.
+.Sh SEE ALSO
+.Xr echo 1 ,
+.Xr printf 3 ,
+.Xr printf 9
+.Xr vis 3
+.Sh STANDARDS
+The
+.Nm
+utility conforms to
+.St -p1003.1-2001 .
+.Pp
+Support for the floating point formats and `*' as a field width and precision
+are optional in POSIX.
+.Pp
+The behaviour of the %B format and the \e', \e", \exxx, \ee and
+\e[M][\-|^]c escape sequences are undefined in POSIX.
+.Sh BUGS
+Since the floating point numbers are translated from
+.Tn ASCII
+to floating-point and
+then back again, floating-point precision may be lost.
+.Pp
+Hexadecimal character constants are restricted to, and should be specified
+as, two character constants.  This is contrary to the ISO C standard but
+does guarantee detection of the end of the constant.
diff --git a/src/bltin/printf.c b/src/bltin/printf.c
new file mode 100644
index 00000000..7785735b
--- /dev/null
+++ b/src/bltin/printf.c
@@ -0,0 +1,478 @@
+/*
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static int	 conv_escape_str(char *, char **);
+static char	*conv_escape(char *, int *);
+static int	 getchr(void);
+static double	 getdouble(void);
+static uintmax_t getuintmax(int);
+static char	*getstr(void);
+static char	*mklong(const char *, const char *);
+static void      check_conversion(const char *, const char *);
+
+static int	rval;
+static char  **gargv;
+
+#define isodigit(c)	((c) >= '0' && (c) <= '7')
+#define octtobin(c)	((c) - '0')
+
+#include "bltin.h"
+#include "system.h"
+
+#define PF(f, func) { \
+	switch ((char *)param - (char *)array) { \
+	default: \
+		(void)printf(f, array[0], array[1], func); \
+		break; \
+	case sizeof(*param): \
+		(void)printf(f, array[0], func); \
+		break; \
+	case 0: \
+		(void)printf(f, func); \
+		break; \
+	} \
+}
+
+#define ASPF(sp, f, func) ({ \
+	int ret; \
+	switch ((char *)param - (char *)array) { \
+	default: \
+		ret = xasprintf(sp, f, array[0], array[1], func); \
+		break; \
+	case sizeof(*param): \
+		ret = xasprintf(sp, f, array[0], func); \
+		break; \
+	case 0: \
+		ret = xasprintf(sp, f, func); \
+		break; \
+	} \
+	ret; \
+})
+
+
+static int print_escape_str(const char *f, int *param, int *array, char *s)
+{
+	struct stackmark smark;
+	char *p, *q;
+	int done;
+	int len;
+	int total;
+
+	setstackmark(&smark);
+	done = conv_escape_str(s, &q);
+	p = stackblock();
+	len = q - p;
+	total = len - 1;
+
+	q[-1] = (!!((f[1] - 's') | done) - 1) & f[2];
+	total += !!q[-1];
+	if (f[1] == 's')
+		goto easy;
+
+	p = makestrspace(len, q);
+	memset(p, 'X', total);
+	p[total] = 0;
+
+	q = stackblock();
+	total = ASPF(&p, f, p);
+
+	len = strchrnul(p, 'X') - p;
+	memcpy(p + len, q, strspn(p + len, "X"));
+
+easy:
+	out1mem(p, total);
+
+	popstackmark(&smark);
+	return done;
+}
+
+
+int printfcmd(int argc, char *argv[])
+{
+	char *fmt;
+	char *format;
+	int ch;
+
+	rval = 0;
+
+	nextopt(nullstr);
+
+	argv = argptr;
+	format = *argv;
+
+	if (!format)
+		error("usage: printf format [arg ...]");
+
+	gargv = ++argv;
+
+#define SKIP1	"#-+ 0"
+#define SKIP2	"*0123456789"
+	do {
+		/*
+		 * Basic algorithm is to scan the format string for conversion
+		 * specifications -- once one is found, find out if the field
+		 * width or precision is a '*'; if it is, gather up value. 
+		 * Note, format strings are reused as necessary to use up the
+		 * provided arguments, arguments of zero/null string are 
+		 * provided to use up the format string.
+		 */
+
+		/* find next format specification */
+		for (fmt = format; (ch = *fmt++) ;) {
+			char *start;
+			char nextch;
+			int array[2];
+			int *param;
+
+			if (ch == '\\') {
+				int c_ch;
+				fmt = conv_escape(fmt, &c_ch);
+				ch = c_ch;
+				goto pc;
+			}
+			if (ch != '%' || (*fmt == '%' && (++fmt || 1))) {
+pc:
+				putchar(ch);
+				continue;
+			}
+
+			/* Ok - we've found a format specification,
+			   Save its address for a later printf(). */
+			start = fmt - 1;
+			param = array;
+
+			/* skip to field width */
+			fmt += strspn(fmt, SKIP1);
+			if (*fmt == '*') {
+				++fmt;
+				*param++ = getuintmax(1);
+			} else {
+				/* skip to possible '.',
+				 * get following precision
+				 */
+				fmt += strspn(fmt, SKIP2);
+			}
+
+			if (*fmt == '.') {
+				++fmt;
+				if (*fmt == '*') {
+					++fmt;
+					*param++ = getuintmax(1);
+				} else
+					fmt += strspn(fmt, SKIP2);
+			}
+
+			ch = *fmt;
+			if (!ch)
+				error("missing format character");
+			/* null terminate format string to we can use it
+			   as an argument to printf. */
+			nextch = fmt[1];
+			fmt[1] = 0;
+			switch (ch) {
+
+			case 'b':
+				*fmt = 's';
+				/* escape if a \c was encountered */
+				if (print_escape_str(start, param, array,
+						     getstr()))
+					goto out;
+				*fmt = 'b';
+				break;
+			case 'c': {
+				int p = getchr();
+				PF(start, p);
+				break;
+			}
+			case 's': {
+				char *p = getstr();
+				PF(start, p);
+				break;
+			}
+			case 'd':
+			case 'i': {
+				uintmax_t p = getuintmax(1);
+				start = mklong(start, fmt);
+				PF(start, p);
+				break;
+			}
+			case 'o':
+			case 'u':
+			case 'x':
+			case 'X': {
+				uintmax_t p = getuintmax(0);
+				start = mklong(start, fmt);
+				PF(start, p);
+				break;
+			}
+			case 'a':
+			case 'A':
+			case 'e':
+			case 'E':
+			case 'f':
+			case 'F':
+			case 'g':
+			case 'G': {
+				double p = getdouble();
+				PF(start, p);
+				break;
+			}
+			default:
+				error("%s: invalid directive", start);
+			}
+			*++fmt = nextch;
+		}
+	} while (gargv != argv && *gargv);
+
+out:
+	return rval;
+}
+
+
+/*
+ * Print SysV echo(1) style escape string 
+ *	Halts processing string if a \c escape is encountered.
+ */
+static int
+conv_escape_str(char *str, char **sp)
+{
+	int c;
+	int ch;
+	char *cp;
+
+	/* convert string into a temporary buffer... */
+	STARTSTACKSTR(cp);
+
+	do {
+		c = ch = *str++;
+		if (ch != '\\')
+			continue;
+
+		c = *str++;
+		if (c == 'c') {
+			/* \c as in SYSV echo - abort all processing.... */
+			c = ch = 0x100;
+			continue;
+		}
+
+		/* 
+		 * %b string octal constants are not like those in C.
+		 * They start with a \0, and are followed by 0, 1, 2, 
+		 * or 3 octal digits. 
+		 */
+		if (c == '0' && isodigit(*str))
+			str++;
+
+		/* Finally test for sequences valid in the format string */
+		str = conv_escape(str - 1, &c);
+	} while (STPUTC(c, cp), (char)ch);
+
+	*sp = cp;
+
+	return ch;
+}
+
+/*
+ * Print "standard" escape characters 
+ */
+static char *
+conv_escape(char *str, int *conv_ch)
+{
+	int value;
+	int ch;
+
+	ch = *str;
+
+	switch (ch) {
+	default:
+		if (!isodigit(*str)) {
+			value = '\\';
+			goto out;
+		}
+
+		ch = 3;
+		value = 0;
+		do {
+			value <<= 3;
+			value += octtobin(*str++);
+		} while (isodigit(*str) && --ch);
+		goto out;
+
+	case '\\':	value = '\\';	break;	/* backslash */
+	case 'a':	value = '\a';	break;	/* alert */
+	case 'b':	value = '\b';	break;	/* backspace */
+	case 'f':	value = '\f';	break;	/* form-feed */
+	case 'n':	value = '\n';	break;	/* newline */
+	case 'r':	value = '\r';	break;	/* carriage-return */
+	case 't':	value = '\t';	break;	/* tab */
+	case 'v':	value = '\v';	break;	/* vertical-tab */
+	}
+
+	str++;
+out:
+	*conv_ch = value;
+	return str;
+}
+
+static char *
+mklong(const char *str, const char *ch)
+{
+	/*
+	 * Replace a string like "%92.3u" with "%92.3"PRIuMAX.
+	 *
+	 * Although C99 does not guarantee it, we assume PRIiMAX,
+	 * PRIoMAX, PRIuMAX, PRIxMAX, and PRIXMAX are all the same
+	 * as PRIdMAX with the final 'd' replaced by the corresponding
+	 * character.
+	 */
+
+	char *copy;
+	size_t len;	
+
+	len = ch - str + sizeof(PRIdMAX);
+	STARTSTACKSTR(copy);
+	copy = makestrspace(len, copy);
+	memcpy(copy, str, len - sizeof(PRIdMAX));
+	memcpy(copy + len - sizeof(PRIdMAX), PRIdMAX, sizeof(PRIdMAX));
+	copy[len - 2] = *ch;
+	return (copy);	
+}
+
+static int
+getchr(void)
+{
+	int val = 0;
+
+	if (*gargv)
+		val = **gargv++;
+	return val;
+}
+
+static char *
+getstr(void)
+{
+	char *val = nullstr;
+
+	if (*gargv)
+		val = *gargv++;
+	return val;
+}
+
+static uintmax_t
+getuintmax(int sign)
+{
+	uintmax_t val = 0;
+	char *cp, *ep;
+
+	cp = *gargv;
+	if (cp == NULL)
+		goto out;
+	gargv++;
+
+	val = (unsigned char) cp[1];
+	if (*cp == '\"' || *cp == '\'')
+		goto out;
+
+	errno = 0;
+	val = sign ? strtoimax(cp, &ep, 0) : strtoumax(cp, &ep, 0);
+	check_conversion(cp, ep);
+out:
+	return val;
+}
+
+static double
+getdouble(void)
+{
+	double val;
+	char *cp, *ep;
+
+	cp = *gargv;
+	if (cp == NULL)
+		return 0;
+	gargv++;
+
+	if (*cp == '\"' || *cp == '\'')
+		return (unsigned char) cp[1];
+
+	errno = 0;
+	val = strtod(cp, &ep);
+	check_conversion(cp, ep);
+	return val;
+}
+
+static void
+check_conversion(const char *s, const char *ep)
+{
+	if (*ep) {
+		if (ep == s)
+			warnx("%s: expected numeric value", s);
+		else
+			warnx("%s: not completely converted", s);
+		rval = 1;
+	} else if (errno == ERANGE) {
+		warnx("%s: %s", s, strerror(ERANGE));
+		rval = 1;
+	}
+}
+
+int
+echocmd(int argc, char **argv)
+{
+	const char *lastfmt = snlfmt;
+	int nonl;
+
+	if (*++argv && equal(*argv, "-n")) {
+		argv++;
+		lastfmt = "%s";
+	}
+
+	do {
+		const char *fmt = "%s ";
+		char *s = *argv;
+
+		if (!s || !*++argv)
+			fmt = lastfmt;
+
+		nonl = print_escape_str(fmt, NULL, NULL, s ?: nullstr);
+	} while (!nonl && *argv);
+	return 0;
+}
diff --git a/src/bltin/test.1 b/src/bltin/test.1
new file mode 100644
index 00000000..42435fb3
--- /dev/null
+++ b/src/bltin/test.1
@@ -0,0 +1,309 @@
+.\" Copyright (c) 1991, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\" Copyright (c) 1997-2005
+.\"	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" the Institute of Electrical and Electronics Engineers, Inc.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"     @(#)test.1	8.1 (Berkeley) 5/31/93
+.\"
+.Dd May 31, 1993
+.Dt TEST 1
+.Os
+.Sh NAME
+.Nm test ,
+.Nm \&[
+.Nd condition evaluation utility
+.Sh SYNOPSIS
+.Nm test
+.Ar expression
+.Nm \&[
+.Ar expression Cm ]
+.Sh DESCRIPTION
+The
+.Nm test
+utility evaluates the expression and, if it evaluates
+to true, returns a zero (true) exit status; otherwise
+it returns 1 (false).
+If there is no expression, test also
+returns 1 (false).
+.Pp
+All operators and flags are separate arguments to the
+.Nm test
+utility.
+.Pp
+The following primaries are used to construct expression:
+.Bl -tag -width Ar
+.It Fl b Ar file
+True if
+.Ar file
+exists and is a block special
+file.
+.It Fl c Ar file
+True if
+.Ar file
+exists and is a character
+special file.
+.It Fl d Ar file
+True if
+.Ar file
+exists and is a directory.
+.It Fl e Ar file
+True if
+.Ar file
+exists (regardless of type).
+.It Fl f Ar file
+True if
+.Ar file
+exists and is a regular file.
+.It Fl g Ar file
+True if
+.Ar file
+exists and its set group ID flag
+is set.
+.It Fl h Ar file
+True if
+.Ar file
+exists and is a symbolic link.
+.It Fl k Ar file
+True if
+.Ar file
+exists and its sticky bit is set.
+.It Fl n Ar string
+True if the length of
+.Ar string
+is nonzero.
+.It Fl p Ar file
+True if
+.Ar file
+is a named pipe
+.Po Tn FIFO Pc .
+.It Fl r Ar file
+True if
+.Ar file
+exists and is readable.
+.It Fl s Ar file
+True if
+.Ar file
+exists and has a size greater
+than zero.
+.It Fl t Ar file_descriptor
+True if the file whose file descriptor number
+is
+.Ar file_descriptor
+is open and is associated with a terminal.
+.It Fl u Ar file
+True if
+.Ar file
+exists and its set user ID flag
+is set.
+.It Fl w Ar file
+True if
+.Ar file
+exists and is writable.
+True
+indicates only that the write flag is on.
+The file is not writable on a read-only file
+system even if this test indicates true.
+.It Fl x Ar file
+True if
+.Ar file
+exists and is executable.
+True
+indicates only that the execute flag is on.
+If
+.Ar file
+is a directory, true indicates that
+.Ar file
+can be searched.
+.It Fl z Ar string
+True if the length of
+.Ar string
+is zero.
+.It Fl L Ar file
+True if
+.Ar file
+exists and is a symbolic link.
+This operator is retained for compatibility with previous versions of
+this program.
+Do not rely on its existence; use
+.Fl h
+instead.
+.It Fl O Ar file
+True if
+.Ar file
+exists and its owner matches the effective user id of this process.
+.It Fl G Ar file
+True if
+.Ar file
+exists and its group matches the effective group id of this process.
+.It Fl S Ar file
+True if
+.Ar file
+exists and is a socket.
+.It Ar file1 Fl nt Ar file2
+True if
+.Ar file1
+exists and is newer than
+.Ar file2 .
+.It Ar file1 Fl ot Ar file2
+True if
+.Ar file1
+exists and is older than
+.Ar file2 .
+.It Ar file1 Fl ef Ar file2
+True if
+.Ar file1
+and
+.Ar file2
+exist and refer to the same file.
+.It Ar string
+True if
+.Ar string
+is not the null
+string.
+.It Ar \&s\&1 Cm \&= Ar \&s\&2
+True if the strings
+.Ar \&s\&1
+and
+.Ar \&s\&2
+are identical.
+.It Ar \&s\&1 Cm \&!= Ar \&s\&2
+True if the strings
+.Ar \&s\&1
+and
+.Ar \&s\&2
+are not identical.
+.It Ar \&s\&1 Cm \&\*[Lt] Ar \&s\&2
+True if string
+.Ar \&s\&1
+comes before
+.Ar \&s\&2
+based on the ASCII value of their characters.
+.It Ar \&s\&1 Cm \&\*[Gt] Ar \&s\&2
+True if string
+.Ar \&s\&1
+comes after
+.Ar \&s\&2
+based on the ASCII value of their characters.
+.It Ar \&n\&1 Fl \&eq Ar \&n\&2
+True if the integers
+.Ar \&n\&1
+and
+.Ar \&n\&2
+are algebraically
+equal.
+.It Ar \&n\&1 Fl \&ne Ar \&n\&2
+True if the integers
+.Ar \&n\&1
+and
+.Ar \&n\&2
+are not
+algebraically equal.
+.It Ar \&n\&1 Fl \&gt Ar \&n\&2
+True if the integer
+.Ar \&n\&1
+is algebraically
+greater than the integer
+.Ar \&n\&2 .
+.It Ar \&n\&1 Fl \&ge Ar \&n\&2
+True if the integer
+.Ar \&n\&1
+is algebraically
+greater than or equal to the integer
+.Ar \&n\&2 .
+.It Ar \&n\&1 Fl \&lt Ar \&n\&2
+True if the integer
+.Ar \&n\&1
+is algebraically less
+than the integer
+.Ar \&n\&2 .
+.It Ar \&n\&1 Fl \&le Ar \&n\&2
+True if the integer
+.Ar \&n\&1
+is algebraically less
+than or equal to the integer
+.Ar \&n\&2 .
+.El
+.Pp
+These primaries can be combined with the following operators:
+.Bl -tag -width Ar
+.It Cm \&! Ar expression
+True if
+.Ar expression
+is false.
+.It Ar expression1 Fl a Ar expression2
+True if both
+.Ar expression1
+and
+.Ar expression2
+are true.
+.It Ar expression1 Fl o Ar expression2
+True if either
+.Ar expression1
+or
+.Ar expression2
+are true.
+.It Cm \&( Ns Ar expression Ns Cm \&)
+True if expression is true.
+.El
+.Pp
+The
+.Fl a
+operator has higher precedence than the
+.Fl o
+operator.
+.Sh GRAMMAR AMBIGUITY
+The
+.Nm test
+grammar is inherently ambiguous.
+In order to assure a degree of consistency, the cases described in
+.St -p1003.2
+section 4.62.4,
+are evaluated consistently according to the rules specified in the
+standards document.
+All other cases are subject to the ambiguity in the command semantics.
+.Sh EXIT STATUS
+The
+.Nm test
+utility exits with one of the following values:
+.Bl -tag -width Ds
+.It 0
+expression evaluated to true.
+.It 1
+expression evaluated to false or expression was
+missing.
+.It \*[Gt]1
+An error occurred.
+.El
+.Sh STANDARDS
+The
+.Nm test
+utility implements a superset of the
+.St -p1003.2
+specification.
diff --git a/src/bltin/test.c b/src/bltin/test.c
new file mode 100644
index 00000000..c7fc479d
--- /dev/null
+++ b/src/bltin/test.c
@@ -0,0 +1,700 @@
+/*
+ * test(1); version 7-like  --  author Erik Baalbergen
+ * modified by Eric Gisin to be used as built-in.
+ * modified by Arnold Robbins to add SVR3 compatibility
+ * (-x -c -b -p -u -g -k) plus Korn's -L -nt -ot -ef and new -S (socket).
+ * modified by J.T. Conklin for NetBSD.
+ *
+ * This program is in the Public Domain.
+ */
+
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include "bltin.h"
+
+/* test(1) accepts the following grammar:
+	oexpr	::= aexpr | aexpr "-o" oexpr ;
+	aexpr	::= nexpr | nexpr "-a" aexpr ;
+	nexpr	::= primary | "!" primary
+	primary	::= unary-operator operand
+		| operand binary-operator operand
+		| operand
+		| "(" oexpr ")"
+		;
+	unary-operator ::= "-r"|"-w"|"-x"|"-f"|"-d"|"-c"|"-b"|"-p"|
+		"-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|"-L"|"-S";
+
+	binary-operator ::= "="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"|
+			"-nt"|"-ot"|"-ef";
+	operand ::= <any legal UNIX file name>
+*/
+
+enum token {
+	EOI,
+	FILRD,
+	FILWR,
+	FILEX,
+	FILEXIST,
+	FILREG,
+	FILDIR,
+	FILCDEV,
+	FILBDEV,
+	FILFIFO,
+	FILSOCK,
+	FILSYM,
+	FILGZ,
+	FILTT,
+	FILSUID,
+	FILSGID,
+	FILSTCK,
+	FILNT,
+	FILOT,
+	FILEQ,
+	FILUID,
+	FILGID,
+	STREZ,
+	STRNZ,
+	STREQ,
+	STRNE,
+	STRLT,
+	STRGT,
+	INTEQ,
+	INTNE,
+	INTGE,
+	INTGT,
+	INTLE,
+	INTLT,
+	UNOT,
+	BAND,
+	BOR,
+	LPAREN,
+	RPAREN,
+	OPERAND
+};
+
+enum token_types {
+	UNOP,
+	BINOP,
+	BUNOP,
+	BBINOP,
+	PAREN
+};
+
+static struct t_op {
+	const char *op_text;
+	short op_num, op_type;
+} const ops [] = {
+	{"-r",	FILRD,	UNOP},
+	{"-w",	FILWR,	UNOP},
+	{"-x",	FILEX,	UNOP},
+	{"-e",	FILEXIST,UNOP},
+	{"-f",	FILREG,	UNOP},
+	{"-d",	FILDIR,	UNOP},
+	{"-c",	FILCDEV,UNOP},
+	{"-b",	FILBDEV,UNOP},
+	{"-p",	FILFIFO,UNOP},
+	{"-u",	FILSUID,UNOP},
+	{"-g",	FILSGID,UNOP},
+	{"-k",	FILSTCK,UNOP},
+	{"-s",	FILGZ,	UNOP},
+	{"-t",	FILTT,	UNOP},
+	{"-z",	STREZ,	UNOP},
+	{"-n",	STRNZ,	UNOP},
+	{"-h",	FILSYM,	UNOP},		/* for backwards compat */
+	{"-O",	FILUID,	UNOP},
+	{"-G",	FILGID,	UNOP},
+	{"-L",	FILSYM,	UNOP},
+	{"-S",	FILSOCK,UNOP},
+	{"=",	STREQ,	BINOP},
+	{"!=",	STRNE,	BINOP},
+	{"<",	STRLT,	BINOP},
+	{">",	STRGT,	BINOP},
+	{"-eq",	INTEQ,	BINOP},
+	{"-ne",	INTNE,	BINOP},
+	{"-ge",	INTGE,	BINOP},
+	{"-gt",	INTGT,	BINOP},
+	{"-le",	INTLE,	BINOP},
+	{"-lt",	INTLT,	BINOP},
+	{"-nt",	FILNT,	BINOP},
+	{"-ot",	FILOT,	BINOP},
+	{"-ef",	FILEQ,	BINOP},
+	{"!",	UNOT,	BUNOP},
+	{"-a",	BAND,	BBINOP},
+	{"-o",	BOR,	BBINOP},
+	{"(",	LPAREN,	PAREN},
+	{")",	RPAREN,	PAREN},
+	{0,	0,	0}
+};
+
+static char **t_wp;
+static struct t_op const *t_wp_op;
+
+static void syntax(const char *, const char *);
+static int oexpr(enum token);
+static int aexpr(enum token);
+static int nexpr(enum token);
+static int primary(enum token);
+static int binop(void);
+static int filstat(char *, enum token);
+static enum token t_lex(char **);
+static int isoperand(char **);
+static int newerf(const char *, const char *);
+static int olderf(const char *, const char *);
+static int equalf(const char *, const char *);
+#ifdef HAVE_FACCESSAT
+static int test_file_access(const char *, int);
+#else
+static int test_access(const struct stat64 *, int);
+#endif
+
+#ifdef HAVE_FACCESSAT
+# ifdef HAVE_TRADITIONAL_FACCESSAT
+static inline int faccessat_confused_about_superuser(void) { return 1; }
+# else
+static inline int faccessat_confused_about_superuser(void) { return 0; }
+# endif
+#endif
+
+static inline intmax_t getn(const char *s)
+{
+	return atomax10(s);
+}
+
+static const struct t_op *getop(const char *s)
+{
+	const struct t_op *op;
+
+	for (op = ops; op->op_text; op++) {
+		if (strcmp(s, op->op_text) == 0)
+			return op;
+	}
+
+	return NULL;
+}
+
+int
+testcmd(int argc, char **argv)
+{
+	const struct t_op *op;
+	enum token n;
+	int res = 1;
+
+	if (*argv[0] == '[') {
+		if (*argv[--argc] != ']')
+			error("missing ]");
+		argv[argc] = NULL;
+	}
+
+	t_wp_op = NULL;
+
+recheck:
+	argv++;
+	argc--;
+
+	if (argc < 1)
+		return res;
+
+	/*
+	 * POSIX prescriptions: he who wrote this deserves the Nobel
+	 * peace prize.
+	 */
+	switch (argc) {
+	case 3:
+		op = getop(argv[1]);
+		if (op && op->op_type == BINOP) {
+			n = OPERAND;
+			goto eval;
+		}
+		/* fall through */
+
+	case 4:
+		if (!strcmp(argv[0], "(") && !strcmp(argv[argc - 1], ")")) {
+			argv[--argc] = NULL;
+			argv++;
+			argc--;
+		} else if (!strcmp(argv[0], "!")) {
+			res = 0;
+			goto recheck;
+		}
+	}
+
+	n = t_lex(argv);
+
+eval:
+	t_wp = argv;
+	res ^= oexpr(n);
+	argv = t_wp;
+
+	if (argv[0] != NULL && argv[1] != NULL)
+		syntax(argv[0], "unexpected operator");
+
+	return res;
+}
+
+static void
+syntax(const char *op, const char *msg)
+{
+	if (op && *op)
+		error("%s: %s", op, msg);
+	else
+		error("%s", msg);
+}
+
+static int
+oexpr(enum token n)
+{
+	int res = 0;
+
+	for (;;) {
+		res |= aexpr(n);
+		n = t_lex(t_wp + 1);
+		if (n != BOR)
+			break;
+		n = t_lex(t_wp += 2);
+	}
+	return res;
+}
+
+static int
+aexpr(enum token n)
+{
+	int res = 1;
+
+	for (;;) {
+		if (!nexpr(n))
+			res = 0;
+		n = t_lex(t_wp + 1);
+		if (n != BAND)
+			break;
+		n = t_lex(t_wp += 2);
+	}
+	return res;
+}
+
+static int
+nexpr(enum token n)
+{
+	if (n != UNOT)
+		return primary(n);
+
+	n = t_lex(t_wp + 1);
+	if (n != EOI)
+		t_wp++;
+	return !nexpr(n);
+}
+
+static int
+primary(enum token n)
+{
+	enum token nn;
+	int res;
+
+	if (n == EOI)
+		return 0;		/* missing expression */
+	if (n == LPAREN) {
+		if ((nn = t_lex(++t_wp)) == RPAREN)
+			return 0;	/* missing expression */
+		res = oexpr(nn);
+		if (t_lex(++t_wp) != RPAREN)
+			syntax(NULL, "closing paren expected");
+		return res;
+	}
+	if (t_wp_op && t_wp_op->op_type == UNOP) {
+		/* unary expression */
+		if (*++t_wp == NULL)
+			syntax(t_wp_op->op_text, "argument expected");
+		switch (n) {
+		case STREZ:
+			return strlen(*t_wp) == 0;
+		case STRNZ:
+			return strlen(*t_wp) != 0;
+		case FILTT:
+			return isatty(getn(*t_wp));
+#ifdef HAVE_FACCESSAT
+		case FILRD:
+			return test_file_access(*t_wp, R_OK);
+		case FILWR:
+			return test_file_access(*t_wp, W_OK);
+		case FILEX:
+			return test_file_access(*t_wp, X_OK);
+#endif
+		default:
+			return filstat(*t_wp, n);
+		}
+	}
+
+	if (t_lex(t_wp + 1), t_wp_op && t_wp_op->op_type == BINOP) {
+		return binop();
+	}
+
+	return strlen(*t_wp) > 0;
+}
+
+static int
+binop(void)
+{
+	const char *opnd1, *opnd2;
+	struct t_op const *op;
+
+	opnd1 = *t_wp;
+	(void) t_lex(++t_wp);
+	op = t_wp_op;
+
+	if ((opnd2 = *++t_wp) == (char *)0)
+		syntax(op->op_text, "argument expected");
+
+	switch (op->op_num) {
+	default:
+#ifdef DEBUG
+		abort();
+		/* NOTREACHED */
+#endif
+	case STREQ:
+		return strcmp(opnd1, opnd2) == 0;
+	case STRNE:
+		return strcmp(opnd1, opnd2) != 0;
+	case STRLT:
+		return strcmp(opnd1, opnd2) < 0;
+	case STRGT:
+		return strcmp(opnd1, opnd2) > 0;
+	case INTEQ:
+		return getn(opnd1) == getn(opnd2);
+	case INTNE:
+		return getn(opnd1) != getn(opnd2);
+	case INTGE:
+		return getn(opnd1) >= getn(opnd2);
+	case INTGT:
+		return getn(opnd1) > getn(opnd2);
+	case INTLE:
+		return getn(opnd1) <= getn(opnd2);
+	case INTLT:
+		return getn(opnd1) < getn(opnd2);
+	case FILNT:
+		return newerf (opnd1, opnd2);
+	case FILOT:
+		return olderf (opnd1, opnd2);
+	case FILEQ:
+		return equalf (opnd1, opnd2);
+	}
+}
+
+static int
+filstat(char *nm, enum token mode)
+{
+	struct stat64 s;
+
+	if (mode == FILSYM ? lstat64(nm, &s) : stat64(nm, &s))
+		return 0;
+
+	switch (mode) {
+#ifndef HAVE_FACCESSAT
+	case FILRD:
+		return test_access(&s, R_OK);
+	case FILWR:
+		return test_access(&s, W_OK);
+	case FILEX:
+		return test_access(&s, X_OK);
+#endif
+	case FILEXIST:
+		return 1;
+	case FILREG:
+		return S_ISREG(s.st_mode);
+	case FILDIR:
+		return S_ISDIR(s.st_mode);
+	case FILCDEV:
+		return S_ISCHR(s.st_mode);
+	case FILBDEV:
+		return S_ISBLK(s.st_mode);
+	case FILFIFO:
+		return S_ISFIFO(s.st_mode);
+	case FILSOCK:
+		return S_ISSOCK(s.st_mode);
+	case FILSYM:
+		return S_ISLNK(s.st_mode);
+	case FILSUID:
+		return (s.st_mode & S_ISUID) != 0;
+	case FILSGID:
+		return (s.st_mode & S_ISGID) != 0;
+	case FILSTCK:
+		return (s.st_mode & S_ISVTX) != 0;
+	case FILGZ:
+		return !!s.st_size;
+	case FILUID:
+		return s.st_uid == geteuid();
+	case FILGID:
+		return s.st_gid == getegid();
+	default:
+		return 1;
+	}
+}
+
+static enum token t_lex(char **tp)
+{
+	struct t_op const *op;
+	char *s = *tp;
+
+	if (s == 0) {
+		t_wp_op = (struct t_op *)0;
+		return EOI;
+	}
+
+	op = getop(s);
+	if (op && !(op->op_type == UNOP && isoperand(tp)) &&
+	    !(op->op_num == LPAREN && !tp[1])) {
+		t_wp_op = op;
+		return op->op_num;
+	}
+
+	t_wp_op = (struct t_op *)0;
+	return OPERAND;
+}
+
+static int isoperand(char **tp)
+{
+	struct t_op const *op;
+	char *s;
+
+	if (!(s = tp[1]))
+		return 1;
+	if (!tp[2])
+		return 0;
+
+	op = getop(s);
+	return op && op->op_type == BINOP;
+}
+
+static int
+newerf (const char *f1, const char *f2)
+{
+	struct stat64 b1, b2;
+
+#ifdef HAVE_ST_MTIM
+	return (stat64(f1, &b1) == 0 &&
+		stat64(f2, &b2) == 0 &&
+		( b1.st_mtim.tv_sec > b2.st_mtim.tv_sec ||
+		 (b1.st_mtim.tv_sec == b2.st_mtim.tv_sec && (b1.st_mtim.tv_nsec > b2.st_mtim.tv_nsec )))
+	);
+#else
+	return (stat64(f1, &b1) == 0 &&
+		stat64(f2, &b2) == 0 &&
+		b1.st_mtime > b2.st_mtime);
+#endif
+}
+
+static int
+olderf (const char *f1, const char *f2)
+{
+	struct stat64 b1, b2;
+
+#ifdef HAVE_ST_MTIM
+	return (stat64(f1, &b1) == 0 &&
+		stat64(f2, &b2) == 0 &&
+		(b1.st_mtim.tv_sec < b2.st_mtim.tv_sec ||
+		 (b1.st_mtim.tv_sec == b2.st_mtim.tv_sec && (b1.st_mtim.tv_nsec < b2.st_mtim.tv_nsec )))
+	);
+#else
+	return (stat64(f1, &b1) == 0 &&
+		stat64(f2, &b2) == 0 &&
+		b1.st_mtime < b2.st_mtime);
+#endif
+}
+
+static int
+equalf (const char *f1, const char *f2)
+{
+	struct stat64 b1, b2;
+
+	return (stat64(f1, &b1) == 0 &&
+		stat64(f2, &b2) == 0 &&
+		b1.st_dev == b2.st_dev &&
+		b1.st_ino == b2.st_ino);
+}
+
+#ifdef HAVE_FACCESSAT
+static int has_exec_bit_set(const char *path)
+{
+	struct stat64 st;
+
+	if (stat64(path, &st))
+		return 0;
+	return st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH);
+}
+
+static int test_file_access(const char *path, int mode)
+{
+	if (faccessat_confused_about_superuser() &&
+	    mode == X_OK && geteuid() == 0 && !has_exec_bit_set(path))
+		return 0;
+	return !faccessat(AT_FDCWD, path, mode, AT_EACCESS);
+}
+#else	/* HAVE_FACCESSAT */
+/*
+ * The manual, and IEEE POSIX 1003.2, suggests this should check the mode bits,
+ * not use access():
+ *
+ *	True shall indicate only that the write flag is on.  The file is not
+ *	writable on a read-only file system even if this test indicates true.
+ *
+ * Unfortunately IEEE POSIX 1003.1-2001, as quoted in SuSv3, says only:
+ *
+ *	True shall indicate that permission to read from file will be granted,
+ *	as defined in "File Read, Write, and Creation".
+ *
+ * and that section says:
+ *
+ *	When a file is to be read or written, the file shall be opened with an
+ *	access mode corresponding to the operation to be performed.  If file
+ *	access permissions deny access, the requested operation shall fail.
+ *
+ * and of course access permissions are described as one might expect:
+ *
+ *     * If a process has the appropriate privilege:
+ *
+ *        * If read, write, or directory search permission is requested,
+ *          access shall be granted.
+ *
+ *        * If execute permission is requested, access shall be granted if
+ *          execute permission is granted to at least one user by the file
+ *          permission bits or by an alternate access control mechanism;
+ *          otherwise, access shall be denied.
+ *
+ *   * Otherwise:
+ *
+ *        * The file permission bits of a file contain read, write, and
+ *          execute/search permissions for the file owner class, file group
+ *          class, and file other class.
+ *
+ *        * Access shall be granted if an alternate access control mechanism
+ *          is not enabled and the requested access permission bit is set for
+ *          the class (file owner class, file group class, or file other class)
+ *          to which the process belongs, or if an alternate access control
+ *          mechanism is enabled and it allows the requested access; otherwise,
+ *          access shall be denied.
+ *
+ * and when I first read this I thought:  surely we can't go about using
+ * open(O_WRONLY) to try this test!  However the POSIX 1003.1-2001 Rationale
+ * section for test does in fact say:
+ *
+ *	On historical BSD systems, test -w directory always returned false
+ *	because test tried to open the directory for writing, which always
+ *	fails.
+ *
+ * and indeed this is in fact true for Seventh Edition UNIX, UNIX 32V, and UNIX
+ * System III, and thus presumably also for BSD up to and including 4.3.
+ *
+ * Secondly I remembered why using open() and/or access() are bogus.  They
+ * don't work right for detecting read and write permissions bits when called
+ * by root.
+ *
+ * Interestingly the 'test' in 4.4BSD was closer to correct (as per
+ * 1003.2-1992) and it was implemented efficiently with stat() instead of
+ * open().
+ *
+ * This was apparently broken in NetBSD around about 1994/06/30 when the old
+ * 4.4BSD implementation was replaced with a (arguably much better coded)
+ * implementation derived from pdksh.
+ *
+ * Note that modern pdksh is yet different again, but still not correct, at
+ * least not w.r.t. 1003.2-1992.
+ *
+ * As I think more about it and read more of the related IEEE docs I don't like
+ * that wording about 'test -r' and 'test -w' in 1003.1-2001 at all.  I very
+ * much prefer the original wording in 1003.2-1992.  It is much more useful,
+ * and so that's what I've implemented.
+ *
+ * (Note that a strictly conforming implementation of 1003.1-2001 is in fact
+ * totally useless for the case in question since its 'test -w' and 'test -r'
+ * can never fail for root for any existing files, i.e. files for which 'test
+ * -e' succeeds.)
+ *
+ * The rationale for 1003.1-2001 suggests that the wording was "clarified" in
+ * 1003.1-2001 to align with the 1003.2b draft.  1003.2b Draft 12 (July 1999),
+ * which is the latest copy I have, does carry the same suggested wording as is
+ * in 1003.1-2001, with its rationale saying:
+ *
+ * 	This change is a clarification and is the result of interpretation
+ * 	request PASC 1003.2-92 #23 submitted for IEEE Std 1003.2-1992.
+ *
+ * That interpretation can be found here:
+ *
+ *   http://www.pasc.org/interps/unofficial/db/p1003.2/pasc-1003.2-23.html
+ *
+ * Not terribly helpful, unfortunately.  I wonder who that fence sitter was.
+ *
+ * Worse, IMVNSHO, I think the authors of 1003.2b-D12 have mis-interpreted the
+ * PASC interpretation and appear to be gone against at least one widely used
+ * implementation (namely 4.4BSD).  The problem is that for file access by root
+ * this means that if test '-r' and '-w' are to behave as if open() were called
+ * then there's no way for a shell script running as root to check if a file
+ * has certain access bits set other than by the grotty means of interpreting
+ * the output of 'ls -l'.  This was widely considered to be a bug in V7's
+ * "test" and is, I believe, one of the reasons why direct use of access() was
+ * avoided in some more recent implementations!
+ *
+ * I have always interpreted '-r' to match '-w' and '-x' as per the original
+ * wording in 1003.2-1992, not the other way around.  I think 1003.2b goes much
+ * too far the wrong way without any valid rationale and that it's best if we
+ * stick with 1003.2-1992 and test the flags, and not mimic the behaviour of
+ * open() since we already know very well how it will work -- existance of the
+ * file is all that matters to open() for root.
+ *
+ * Unfortunately the SVID is no help at all (which is, I guess, partly why
+ * we're in this mess in the first place :-).
+ *
+ * The SysV implementation (at least in the 'test' builtin in /bin/sh) does use
+ * access(name, 2) even though it also goes to much greater lengths for '-x'
+ * matching the 1003.2-1992 definition (which is no doubt where that definition
+ * came from).
+ *
+ * The ksh93 implementation uses access() for '-r' and '-w' if
+ * (euid==uid&&egid==gid), but uses st_mode for '-x' iff running as root.
+ * i.e. it does strictly conform to 1003.1-2001 (and presumably 1003.2b).
+ */
+static int test_access(const struct stat64 *sp, int stmode)
+{
+	gid_t *groups;
+	register int n;
+	uid_t euid;
+	int maxgroups;
+
+	/*
+	 * I suppose we could use access() if not running as root and if we are
+	 * running with ((euid == uid) && (egid == gid)), but we've already
+	 * done the stat() so we might as well just test the permissions
+	 * directly instead of asking the kernel to do it....
+	 */
+	euid = geteuid();
+	if (euid == 0) {
+		if (stmode != X_OK)
+			return 1;
+
+		/* any bit is good enough */
+		stmode = (stmode << 6) | (stmode << 3) | stmode;
+	} else if (sp->st_uid == euid)
+		stmode <<= 6;
+	else if (sp->st_gid == getegid())
+		stmode <<= 3;
+	else {
+		/* XXX stolen almost verbatim from ksh93.... */
+		/* on some systems you can be in several groups */
+		maxgroups = getgroups(0, NULL);
+		groups = stalloc(maxgroups * sizeof(*groups));
+		n = getgroups(maxgroups, groups);
+		while (--n >= 0) {
+			if (groups[n] == sp->st_gid) {
+				stmode <<= 3;
+				break;
+			}
+		}
+	}
+
+	return sp->st_mode & stmode;
+}
+#endif	/* HAVE_FACCESSAT */
diff --git a/src/bltin/times.c b/src/bltin/times.c
new file mode 100644
index 00000000..1166a68e
--- /dev/null
+++ b/src/bltin/times.c
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 1999 Herbert Xu <herbert@gondor.apana.org.au>
+ * This file contains code for the times builtin.
+ */
+
+#include <sys/times.h>
+#include <unistd.h>
+#ifdef USE_GLIBC_STDIO
+#include <stdio.h>
+#else
+#include "bltin.h"
+#endif
+#include "system.h"
+
+int timescmd() {
+	struct tms buf;
+	long int clk_tck = sysconf(_SC_CLK_TCK);
+	int mutime, mstime, mcutime, mcstime;
+	double utime, stime, cutime, cstime;
+
+	times(&buf);
+
+	utime = (double)buf.tms_utime / clk_tck;
+	mutime = utime / 60;
+	utime -= mutime * 60.0;
+
+	stime = (double)buf.tms_stime / clk_tck;
+	mstime = stime / 60;
+	stime -= mstime * 60.0;
+
+	cutime = (double)buf.tms_cutime / clk_tck;
+	mcutime = cutime / 60;
+	cutime -= mcutime * 60.0;
+
+	cstime = (double)buf.tms_cstime / clk_tck;
+	mcstime = cstime / 60;
+	cstime -= mcstime * 60.0;
+
+	printf("%dm%fs %dm%fs\n%dm%fs %dm%fs\n", mutime, utime, mstime, stime,
+	       mcutime, cutime, mcstime, cstime);
+	return 0;
+}
diff --git a/src/builtins.def.in b/src/builtins.def.in
new file mode 100644
index 00000000..95e420cc
--- /dev/null
+++ b/src/builtins.def.in
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)builtins.def	8.4 (Berkeley) 5/4/95
+ */
+
+/*
+ * This file lists all the builtin commands.  The first column is the name
+ * of a C routine.
+ * The -a flag specifies that this is a posix 'assignment builtin' command.
+ * The -s flag specifies that this is a posix 'special builtin' command.
+ * The -u flag specifies that this is a posix 'standard utility'.
+ * The -n flag specifies that this command has a special entry point.
+ * The rest of the line specifies the command name or names used to run
+ * the command.
+ */
+
+#ifndef JOBS
+#define JOBS 1
+#endif
+
+#if JOBS
+bgcmd		-u bg
+fgcmd		-u fg
+#endif
+
+#ifndef SMALL
+histcmd		-u fc
+#endif
+
+breakcmd	-s break -s continue
+cdcmd		-u cd chdir
+commandcmd	-u command
+dotcmd		-s .
+echocmd		echo
+evalcmd		-ns eval
+execcmd		-s exec
+exitcmd		-s exit
+exportcmd	-as export -as readonly
+falsecmd	-u false
+getoptscmd	-u getopts
+hashcmd		-u hash
+jobscmd		-u jobs
+localcmd	-as local
+printfcmd	printf
+pwdcmd		-u pwd
+readcmd		-u read
+returncmd	-s return
+setcmd		-s set
+shiftcmd	-s shift
+timescmd	-s times
+trapcmd		-s trap
+truecmd		-s : -u true
+typecmd		-u type
+umaskcmd	-u umask
+unaliascmd	-u unalias
+unsetcmd	-s unset
+waitcmd		-u wait
+aliascmd	-au alias
+#ifdef HAVE_GETRLIMIT
+ulimitcmd	-u ulimit
+#endif
+testcmd		test [
+killcmd		-u kill
diff --git a/src/cd.c b/src/cd.c
new file mode 100644
index 00000000..1ef1dc56
--- /dev/null
+++ b/src/cd.c
@@ -0,0 +1,332 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
+#ifdef __CYGWIN__
+#include <sys/cygwin.h>
+#endif
+
+/*
+ * The cd and pwd commands.
+ */
+
+#include "shell.h"
+#include "var.h"
+#include "nodes.h"	/* for jobs.h */
+#include "jobs.h"
+#include "options.h"
+#include "output.h"
+#include "memalloc.h"
+#include "error.h"
+#include "exec.h"
+#include "redir.h"
+#include "main.h"
+#include "mystring.h"
+#include "show.h"
+#include "cd.h"
+
+#define CD_PHYSICAL 1
+#define CD_PRINT 2
+
+STATIC int docd(const char *, int);
+STATIC const char *updatepwd(const char *);
+STATIC char *getpwd(void);
+STATIC int cdopt(void);
+
+STATIC char *curdir = nullstr;		/* current working directory */
+STATIC char *physdir = nullstr;		/* physical working directory */
+
+STATIC int
+cdopt()
+{
+	int flags = 0;
+	int i, j;
+
+	j = 'L';
+	while ((i = nextopt("LP"))) {
+		if (i != j) {
+			flags ^= CD_PHYSICAL;
+			j = i;
+		}
+	}
+
+	return flags;
+}
+
+int
+cdcmd(int argc, char **argv)
+{
+	const char *dest;
+	const char *path;
+	const char *p;
+	char c;
+	struct stat64 statb;
+	int flags;
+	int len;
+
+	flags = cdopt();
+	dest = *argptr;
+	if (!dest)
+		dest = bltinlookup(homestr);
+	else if (dest[0] == '-' && dest[1] == '\0') {
+		dest = bltinlookup("OLDPWD");
+		flags |= CD_PRINT;
+	}
+	if (!dest)
+		dest = nullstr;
+	if (*dest == '/')
+		goto step6;
+	if (*dest == '.') {
+		c = dest[1];
+dotdot:
+		switch (c) {
+		case '\0':
+		case '/':
+			goto step6;
+		case '.':
+			c = dest[2];
+			if (c != '.')
+				goto dotdot;
+		}
+	}
+	if (!*dest)
+		dest = ".";
+	path = bltinlookup("CDPATH");
+	while (p = path, (len = padvance_magic(&path, dest, 0)) >= 0) {
+		c = *p;
+		p = stalloc(len);
+
+		if (stat64(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) {
+			if (c && c != ':')
+				flags |= CD_PRINT;
+docd:
+			if (!docd(p, flags))
+				goto out;
+			goto err;
+		}
+	}
+
+step6:
+	p = dest;
+	goto docd;
+
+err:
+	sh_error("can't cd to %s", dest);
+	/* NOTREACHED */
+out:
+	if (flags & CD_PRINT)
+		out1fmt(snlfmt, curdir);
+	return 0;
+}
+
+
+/*
+ * Actually do the chdir.  We also call hashcd to let the routines in exec.c
+ * know that the current directory has changed.
+ */
+
+STATIC int
+docd(const char *dest, int flags)
+{
+	const char *dir = 0;
+	int err;
+
+	TRACE(("docd(\"%s\", %d) called\n", dest, flags));
+
+	INTOFF;
+	if (!(flags & CD_PHYSICAL)) {
+		dir = updatepwd(dest);
+		if (dir)
+			dest = dir;
+	}
+	err = chdir(dest);
+	if (err)
+		goto out;
+	setpwd(dir, 1);
+	hashcd();
+out:
+	INTON;
+	return err;
+}
+
+
+/*
+ * Update curdir (the name of the current directory) in response to a
+ * cd command.
+ */
+
+STATIC const char *
+updatepwd(const char *dir)
+{
+	char *new;
+	char *p;
+	char *cdcomppath;
+	const char *lim;
+
+#ifdef __CYGWIN__
+	/* On cygwin, thanks to drive letters, some absolute paths do
+	   not begin with slash; but cygwin includes a function that
+	   forces normalization to the posix form */
+	char pathbuf[PATH_MAX];
+	if (cygwin_conv_path(CCP_WIN_A_TO_POSIX | CCP_RELATIVE, dir, pathbuf,
+			     sizeof(pathbuf)) < 0)
+		sh_error("can't normalize %s", dir);
+	dir = pathbuf;
+#endif
+
+	cdcomppath = sstrdup(dir);
+	STARTSTACKSTR(new);
+	if (*dir != '/') {
+		if (curdir == nullstr)
+			return 0;
+		new = stputs(curdir, new);
+	}
+	new = makestrspace(strlen(dir) + 2, new);
+	lim = stackblock() + 1;
+	if (*dir != '/') {
+		if (new[-1] != '/')
+			USTPUTC('/', new);
+		if (new > lim && *lim == '/')
+			lim++;
+	} else {
+		USTPUTC('/', new);
+		cdcomppath++;
+		if (dir[1] == '/' && dir[2] != '/') {
+			USTPUTC('/', new);
+			cdcomppath++;
+			lim++;
+		}
+	}
+	p = strtok(cdcomppath, "/");
+	while (p) {
+		switch(*p) {
+		case '.':
+			if (p[1] == '.' && p[2] == '\0') {
+				while (new > lim) {
+					STUNPUTC(new);
+					if (new[-1] == '/')
+						break;
+				}
+				break;
+			} else if (p[1] == '\0')
+				break;
+			/* fall through */
+		default:
+			new = stputs(p, new);
+			USTPUTC('/', new);
+		}
+		p = strtok(0, "/");
+	}
+	if (new > lim)
+		STUNPUTC(new);
+	*new = 0;
+	return stackblock();
+}
+
+
+/*
+ * Find out what the current directory is. If we already know the current
+ * directory, this routine returns immediately.
+ */
+inline
+STATIC char *
+getpwd()
+{
+#ifdef __GLIBC__
+	char *dir = getcwd(0, 0);
+
+	if (dir)
+		return dir;
+#else
+	char buf[PATH_MAX];
+
+	if (getcwd(buf, sizeof(buf)))
+		return savestr(buf);
+#endif
+
+	sh_warnx("getcwd() failed: %s", strerror(errno));
+	return nullstr;
+}
+
+int
+pwdcmd(int argc, char **argv)
+{
+	int flags;
+	const char *dir = curdir;
+
+	flags = cdopt();
+	if (flags) {
+		if (physdir == nullstr)
+			setpwd(dir, 0);
+		dir = physdir;
+	}
+	out1fmt(snlfmt, dir);
+	return 0;
+}
+
+void
+setpwd(const char *val, int setold)
+{
+	char *oldcur, *dir;
+
+	oldcur = dir = curdir;
+
+	if (setold) {
+		setvar("OLDPWD", oldcur, VEXPORT);
+	}
+	INTOFF;
+	if (physdir != nullstr) {
+		if (physdir != oldcur)
+			free(physdir);
+		physdir = nullstr;
+	}
+	if (oldcur == val || !val) {
+		char *s = getpwd();
+		physdir = s;
+		if (!val)
+			dir = s;
+	} else
+		dir = savestr(val);
+	if (oldcur != dir && oldcur != nullstr) {
+		free(oldcur);
+	}
+	curdir = dir;
+	INTON;
+	setvar("PWD", dir, VEXPORT);
+}
diff --git a/src/cd.h b/src/cd.h
new file mode 100644
index 00000000..87631619
--- /dev/null
+++ b/src/cd.h
@@ -0,0 +1,35 @@
+/*-
+ * Copyright (c) 1995
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+int	cdcmd(int, char **);
+int	pwdcmd(int, char **);
+void	setpwd(const char *, int);
diff --git a/src/dash.1 b/src/dash.1
new file mode 100644
index 00000000..32f6ac0d
--- /dev/null
+++ b/src/dash.1
@@ -0,0 +1,2357 @@
+.\" Copyright (c) 1991, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\" Copyright (c) 1997-2005
+.\"	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" Kenneth Almquist.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)sh.1	8.6 (Berkeley) 5/4/95
+.\"
+.Dd January 19, 2003
+.Os
+.Dt DASH 1
+.Sh NAME
+.Nm dash
+.Nd command interpreter (shell)
+.Sh SYNOPSIS
+.Nm
+.Bk -words
+.Op Fl aCefnuvxIimqVEb
+.Op Cm +aCefnuvxIimqVEb
+.Ek
+.Bk -words
+.Op Fl o Ar option_name
+.Op Cm +o Ar option_name
+.Ek
+.Bk -words
+.Op Ar command_file Oo Ar argument ... Oc
+.Ek
+.Nm
+.Fl c
+.Bk -words
+.Op Fl aCefnuvxIimqVEb
+.Op Cm +aCefnuvxIimqVEb
+.Ek
+.Bk -words
+.Op Fl o Ar option_name
+.Op Cm +o Ar option_name
+.Ek
+.Bk -words
+.Ar command_string
+.Op Ar command_name Oo Ar argument ... Oc
+.Ek
+.Nm
+.Fl s
+.Bk -words
+.Op Fl aCefnuvxIimqVEb
+.Op Cm +aCefnuvxIimqVEb
+.Ek
+.Bk -words
+.Op Fl o Ar option_name
+.Op Cm +o Ar option_name
+.Ek
+.Bk -words
+.Op Ar argument ...
+.Ek
+.Sh DESCRIPTION
+.Nm
+is the standard command interpreter for the system.
+The current version of
+.Nm
+is in the process of being changed to conform with the
+.Tn POSIX
+1003.2 and 1003.2a specifications for the shell.
+This version has many
+features which make it appear similar in some respects to the Korn shell,
+but it is not a Korn shell clone (see
+.Xr ksh 1 ) .
+Only features designated by
+.Tn POSIX ,
+plus a few Berkeley extensions, are being incorporated into this shell.
+This man page is not intended
+to be a tutorial or a complete specification of the shell.
+.Ss Overview
+The shell is a command that reads lines from either a file or the
+terminal, interprets them, and generally executes other commands.
+It is the program that is running when a user logs into the system
+(although a user can select a different shell with the
+.Xr chsh 1
+command).
+The shell implements a language that has flow control
+constructs, a macro facility that provides a variety of features in
+addition to data storage, along with built in history and line editing
+capabilities.
+It incorporates many features to aid interactive use and
+has the advantage that the interpretative language is common to both
+interactive and non-interactive use (shell scripts).
+That is, commands
+can be typed directly to the running shell or can be put into a file and
+the file can be executed directly by the shell.
+.Ss Invocation
+If no args are present and if the standard input of the shell
+is connected to a terminal (or if the
+.Fl i
+flag is set),
+and the
+.Fl c
+option is not present, the shell is considered an interactive shell.
+An interactive shell generally prompts before each command and handles
+programming and command errors differently (as described below).
+When first starting,
+the shell inspects argument 0, and if it begins with a dash
+.Sq - ,
+the shell is also considered
+a login shell.
+This is normally done automatically by the system
+when the user first logs in.
+A login shell first reads commands
+from the files
+.Pa /etc/profile
+and
+.Pa .profile
+if they exist.
+If the environment variable
+.Ev ENV
+is set on entry to an interactive shell, or is set in the
+.Pa .profile
+of a login shell, the shell next reads
+commands from the file named in
+.Ev ENV .
+Therefore, a user should place commands that are to be executed only at
+login time in the
+.Pa .profile
+file, and commands that are executed for every interactive shell inside the
+.Ev ENV
+file.
+To set the
+.Ev ENV
+variable to some file, place the following line in your
+.Pa .profile
+of your home directory
+.Pp
+.Dl ENV=$HOME/.shinit; export ENV
+.Pp
+substituting for
+.Dq .shinit
+any filename you wish.
+.Pp
+If command line arguments besides the options have been specified, then
+the shell treats the first argument as the name of a file from which to
+read commands (a shell script), and the remaining arguments are set as the
+positional parameters of the shell ($1, $2, etc).
+Otherwise, the shell
+reads commands from its standard input.
+.Ss Argument List Processing
+All of the single letter options that have a corresponding name can be
+used as an argument to the
+.Fl o
+option.
+The set
+.Fl o
+name is provided next to the single letter option in
+the description below.
+Specifying a dash
+.Dq -
+turns the option on, while using a plus
+.Dq +
+disables the option.
+The following options can be set from the command line or
+with the
+.Ic set
+builtin (described later).
+.Bl -tag -width aaaallexportfoo -offset indent
+.It Fl a Em allexport
+Export all variables assigned to.
+.It Fl c
+Read commands from the
+.Ar command_string
+operand instead of from the standard input.
+Special parameter 0 will be set from the
+.Ar command_name
+operand and the positional parameters ($1, $2, etc.)
+set from the remaining argument operands.
+.It Fl C Em noclobber
+Don't overwrite existing files with
+.Dq \*[Gt] .
+.It Fl e Em errexit
+If not interactive, exit immediately if any untested command fails.
+The exit status of a command is considered to be
+explicitly tested if the command is used to control an
+.Ic if ,
+.Ic elif ,
+.Ic while ,
+or
+.Ic until ;
+or if the command is the left hand operand of an
+.Dq &&
+or
+.Dq ||
+operator.
+.It Fl f Em noglob
+Disable pathname expansion.
+.It Fl n Em noexec
+If not interactive, read commands but do not execute them.
+This is useful for checking the syntax of shell scripts.
+.It Fl u Em nounset
+Write a message to standard error when attempting to expand a variable
+that is not set, and if the shell is not interactive, exit immediately.
+.It Fl v Em verbose
+The shell writes its input to standard error as it is read.
+Useful for debugging.
+.It Fl x Em xtrace
+Write each command to standard error (preceded by a
+.Sq +\  )
+before it is executed.
+Useful for debugging.
+.It Fl I Em ignoreeof
+Ignore EOF's from input when interactive.
+.It Fl i Em interactive
+Force the shell to behave interactively.
+.It Fl l
+Make dash act as if it had been invoked as a login shell.
+.It Fl m Em monitor
+Turn on job control (set automatically when interactive).
+.It Fl s Em stdin
+Read commands from standard input (set automatically if no file arguments
+are present).
+This option has no effect when set after the shell has
+already started running (i.e. with
+.Ic set ) .
+.It Fl V Em vi
+Enable the built-in
+.Xr vi 1
+command line editor (disables
+.Fl E
+if it has been set).
+.It Fl E Em emacs
+Enable the built-in
+.Xr emacs 1
+command line editor (disables
+.Fl V
+if it has been set).
+.It Fl b Em notify
+Enable asynchronous notification of background job completion.
+(UNIMPLEMENTED for 4.4alpha)
+.El
+.Ss Lexical Structure
+The shell reads input in terms of lines from a file and breaks it up into
+words at whitespace (blanks and tabs), and at certain sequences of
+characters that are special to the shell called
+.Dq operators .
+There are two types of operators: control operators and redirection
+operators (their meaning is discussed later).
+Following is a list of operators:
+.Bl -ohang -offset indent
+.It "Control operators:"
+.Dl &  &&  \&(  \&)  \&;  ;; | || \*[Lt]newline\*[Gt]
+.It "Redirection operators:"
+.Dl \*[Lt]  \*[Gt]  \*[Gt]|  \*[Lt]\*[Lt]  \*[Gt]\*[Gt]  \*[Lt]&  \*[Gt]&  \*[Lt]\*[Lt]-  \*[Lt]\*[Gt]
+.El
+.Ss Quoting
+Quoting is used to remove the special meaning of certain characters or
+words to the shell, such as operators, whitespace, or keywords.
+There are three types of quoting: matched single quotes,
+matched double quotes, and backslash.
+.Ss Backslash
+A backslash preserves the literal meaning of the following
+character, with the exception of
+.Aq newline .
+A backslash preceding a
+.Aq newline
+is treated as a line continuation.
+.Ss Single Quotes
+Enclosing characters in single quotes preserves the literal meaning of all
+the characters (except single quotes, making it impossible to put
+single-quotes in a single-quoted string).
+.Ss Double Quotes
+Enclosing characters within double quotes preserves the literal
+meaning of all characters except dollarsign
+.Pq $ ,
+backquote
+.Pq ` ,
+and backslash
+.Pq \e .
+The backslash inside double quotes is historically weird, and serves to
+quote only the following characters:
+.Dl $  `  \*q  \e  \*[Lt]newline\*[Gt] .
+Otherwise it remains literal.
+.Ss Reserved Words
+Reserved words are words that have special meaning to the
+shell and are recognized at the beginning of a line and
+after a control operator.
+The following are reserved words:
+.Bl -column while while while while while -offset indent
+.It ! Ta elif Ta fi Ta while Ta case
+.It else Ta for Ta then Ta { Ta }
+.It do Ta done Ta until Ta if Ta esac
+.El
+.Pp
+Their meaning is discussed later.
+.Ss Aliases
+An alias is a name and corresponding value set using the
+.Xr alias 1
+builtin command.
+Whenever a reserved word may occur (see above),
+and after checking for reserved words, the shell
+checks the word to see if it matches an alias.
+If it does, it replaces it in the input stream with its value.
+For example, if there is an alias called
+.Dq lf
+with the value
+.Dq "ls -F" ,
+then the input:
+.Pp
+.Dl lf foobar Aq return
+.Pp
+would become
+.Pp
+.Dl ls -F foobar Aq return
+.Pp
+Aliases provide a convenient way for naive users to create shorthands for
+commands without having to learn how to create functions with arguments.
+They can also be used to create lexically obscure code.
+This use is discouraged.
+.Ss Commands
+The shell interprets the words it reads according to a language, the
+specification of which is outside the scope of this man page (refer to the
+BNF in the
+.Tn POSIX
+1003.2 document).
+Essentially though, a line is read and if the first
+word of the line (or after a control operator) is not a reserved word,
+then the shell has recognized a simple command.
+Otherwise, a complex
+command or some other special construct may have been recognized.
+.Ss Simple Commands
+If a simple command has been recognized, the shell performs
+the following actions:
+.Bl -enum -offset indent
+.It
+Leading words of the form
+.Dq name=value
+are stripped off and assigned to the environment of the simple command.
+Redirection operators and their arguments (as described below) are
+stripped off and saved for processing.
+.It
+The remaining words are expanded as described in
+the section called
+.Dq Expansions ,
+and the first remaining word is considered the command name and the
+command is located.
+The remaining words are considered the arguments of the command.
+If no command name resulted, then the
+.Dq name=value
+variable assignments recognized in item 1 affect the current shell.
+.It
+Redirections are performed as described in the next section.
+.El
+.Ss Redirections
+Redirections are used to change where a command reads its input or sends
+its output.
+In general, redirections open, close, or duplicate an
+existing reference to a file.
+The overall format used for redirection is:
+.Pp
+.Dl [n] Va redir-op Ar file
+.Pp
+where
+.Va redir-op
+is one of the redirection operators mentioned previously.
+Following is a list of the possible redirections.
+The
+.Bq n
+is an optional number between 0 and 9, as in
+.Sq 3
+(not
+.Sq Bq 3 ) ,
+that refers to a file descriptor.
+.Bl -tag -width aaabsfiles -offset indent
+.It [n] Ns \*[Gt] file
+Redirect standard output (or n) to file.
+.It [n] Ns \*[Gt]| file
+Same, but override the
+.Fl C
+option.
+.It [n] Ns \*[Gt]\*[Gt] file
+Append standard output (or n) to file.
+.It [n] Ns \*[Lt] file
+Redirect standard input (or n) from file.
+.It [n1] Ns \*[Lt]& Ns n2
+Copy file descriptor n2 as stdout (or fd n1).
+fd n2.
+.It [n] Ns \*[Lt]&-
+Close standard input (or n).
+.It [n1] Ns \*[Gt]& Ns n2
+Copy file descriptor n2 as stdin (or fd n1).
+fd n2.
+.It [n] Ns \*[Gt]&-
+Close standard output (or n).
+.It [n] Ns \*[Lt]\*[Gt] file
+Open file for reading and writing on standard input (or n).
+.El
+.Pp
+The following redirection is often called a
+.Dq here-document .
+.Bl -item -offset indent
+.It
+.Li [n]\*[Lt]\*[Lt] delimiter
+.Dl here-doc-text ...
+.Li delimiter
+.El
+.Pp
+All the text on successive lines up to the delimiter is saved away and
+made available to the command on standard input, or file descriptor n if
+it is specified.
+If the delimiter as specified on the initial line is
+quoted, then the here-doc-text is treated literally, otherwise the text is
+subjected to parameter expansion, command substitution, and arithmetic
+expansion (as described in the section on
+.Dq Expansions ) .
+If the operator is
+.Dq \*[Lt]\*[Lt]-
+instead of
+.Dq \*[Lt]\*[Lt] ,
+then leading tabs in the here-doc-text are stripped.
+.Ss Search and Execution
+There are three types of commands: shell functions, builtin commands, and
+normal programs -- and the command is searched for (by name) in that order.
+They each are executed in a different way.
+.Pp
+When a shell function is executed, all of the shell positional parameters
+(except $0, which remains unchanged) are set to the arguments of the shell
+function.
+The variables which are explicitly placed in the environment of
+the command (by placing assignments to them before the function name) are
+made local to the function and are set to the values given.
+Then the command given in the function definition is executed.
+The positional parameters are restored to their original values
+when the command completes.
+This all occurs within the current shell.
+.Pp
+Shell builtins are executed internally to the shell, without spawning a
+new process.
+.Pp
+Otherwise, if the command name doesn't match a function or builtin, the
+command is searched for as a normal program in the file system (as
+described in the next section).
+When a normal program is executed, the shell runs the program,
+passing the arguments and the environment to the program.
+If the program is not a normal executable file (i.e., if it does
+not begin with the "magic number" whose
+.Tn ASCII
+representation is "#!", so
+.Xr execve 2
+returns
+.Er ENOEXEC
+then) the shell will interpret the program in a subshell.
+The child shell will reinitialize itself in this case,
+so that the effect will be as if a
+new shell had been invoked to handle the ad-hoc shell script, except that
+the location of hashed commands located in the parent shell will be
+remembered by the child.
+.Pp
+Note that previous versions of this document and the source code itself
+misleadingly and sporadically refer to a shell script without a magic
+number as a "shell procedure".
+.Ss Path Search
+When locating a command, the shell first looks to see if it has a shell
+function by that name.
+Then it looks for a builtin command by that name.
+If a builtin command is not found, one of two things happen:
+.Bl -enum
+.It
+Command names containing a slash are simply executed without performing
+any searches.
+.It
+The shell searches each entry in
+.Ev PATH
+in turn for the command.
+The value of the
+.Ev PATH
+variable should be a series of entries separated by colons.
+Each entry consists of a directory name.
+The current directory may be indicated
+implicitly by an empty directory name, or explicitly by a single period.
+.El
+.Ss Command Exit Status
+Each command has an exit status that can influence the behaviour
+of other shell commands.
+The paradigm is that a command exits
+with zero for normal or success, and non-zero for failure,
+error, or a false indication.
+The man page for each command
+should indicate the various exit codes and what they mean.
+Additionally, the builtin commands return exit codes, as does
+an executed shell function.
+.Pp
+If a command consists entirely of variable assignments then the
+exit status of the command is that of the last command substitution
+if any, otherwise 0.
+.Ss Complex Commands
+Complex commands are combinations of simple commands with control
+operators or reserved words, together creating a larger complex command.
+More generally, a command is one of the following:
+.Bl -bullet
+.It
+simple command
+.It
+pipeline
+.It
+list or compound-list
+.It
+compound command
+.It
+function definition
+.El
+.Pp
+Unless otherwise stated, the exit status of a command is that of the last
+simple command executed by the command.
+.Ss Pipelines
+A pipeline is a sequence of one or more commands separated
+by the control operator |.
+The standard output of all but
+the last command is connected to the standard input
+of the next command.
+The standard output of the last
+command is inherited from the shell, as usual.
+.Pp
+The format for a pipeline is:
+.Pp
+.Dl [!] command1 [ | command2 ...]
+.Pp
+The standard output of command1 is connected to the standard input of
+command2.
+The standard input, standard output, or both of a command is
+considered to be assigned by the pipeline before any redirection specified
+by redirection operators that are part of the command.
+.Pp
+If the pipeline is not in the background (discussed later), the shell
+waits for all commands to complete.
+.Pp
+If the reserved word ! does not precede the pipeline, the exit status is
+the exit status of the last command specified in the pipeline.
+Otherwise, the exit status is the logical NOT of the exit status of the
+last command.
+That is, if the last command returns zero, the exit status
+is 1; if the last command returns greater than zero, the exit status is
+zero.
+.Pp
+Because pipeline assignment of standard input or standard output or both
+takes place before redirection, it can be modified by redirection.
+For example:
+.Pp
+.Dl $ command1 2\*[Gt]&1 | command2
+.Pp
+sends both the standard output and standard error of command1
+to the standard input of command2.
+.Pp
+A ; or
+.Aq newline
+terminator causes the preceding AND-OR-list (described
+next) to be executed sequentially; a & causes asynchronous execution of
+the preceding AND-OR-list.
+.Pp
+Note that unlike some other shells, each process in the pipeline is a
+child of the invoking shell (unless it is a shell builtin, in which case
+it executes in the current shell -- but any effect it has on the
+environment is wiped).
+.Ss Background Commands -- &
+If a command is terminated by the control operator ampersand (&), the
+shell executes the command asynchronously -- that is, the shell does not
+wait for the command to finish before executing the next command.
+.Pp
+The format for running a command in background is:
+.Pp
+.Dl command1 & [command2 & ...]
+.Pp
+If the shell is not interactive, the standard input of an asynchronous
+command is set to
+.Pa /dev/null .
+.Ss Lists -- Generally Speaking
+A list is a sequence of zero or more commands separated by newlines,
+semicolons, or ampersands, and optionally terminated by one of these three
+characters.
+The commands in a list are executed in the order they are written.
+If command is followed by an ampersand, the shell starts the
+command and immediately proceeds onto the next command; otherwise it waits
+for the command to terminate before proceeding to the next one.
+.Ss Short-Circuit List Operators
+.Dq &&
+and
+.Dq ||
+are AND-OR list operators.
+.Dq &&
+executes the first command, and then executes the second command if and only
+if the exit status of the first command is zero.
+.Dq ||
+is similar, but executes the second command if and only if the exit status
+of the first command is nonzero.
+.Dq &&
+and
+.Dq ||
+both have the same priority.
+.Ss Flow-Control Constructs -- if, while, for, case
+The syntax of the if command is
+.Bd -literal -offset indent
+if list
+then list
+[ elif list
+then    list ] ...
+[ else list ]
+fi
+.Ed
+.Pp
+The syntax of the while command is
+.Bd -literal -offset indent
+while list
+do   list
+done
+.Ed
+.Pp
+The two lists are executed repeatedly while the exit status of the
+first list is zero.
+The until command is similar, but has the word
+until in place of while, which causes it to
+repeat until the exit status of the first list is zero.
+.Pp
+The syntax of the for command is
+.Bd -literal -offset indent
+for variable [ in [ word ... ] ]
+do   list
+done
+.Ed
+.Pp
+The words following
+.Pa in
+are expanded, and then the list is executed repeatedly with the
+variable set to each word in turn.
+Omitting in word ... is equivalent to in "$@".
+.Pp
+The syntax of the break and continue command is
+.Bd -literal -offset indent
+break [ num ]
+continue [ num ]
+.Ed
+.Pp
+Break terminates the num innermost for or while loops.
+Continue continues with the next iteration of the innermost loop.
+These are implemented as builtin commands.
+.Pp
+The syntax of the case command is
+.Bd -literal -offset indent
+case word in
+[(]pattern) list ;;
+\&...
+esac
+.Ed
+.Pp
+The pattern can actually be one or more patterns (see
+.Sx Shell Patterns
+described later), separated by
+.Dq \*(Ba
+characters.
+The
+.Do
+(
+.Dc
+character before the pattern is optional.
+.Ss Grouping Commands Together
+Commands may be grouped by writing either
+.Pp
+.Dl (list)
+.Pp
+or
+.Pp
+.Dl { list; }
+.Pp
+The first of these executes the commands in a subshell.
+Builtin commands grouped into a (list) will not affect the current shell.
+The second form does not fork another shell so is slightly more efficient.
+Grouping commands together this way allows you to redirect
+their output as though they were one program:
+.Pp
+.Bd -literal -offset indent
+{ printf \*q hello \*q ; printf \*q world\\n" ; } \*[Gt] greeting
+.Ed
+.Pp
+Note that
+.Dq }
+must follow a control operator (here,
+.Dq \&; )
+so that it is recognized as a reserved word and not as another command argument.
+.Ss Functions
+The syntax of a function definition is
+.Pp
+.Dl name ( ) command
+.Pp
+A function definition is an executable statement; when executed it
+installs a function named name and returns an exit status of zero.
+The command is normally a list enclosed between
+.Dq {
+and
+.Dq } .
+.Pp
+Variables may be declared to be local to a function by using a local
+command.
+This should appear as the first statement of a function, and the syntax is
+.Pp
+.Dl local [ variable | - ] ...
+.Pp
+Local is implemented as a builtin command.
+.Pp
+When a variable is made local, it inherits the initial value and exported
+and readonly flags from the variable with the same name in the surrounding
+scope, if there is one.
+Otherwise, the variable is initially unset.
+The shell uses dynamic scoping, so that if you make the variable x local to
+function f, which then calls function g, references to the variable x made
+inside g will refer to the variable x declared inside f, not to the global
+variable named x.
+.Pp
+The only special parameter that can be made local is
+.Dq - .
+Making
+.Dq -
+local any shell options that are changed via the set command inside the
+function to be restored to their original values when the function
+returns.
+.Pp
+The syntax of the return command is
+.Pp
+.Dl return [ exitstatus ]
+.Pp
+It terminates the currently executing function.
+Return is implemented as a builtin command.
+.Ss Variables and Parameters
+The shell maintains a set of parameters.
+A parameter denoted by a name is called a variable.
+When starting up, the shell turns all the environment
+variables into shell variables.
+New variables can be set using the form
+.Pp
+.Dl name=value
+.Pp
+Variables set by the user must have a name consisting solely of
+alphabetics, numerics, and underscores - the first of which must not be
+numeric.
+A parameter can also be denoted by a number or a special
+character as explained below.
+.Ss Positional Parameters
+A positional parameter is a parameter denoted by a number (n \*[Gt] 0).
+The shell sets these initially to the values of its command line arguments
+that follow the name of the shell script.
+The
+.Ic set
+builtin can also be used to set or reset them.
+.Ss Special Parameters
+A special parameter is a parameter denoted by one of the following special
+characters.
+The value of the parameter is listed next to its character.
+.Bl -tag -width thinhyphena
+.It *
+Expands to the positional parameters, starting from one.
+When the
+expansion occurs within a double-quoted string it expands to a single
+field with the value of each parameter separated by the first character of
+the
+.Ev IFS
+variable, or by a
+.Aq space
+if
+.Ev IFS
+is unset.
+.It @
+Expands to the positional parameters, starting from one.
+When the expansion occurs within double-quotes, each positional
+parameter expands as a separate argument.
+If there are no positional parameters, the
+expansion of @ generates zero arguments, even when @ is
+double-quoted.
+What this basically means, for example, is
+if $1 is
+.Dq abc
+and $2 is
+.Dq def ghi ,
+then
+.Qq $@
+expands to
+the two arguments:
+.Pp
+.Sm off
+.Dl \*q abc \*q \  \*q def\ ghi \*q
+.Sm on
+.It #
+Expands to the number of positional parameters.
+.It ?
+Expands to the exit status of the most recent pipeline.
+.It - (Hyphen.)
+Expands to the current option flags (the single-letter
+option names concatenated into a string) as specified on
+invocation, by the set builtin command, or implicitly
+by the shell.
+.It $
+Expands to the process ID of the invoked shell.
+A subshell retains the same value of $ as its parent.
+.It !
+Expands to the process ID of the most recent background
+command executed from the current shell.
+For a pipeline, the process ID is that of the last command in the pipeline.
+.It 0 (Zero.)
+Expands to the name of the shell or shell script.
+.El
+.Ss Word Expansions
+This clause describes the various expansions that are performed on words.
+Not all expansions are performed on every word, as explained later.
+.Pp
+Tilde expansions, parameter expansions, command substitutions, arithmetic
+expansions, and quote removals that occur within a single word expand to a
+single field.
+It is only field splitting or pathname expansion that can
+create multiple fields from a single word.
+The single exception to this
+rule is the expansion of the special parameter @ within double-quotes, as
+was described above.
+.Pp
+The order of word expansion is:
+.Bl -enum
+.It
+Tilde Expansion, Parameter Expansion, Command Substitution,
+Arithmetic Expansion (these all occur at the same time).
+.It
+Field Splitting is performed on fields
+generated by step (1) unless the
+.Ev IFS
+variable is null.
+.It
+Pathname Expansion (unless set
+.Fl f
+is in effect).
+.It
+Quote Removal.
+.El
+.Pp
+The $ character is used to introduce parameter expansion, command
+substitution, or arithmetic evaluation.
+.Ss Tilde Expansion (substituting a user's home directory)
+A word beginning with an unquoted tilde character (~) is
+subjected to tilde expansion.
+All the characters up to
+a slash (/) or the end of the word are treated as a username
+and are replaced with the user's home directory.
+If the username is missing (as in
+.Pa ~/foobar ) ,
+the tilde is replaced with the value of the
+.Va HOME
+variable (the current user's home directory).
+.Ss Parameter Expansion
+The format for parameter expansion is as follows:
+.Pp
+.Dl ${expression}
+.Pp
+where expression consists of all characters until the matching
+.Dq } .
+Any
+.Dq }
+escaped by a backslash or within a quoted string, and characters in
+embedded arithmetic expansions, command substitutions, and variable
+expansions, are not examined in determining the matching
+.Dq } .
+.Pp
+The simplest form for parameter expansion is:
+.Pp
+.Dl ${parameter}
+.Pp
+The value, if any, of parameter is substituted.
+.Pp
+The parameter name or symbol can be enclosed in braces, which are
+optional except for positional parameters with more than one digit or
+when parameter is followed by a character that could be interpreted as
+part of the name.
+If a parameter expansion occurs inside double-quotes:
+.Bl -enum
+.It
+Pathname expansion is not performed on the results of the expansion.
+.It
+Field splitting is not performed on the results of the
+expansion, with the exception of @.
+.El
+.Pp
+In addition, a parameter expansion can be modified by using one of the
+following formats.
+.Bl -tag -width aaparameterwordaaaaa
+.It ${parameter:-word}
+Use Default Values.
+If parameter is unset or null, the expansion of word
+is substituted; otherwise, the value of parameter is substituted.
+.It ${parameter:=word}
+Assign Default Values.
+If parameter is unset or null, the expansion of
+word is assigned to parameter.
+In all cases, the final value of parameter is substituted.
+Only variables, not positional parameters or special
+parameters, can be assigned in this way.
+.It ${parameter:?[word]}
+Indicate Error if Null or Unset.
+If parameter is unset or null, the
+expansion of word (or a message indicating it is unset if word is omitted)
+is written to standard error and the shell exits with a nonzero exit status.
+Otherwise, the value of parameter is substituted.
+An interactive shell need not exit.
+.It ${parameter:+word}
+Use Alternative Value.
+If parameter is unset or null, null is
+substituted; otherwise, the expansion of word is substituted.
+.El
+.Pp
+In the parameter expansions shown previously, use of the colon in the
+format results in a test for a parameter that is unset or null; omission
+of the colon results in a test for a parameter that is only unset.
+.Bl -tag -width aaparameterwordaaaaa
+.It ${#parameter}
+String Length.
+The length in characters of the value of parameter.
+.El
+.Pp
+The following four varieties of parameter expansion provide for substring
+processing.
+In each case, pattern matching notation (see
+.Sx Shell Patterns ) ,
+rather than regular expression notation, is used to evaluate the patterns.
+If parameter is * or @, the result of the expansion is unspecified.
+Enclosing the full parameter expansion string in double-quotes does not
+cause the following four varieties of pattern characters to be quoted,
+whereas quoting characters within the braces has this effect.
+.Bl -tag -width aaparameterwordaaaaa
+.It ${parameter%word}
+Remove Smallest Suffix Pattern.
+The word is expanded to produce a pattern.
+The parameter expansion then results in parameter, with the
+smallest portion of the suffix matched by the pattern deleted.
+.It ${parameter%%word}
+Remove Largest Suffix Pattern.
+The word is expanded to produce a pattern.
+The parameter expansion then results in parameter, with the largest
+portion of the suffix matched by the pattern deleted.
+.It ${parameter#word}
+Remove Smallest Prefix Pattern.
+The word is expanded to produce a pattern.
+The parameter expansion then results in parameter, with the
+smallest portion of the prefix matched by the pattern deleted.
+.It ${parameter##word}
+Remove Largest Prefix Pattern.
+The word is expanded to produce a pattern.
+The parameter expansion then results in parameter, with the largest
+portion of the prefix matched by the pattern deleted.
+.El
+.Ss Command Substitution
+Command substitution allows the output of a command to be substituted in
+place of the command name itself.
+Command substitution occurs when the command is enclosed as follows:
+.Pp
+.Dl $(command)
+.Pp
+or
+.Po
+.Dq backquoted
+version
+.Pc :
+.Pp
+.Dl `command`
+.Pp
+The shell expands the command substitution by executing command in a
+subshell environment and replacing the command substitution with the
+standard output of the command, removing sequences of one or more
+.Ao newline Ac Ns s
+at the end of the substitution.
+(Embedded
+.Ao newline Ac Ns s
+before
+the end of the output are not removed; however, during field splitting,
+they may be translated into
+.Ao space Ac Ns s ,
+depending on the value of
+.Ev IFS
+and quoting that is in effect.)
+.Ss Arithmetic Expansion
+Arithmetic expansion provides a mechanism for evaluating an arithmetic
+expression and substituting its value.
+The format for arithmetic expansion is as follows:
+.Pp
+.Dl $((expression))
+.Pp
+The expression is treated as if it were in double-quotes, except
+that a double-quote inside the expression is not treated specially.
+The shell expands all tokens in the expression for parameter expansion,
+command substitution, and quote removal.
+.Pp
+Next, the shell treats this as an arithmetic expression and
+substitutes the value of the expression.
+.Ss White Space Splitting (Field Splitting)
+After parameter expansion, command substitution, and
+arithmetic expansion the shell scans the results of
+expansions and substitutions that did not occur in double-quotes for
+field splitting and multiple fields can result.
+.Pp
+The shell treats each character of the
+.Ev IFS
+as a delimiter and uses the delimiters to split the results of parameter
+expansion and command substitution into fields.
+.Ss Pathname Expansion (File Name Generation)
+Unless the
+.Fl f
+flag is set, file name generation is performed after word splitting is
+complete.
+Each word is viewed as a series of patterns, separated by slashes.
+The process of expansion replaces the word with the names of all
+existing files whose names can be formed by replacing each pattern with a
+string that matches the specified pattern.
+There are two restrictions on
+this: first, a pattern cannot match a string containing a slash, and
+second, a pattern cannot match a string starting with a period unless the
+first character of the pattern is a period.
+The next section describes the
+patterns used for both Pathname Expansion and the
+.Ic case
+command.
+.Ss Shell Patterns
+A pattern consists of normal characters, which match themselves,
+and meta-characters.
+The meta-characters are
+.Dq \&! ,
+.Dq * ,
+.Dq \&? ,
+and
+.Dq \&[ .
+These characters lose their special meanings if they are quoted.
+When command or variable substitution is performed
+and the dollar sign or back quotes are not double quoted,
+the value of the variable or the output of
+the command is scanned for these characters and they are turned into
+meta-characters.
+.Pp
+An asterisk
+.Pq Dq *
+matches any string of characters.
+A question mark matches any single character.
+A left bracket
+.Pq Dq \&[
+introduces a character class.
+The end of the character class is indicated by a
+.Pq Dq \&] ;
+if the
+.Dq \&]
+is missing then the
+.Dq \&[
+matches a
+.Dq \&[
+rather than introducing a character class.
+A character class matches any of the characters between the square brackets.
+A range of characters may be specified using a minus sign.
+The character class may be complemented
+by making an exclamation point the first character of the character class.
+.Pp
+To include a
+.Dq \&]
+in a character class, make it the first character listed (after the
+.Dq \&! ,
+if any).
+To include a minus sign, make it the first or last character listed.
+.Ss Builtins
+This section lists the builtin commands which are builtin because they
+need to perform some operation that can't be performed by a separate
+process.
+In addition to these, there are several other commands that may
+be builtin for efficiency (e.g.
+.Xr printf 1 ,
+.Xr echo 1 ,
+.Xr test 1 ,
+etc).
+.Bl -tag -width 5n
+.It :
+.It true
+A null command that returns a 0 (true) exit value.
+.It \&. file
+The commands in the specified file are read and executed by the shell.
+.It alias Op Ar name Ns Op Ar "=string ..."
+If
+.Ar name=string
+is specified, the shell defines the alias
+.Ar name
+with value
+.Ar string .
+If just
+.Ar name
+is specified, the value of the alias
+.Ar name
+is printed.
+With no arguments, the
+.Ic alias
+builtin prints the
+names and values of all defined aliases (see
+.Ic unalias ) .
+.It bg [ Ar job ] ...
+Continue the specified jobs (or the current job if no
+jobs are given) in the background.
+.It Xo command
+.Op Fl p
+.Op Fl v
+.Op Fl V
+.Ar command
+.Op Ar arg ...
+.Xc
+Execute the specified command but ignore shell functions when searching
+for it.
+(This is useful when you
+have a shell function with the same name as a builtin command.)
+.Bl -tag -width 5n
+.It Fl p
+search for command using a
+.Ev PATH
+that guarantees to find all the standard utilities.
+.It Fl V
+Do not execute the command but
+search for the command and print the resolution of the
+command search.
+This is the same as the type builtin.
+.It Fl v
+Do not execute the command but
+search for the command and print the absolute pathname
+of utilities, the name for builtins or the expansion of aliases.
+.El
+.It cd Ar -
+.It Xo cd Op Fl LP
+.Op Ar directory
+.Xc
+Switch to the specified directory (default
+.Ev HOME ) .
+If an entry for
+.Ev CDPATH
+appears in the environment of the
+.Ic cd
+command or the shell variable
+.Ev CDPATH
+is set and the directory name does not begin with a slash, then the
+directories listed in
+.Ev CDPATH
+will be searched for the specified directory.
+The format of
+.Ev CDPATH
+is the same as that of
+.Ev PATH .
+If a single dash is specified as the argument, it will be replaced by the
+value of
+.Ev OLDPWD .
+The
+.Ic cd
+command will print out the name of the
+directory that it actually switched to if this is different from the name
+that the user gave.
+These may be different either because the
+.Ev CDPATH
+mechanism was used or because the argument is a single dash.
+The
+.Fl P
+option causes the physical directory structure to be used, that is, all
+symbolic links are resolved to their respective values.  The
+.Fl L
+option turns off the effect of any preceding
+.Fl P
+options.
+.It Xo echo Op Fl n
+.Ar args... 
+.Xc
+Print the arguments on the standard output, separated by spaces.
+Unless the
+.Fl n
+option is present, a newline is output following the arguments.
+.Pp
+If any of the following sequences of characters is encountered during
+output, the sequence is not output.  Instead, the specified action is
+performed:
+.Bl -tag -width indent
+.It Li \eb
+A backspace character is output.
+.It Li \ec
+Subsequent output is suppressed.  This is normally used at the end of the
+last argument to suppress the trailing newline that
+.Ic echo
+would otherwise output.
+.It Li \ef
+Output a form feed.
+.It Li \en
+Output a newline character.
+.It Li \er
+Output a carriage return.
+.It Li \et
+Output a (horizontal) tab character.
+.It Li \ev
+Output a vertical tab.
+.It Li \e0 Ns Ar digits
+Output the character whose value is given by zero to three octal digits.
+If there are zero digits, a nul character is output.
+.It Li \e\e
+Output a backslash.
+.El
+.Pp
+All other backslash sequences elicit undefined behaviour.
+.It eval Ar string ...
+Concatenate all the arguments with spaces.
+Then re-parse and execute the command.
+.It exec Op Ar command arg ...
+Unless command is omitted, the shell process is replaced with the
+specified program (which must be a real program, not a shell builtin or
+function).
+Any redirections on the
+.Ic exec
+command are marked as permanent, so that they are not undone when the
+.Ic exec
+command finishes.
+.It exit Op Ar exitstatus
+Terminate the shell process.
+If
+.Ar exitstatus
+is given it is used as the exit status of the shell; otherwise the
+exit status of the preceding command is used.
+.It export Ar name ...
+.It export Fl p
+The specified names are exported so that they will appear in the
+environment of subsequent commands.
+The only way to un-export a variable is to unset it.
+The shell allows the value of a variable to be set at the
+same time it is exported by writing
+.Pp
+.Dl export name=value
+.Pp
+With no arguments the export command lists the names of all exported variables.
+With the
+.Fl p
+option specified the output will be formatted suitably for non-interactive use.
+.It Xo fc Op Fl e Ar editor
+.Op Ar first Op Ar last
+.Xc
+.It Xo fc Fl l
+.Op Fl nr
+.Op Ar first Op Ar last
+.Xc
+.It Xo fc Fl s Op Ar old=new
+.Op Ar first
+.Xc
+The
+.Ic fc
+builtin lists, or edits and re-executes, commands previously entered
+to an interactive shell.
+.Bl -tag -width 5n
+.It Fl e No editor
+Use the editor named by editor to edit the commands.
+The editor string is a command name, subject to search via the
+.Ev PATH
+variable.
+The value in the
+.Ev FCEDIT
+variable is used as a default when
+.Fl e
+is not specified.
+If
+.Ev FCEDIT
+is null or unset, the value of the
+.Ev EDITOR
+variable is used.
+If
+.Ev EDITOR
+is null or unset,
+.Xr ed 1
+is used as the editor.
+.It Fl l No (ell)
+List the commands rather than invoking an editor on them.
+The commands are written in the sequence indicated by
+the first and last operands, as affected by
+.Fl r ,
+with each command preceded by the command number.
+.It Fl n
+Suppress command numbers when listing with -l.
+.It Fl r
+Reverse the order of the commands listed (with
+.Fl l )
+or edited (with neither
+.Fl l
+nor
+.Fl s ) .
+.It Fl s
+Re-execute the command without invoking an editor.
+.It first
+.It last
+Select the commands to list or edit.
+The number of previous commands that
+can be accessed are determined by the value of the
+.Ev HISTSIZE
+variable.
+The value of first or last or both are one of the following:
+.Bl -tag -width 5n
+.It [+]number
+A positive number representing a command number; command numbers can be
+displayed with the
+.Fl l
+option.
+.It Fl number
+A negative decimal number representing the command that was executed
+number of commands previously.
+For example, \-1 is the immediately previous command.
+.El
+.It string
+A string indicating the most recently entered command that begins with
+that string.
+If the old=new operand is not also specified with
+.Fl s ,
+the string form of the first operand cannot contain an embedded equal sign.
+.El
+.Pp
+The following environment variables affect the execution of fc:
+.Bl -tag -width HISTSIZE
+.It Ev FCEDIT
+Name of the editor to use.
+.It Ev HISTSIZE
+The number of previous commands that are accessible.
+.El
+.It fg Op Ar job
+Move the specified job or the current job to the foreground.
+.It getopts Ar optstring var
+The
+.Tn POSIX
+.Ic getopts
+command, not to be confused with the
+.Em Bell Labs
+-derived
+.Xr getopt 1 .
+.Pp
+The first argument should be a series of letters, each of which may be
+optionally followed by a colon to indicate that the option requires an
+argument.
+The variable specified is set to the parsed option.
+.Pp
+The
+.Ic getopts
+command deprecates the older
+.Xr getopt 1
+utility due to its handling of arguments containing whitespace.
+.Pp
+The
+.Ic getopts
+builtin may be used to obtain options and their arguments
+from a list of parameters.
+When invoked,
+.Ic getopts
+places the value of the next option from the option string in the list in
+the shell variable specified by
+.Va var
+and its index in the shell variable
+.Ev OPTIND .
+When the shell is invoked,
+.Ev OPTIND
+is initialized to 1.
+For each option that requires an argument, the
+.Ic getopts
+builtin will place it in the shell variable
+.Ev OPTARG .
+If an option is not allowed for in the
+.Va optstring ,
+then
+.Ev OPTARG
+will be unset.
+.Pp
+.Va optstring
+is a string of recognized option letters (see
+.Xr getopt 3 ) .
+If a letter is followed by a colon, the option is expected to have an
+argument which may or may not be separated from it by white space.
+If an option character is not found where expected,
+.Ic getopts
+will set the variable
+.Va var
+to a
+.Dq \&? ;
+.Ic getopts
+will then unset
+.Ev OPTARG
+and write output to standard error.
+By specifying a colon as the first character of
+.Va optstring
+all errors will be ignored.
+.Pp
+After the last option
+.Ic getopts
+will return a non-zero value and set
+.Va var
+to
+.Dq \&? .
+.Pp
+The following code fragment shows how one might process the arguments
+for a command that can take the options
+.Op a
+and
+.Op b ,
+and the option
+.Op c ,
+which requires an argument.
+.Pp
+.Bd -literal -offset indent
+while getopts abc: f
+do
+	case $f in
+	a | b)	flag=$f;;
+	c)	carg=$OPTARG;;
+	\\?)	echo $USAGE; exit 1;;
+	esac
+done
+shift `expr $OPTIND - 1`
+.Ed
+.Pp
+This code will accept any of the following as equivalent:
+.Pp
+.Bd -literal -offset indent
+cmd \-acarg file file
+cmd \-a \-c arg file file
+cmd \-carg -a file file
+cmd \-a \-carg \-\- file file
+.Ed
+.It hash Fl rv Ar command ...
+The shell maintains a hash table which remembers the
+locations of commands.
+With no arguments whatsoever,
+the
+.Ic hash
+command prints out the contents of this table.
+Entries which have not been looked at since the last
+.Ic cd
+command are marked with an asterisk; it is possible for these entries
+to be invalid.
+.Pp
+With arguments, the
+.Ic hash
+command removes the specified commands from the hash table (unless
+they are functions) and then locates them.
+With the
+.Fl v
+option, hash prints the locations of the commands as it finds them.
+The
+.Fl r
+option causes the hash command to delete all the entries in the hash table
+except for functions.
+.It pwd Op Fl LP
+builtin command remembers what the current directory
+is rather than recomputing it each time.
+This makes it faster.
+However, if the current directory is renamed, the builtin version of
+.Ic pwd
+will continue to print the old name for the directory.
+The
+.Fl P
+option causes the physical value of the current working directory to be shown,
+that is, all symbolic links are resolved to their respective values.  The
+.Fl L
+option turns off the effect of any preceding
+.Fl P
+options.
+.It Xo read Op Fl p Ar prompt
+.Op Fl r
+.Ar variable
+.Op Ar ...
+.Xc
+The prompt is printed if the
+.Fl p
+option is specified and the standard input is a terminal.
+Then a line is read from the standard input.
+The trailing newline is deleted from the
+line and the line is split as described in the section on word splitting
+above, and the pieces are assigned to the variables in order.
+At least one variable must be specified.
+If there are more pieces than variables, the remaining pieces
+(along with the characters in
+.Ev IFS
+that separated them) are assigned to the last variable.
+If there are more variables than pieces,
+the remaining variables are assigned the null string.
+The
+.Ic read
+builtin will indicate success unless EOF is encountered on input, in
+which case failure is returned.
+.Pp
+By default, unless the
+.Fl r
+option is specified, the backslash
+.Dq \e
+acts as an escape character, causing the following character to be treated
+literally.
+If a backslash is followed by a newline, the backslash and the
+newline will be deleted.
+.It readonly Ar name ...
+.It readonly Fl p
+The specified names are marked as read only, so that they cannot be
+subsequently modified or unset.
+The shell allows the value of a variable
+to be set at the same time it is marked read only by writing
+.Pp
+.Dl readonly name=value
+.Pp
+With no arguments the readonly command lists the names of all read only
+variables.
+With the
+.Fl p
+option specified the output will be formatted suitably for non-interactive use.
+.Pp
+.It Xo printf Ar format
+.Op Ar arguments  ...
+.Xc
+.Ic printf
+formats and prints its arguments, after the first, under control
+of the
+.Ar format  .
+The
+.Ar format
+is a character string which contains three types of objects: plain characters,
+which are simply copied to standard output, character escape sequences which
+are converted and copied to the standard output, and format specifications,
+each of which causes printing of the next successive
+.Ar argument  .
+.Pp
+The
+.Ar arguments
+after the first are treated as strings if the corresponding format is
+either
+.Cm b ,
+.Cm c
+or
+.Cm s ;
+otherwise it is evaluated as a C constant, with the following extensions:
+.Pp
+.Bl -bullet -offset indent -compact
+.It
+A leading plus or minus sign is allowed.
+.It
+If the leading character is a single or double quote, the value is the
+.Tn ASCII
+code of the next character.
+.El
+.Pp
+The format string is reused as often as necessary to satisfy the
+.Ar arguments  .
+Any extra format specifications are evaluated with zero or the null
+string.
+.Pp
+Character escape sequences are in backslash notation as defined in
+.St -ansiC .
+The characters and their meanings are as follows:
+.Bl -tag -width Ds -offset indent
+.It Cm \ea
+Write a \*[Lt]bell\*[Gt] character.
+.It Cm \eb
+Write a \*[Lt]backspace\*[Gt] character.
+.It Cm \ef
+Write a \*[Lt]form-feed\*[Gt] character.
+.It Cm \en
+Write a \*[Lt]new-line\*[Gt] character.
+.It Cm \er
+Write a \*[Lt]carriage return\*[Gt] character.
+.It Cm \et
+Write a \*[Lt]tab\*[Gt] character.
+.It Cm \ev
+Write a \*[Lt]vertical tab\*[Gt] character.
+.It Cm \e\e
+Write a backslash character.
+.It Cm \e Ns Ar num
+Write an 8\-bit character whose
+.Tn ASCII
+value is the 1\-, 2\-, or 3\-digit
+octal number
+.Ar num .
+.El
+.Pp
+Each format specification is introduced by the percent character
+(``%'').
+The remainder of the format specification includes,
+in the following order:
+.Bl -tag -width Ds
+.It "Zero or more of the following flags:"
+.Bl -tag -width Ds
+.It Cm #
+A `#' character
+specifying that the value should be printed in an ``alternative form''.
+For
+.Cm b ,
+.Cm c ,
+.Cm d ,
+and
+.Cm s
+formats, this option has no effect.
+For the
+.Cm o
+format the precision of the number is increased to force the first
+character of the output string to a zero.
+For the
+.Cm x
+.Pq Cm X
+format, a non-zero result has the string
+.Li 0x
+.Pq Li 0X
+prepended to it.
+For
+.Cm e  ,
+.Cm E ,
+.Cm f  ,
+.Cm g ,
+and
+.Cm G
+formats, the result will always contain a decimal point, even if no
+digits follow the point (normally, a decimal point only appears in the
+results of those formats if a digit follows the decimal point).
+For
+.Cm g
+and
+.Cm G
+formats, trailing zeros are not removed from the result as they
+would otherwise be.
+.It Cm \&\-
+A minus sign `\-' which specifies
+.Em left adjustment
+of the output in the indicated field;
+.It Cm \&+
+A `+' character specifying that there should always be
+a sign placed before the number when using signed formats.
+.It Sq \&\ \&
+A space specifying that a blank should be left before a positive number
+for a signed format.
+A `+' overrides a space if both are used;
+.It Cm \&0
+A zero `0' character indicating that zero-padding should be used
+rather than blank-padding.
+A `\-' overrides a `0' if both are used;
+.El
+.It "Field Width:"
+An optional digit string specifying a
+.Em field width ;
+if the output string has fewer characters than the field width it will
+be blank-padded on the left (or right, if the left-adjustment indicator
+has been given) to make up the field width (note that a leading zero
+is a flag, but an embedded zero is part of a field width);
+.It Precision :
+An optional period,
+.Sq Cm \&.\& ,
+followed by an optional digit string giving a
+.Em precision
+which specifies the number of digits to appear after the decimal point,
+for
+.Cm e
+and
+.Cm f
+formats, or the maximum number of bytes to be printed
+from a string
+.Sm off
+.Pf ( Cm b
+.Sm on
+and
+.Cm s
+formats); if the digit string is missing, the precision is treated
+as zero;
+.It Format :
+A character which indicates the type of format to use (one of
+.Cm diouxXfwEgGbcs ) .
+.El
+.Pp
+A field width or precision may be
+.Sq Cm \&*
+instead of a digit string.
+In this case an
+.Ar argument
+supplies the field width or precision.
+.Pp
+The format characters and their meanings are:
+.Bl -tag -width Fl
+.It Cm diouXx
+The
+.Ar argument
+is printed as a signed decimal (d or i), unsigned octal, unsigned decimal,
+or unsigned hexadecimal (X or x), respectively.
+.It Cm f
+The
+.Ar argument
+is printed in the style
+.Sm off
+.Pf [\-]ddd Cm \&. No ddd
+.Sm on
+where the number of d's
+after the decimal point is equal to the precision specification for
+the argument.
+If the precision is missing, 6 digits are given; if the precision
+is explicitly 0, no digits and no decimal point are printed.
+.It Cm eE
+The
+.Ar argument
+is printed in the style
+.Sm off
+.Pf [\-]d Cm \&. No ddd Cm e No \*(Pmdd
+.Sm on
+where there
+is one digit before the decimal point and the number after is equal to
+the precision specification for the argument; when the precision is
+missing, 6 digits are produced.
+An upper-case E is used for an `E' format.
+.It Cm gG
+The
+.Ar argument
+is printed in style
+.Cm f
+or in style
+.Cm e
+.Pq Cm E
+whichever gives full precision in minimum space.
+.It Cm b
+Characters from the string
+.Ar argument
+are printed with backslash-escape sequences expanded.
+.br
+The following additional backslash-escape sequences are supported:
+.Bl -tag -width Ds
+.It Cm \ec
+Causes
+.Nm
+to ignore any remaining characters in the string operand containing it,
+any remaining string operands, and any additional characters in
+the format operand.
+.It Cm \e0 Ns Ar num
+Write an 8\-bit character whose
+.Tn ASCII
+value is the 1\-, 2\-, or 3\-digit
+octal number
+.Ar num .
+.El
+.It Cm c
+The first character of
+.Ar argument
+is printed.
+.It Cm s
+Characters from the string
+.Ar argument
+are printed until the end is reached or until the number of bytes
+indicated by the precision specification is reached; if the
+precision is omitted, all characters in the string are printed.
+.It Cm \&%
+Print a `%'; no argument is used.
+.El
+.Pp
+In no case does a non-existent or small field width cause truncation of
+a field; padding takes place only if the specified field width exceeds
+the actual width.
+.It Xo set
+.Oo {
+.Fl options | Cm +options | Cm -- }
+.Oc Ar arg ...
+.Xc
+The
+.Ic set
+command performs three different functions.
+.Pp
+With no arguments, it lists the values of all shell variables.
+.Pp
+If options are given, it sets the specified option
+flags, or clears them as described in the section called
+.Sx Argument List Processing .
+As a special case, if the option is -o or +o and no argument is
+supplied, the shell prints the settings of all its options.  If the
+option is -o, the settings are printed in a human-readable format; if
+the option is +o, the settings are printed in a format suitable for
+reinput to the shell to affect the same option settings.
+.Pp
+The third use of the set command is to set the values of the shell's
+positional parameters to the specified args.
+To change the positional
+parameters without changing any options, use
+.Dq --
+as the first argument to set.
+If no args are present, the set command
+will clear all the positional parameters (equivalent to executing
+.Dq shift $# . )
+.It shift Op Ar n
+Shift the positional parameters n times.
+A
+.Ic shift
+sets the value of
+.Va $1
+to the value of
+.Va $2 ,
+the value of
+.Va $2
+to the value of
+.Va $3 ,
+and so on, decreasing
+the value of
+.Va $#
+by one.
+If n is greater than the number of positional parameters,
+.Ic shift
+will issue an error message, and exit with return status 2.
+.It test Ar expression
+.It \&[ Ar expression Cm \&]
+The
+.Ic test
+utility evaluates the expression and, if it evaluates
+to true, returns a zero (true) exit status; otherwise
+it returns 1 (false).
+If there is no expression, test also
+returns 1 (false).
+.Pp
+All operators and flags are separate arguments to the
+.Ic test
+utility.
+.Pp
+The following primaries are used to construct expression:
+.Bl -tag -width Ar
+.It Fl b Ar file
+True if
+.Ar file
+exists and is a block special
+file.
+.It Fl c Ar file
+True if
+.Ar file
+exists and is a character
+special file.
+.It Fl d Ar file
+True if
+.Ar file
+exists and is a directory.
+.It Fl e Ar file
+True if
+.Ar file
+exists (regardless of type).
+.It Fl f Ar file
+True if
+.Ar file
+exists and is a regular file.
+.It Fl g Ar file
+True if
+.Ar file
+exists and its set group ID flag
+is set.
+.It Fl h Ar file
+True if
+.Ar file
+exists and is a symbolic link.
+.It Fl k Ar file
+True if
+.Ar file
+exists and its sticky bit is set.
+.It Fl n Ar string
+True if the length of
+.Ar string
+is nonzero.
+.It Fl p Ar file
+True if
+.Ar file
+is a named pipe
+.Po Tn FIFO Pc .
+.It Fl r Ar file
+True if
+.Ar file
+exists and is readable.
+.It Fl s Ar file
+True if
+.Ar file
+exists and has a size greater
+than zero.
+.It Fl t Ar file_descriptor
+True if the file whose file descriptor number
+is
+.Ar file_descriptor
+is open and is associated with a terminal.
+.It Fl u Ar file
+True if
+.Ar file
+exists and its set user ID flag
+is set.
+.It Fl w Ar file
+True if
+.Ar file
+exists and is writable.
+True
+indicates only that the write flag is on.
+The file is not writable on a read-only file
+system even if this test indicates true.
+.It Fl x Ar file
+True if
+.Ar file
+exists and is executable.
+True
+indicates only that the execute flag is on.
+If
+.Ar file
+is a directory, true indicates that
+.Ar file
+can be searched.
+.It Fl z Ar string
+True if the length of
+.Ar string
+is zero.
+.It Fl L Ar file
+True if
+.Ar file
+exists and is a symbolic link.
+This operator is retained for compatibility with previous versions of
+this program.
+Do not rely on its existence; use
+.Fl h
+instead.
+.It Fl O Ar file
+True if
+.Ar file
+exists and its owner matches the effective user id of this process.
+.It Fl G Ar file
+True if
+.Ar file
+exists and its group matches the effective group id of this process.
+.It Fl S Ar file
+True if
+.Ar file
+exists and is a socket.
+.It Ar file1 Fl nt Ar file2
+True if
+.Ar file1
+and
+.Ar file2
+exist and
+.Ar file1
+is newer than
+.Ar file2 .
+.It Ar file1 Fl ot Ar file2
+True if
+.Ar file1
+and
+.Ar file2
+exist and
+.Ar file1
+is older than
+.Ar file2 .
+.It Ar file1 Fl ef Ar file2
+True if
+.Ar file1
+and
+.Ar file2
+exist and refer to the same file.
+.It Ar string
+True if
+.Ar string
+is not the null
+string.
+.It Ar \&s\&1 Cm \&= Ar \&s\&2
+True if the strings
+.Ar \&s\&1
+and
+.Ar \&s\&2
+are identical.
+.It Ar \&s\&1 Cm \&!= Ar \&s\&2
+True if the strings
+.Ar \&s\&1
+and
+.Ar \&s\&2
+are not identical.
+.It Ar \&s\&1 Cm \&\*[Lt] Ar \&s\&2
+True if string
+.Ar \&s\&1
+comes before
+.Ar \&s\&2
+based on the ASCII value of their characters.
+.It Ar \&s\&1 Cm \&\*[Gt] Ar \&s\&2
+True if string
+.Ar \&s\&1
+comes after
+.Ar \&s\&2
+based on the ASCII value of their characters.
+.It Ar \&n\&1 Fl \&eq Ar \&n\&2
+True if the integers
+.Ar \&n\&1
+and
+.Ar \&n\&2
+are algebraically
+equal.
+.It Ar \&n\&1 Fl \&ne Ar \&n\&2
+True if the integers
+.Ar \&n\&1
+and
+.Ar \&n\&2
+are not
+algebraically equal.
+.It Ar \&n\&1 Fl \&gt Ar \&n\&2
+True if the integer
+.Ar \&n\&1
+is algebraically
+greater than the integer
+.Ar \&n\&2 .
+.It Ar \&n\&1 Fl \&ge Ar \&n\&2
+True if the integer
+.Ar \&n\&1
+is algebraically
+greater than or equal to the integer
+.Ar \&n\&2 .
+.It Ar \&n\&1 Fl \&lt Ar \&n\&2
+True if the integer
+.Ar \&n\&1
+is algebraically less
+than the integer
+.Ar \&n\&2 .
+.It Ar \&n\&1 Fl \&le Ar \&n\&2
+True if the integer
+.Ar \&n\&1
+is algebraically less
+than or equal to the integer
+.Ar \&n\&2 .
+.El
+.Pp
+These primaries can be combined with the following operators:
+.Bl -tag -width Ar
+.It Cm \&! Ar expression
+True if
+.Ar expression
+is false.
+.It Ar expression1 Fl a Ar expression2
+True if both
+.Ar expression1
+and
+.Ar expression2
+are true.
+.It Ar expression1 Fl o Ar expression2
+True if either
+.Ar expression1
+or
+.Ar expression2
+are true.
+.It Cm \&( Ns Ar expression Ns Cm \&)
+True if expression is true.
+.El
+.Pp
+The
+.Fl a
+operator has higher precedence than the
+.Fl o
+operator.
+.It times
+Print the accumulated user and system times for the shell and for processes
+run from the shell.  The return status is 0.
+.It Xo trap
+.Op Ar action Ar signal ...
+.Xc
+Cause the shell to parse and execute action when any of the specified
+signals are received.
+The signals are specified by signal number or as the name of the signal.
+If
+.Ar signal
+is
+.Li 0
+or
+.Li EXIT ,
+the action is executed when the shell exits.
+.Ar action
+may be empty
+.Li ( "''" ) ,
+which causes the specified signals to be ignored.
+With
+.Ar action
+omitted or set to `-' the specified signals are set to their default action.
+When the shell forks off a subshell, it resets trapped (but not ignored)
+signals to the default action.
+The
+.Ic trap
+command has no effect on signals that were
+ignored on entry to the shell.
+.Ic trap
+without any arguments cause it to write a list of signals and their
+associated action to the standard output in a format that is suitable
+as an input to the shell that achieves the same trapping results.
+.Pp
+Examples:
+.Pp
+.Dl trap
+.Pp
+List trapped signals and their corresponding action
+.Pp
+.Dl trap '' INT QUIT tstp 30
+.Pp
+Ignore signals INT QUIT TSTP USR1
+.Pp
+.Dl trap date INT
+.Pp
+Print date upon receiving signal INT
+.It type Op Ar name ...
+Interpret each name as a command and print the resolution of the command
+search.
+Possible resolutions are:
+shell keyword, alias, shell builtin,
+command, tracked alias and not found.
+For aliases the alias expansion is
+printed; for commands and tracked aliases the complete pathname of the
+command is printed.
+.It ulimit Xo
+.Op Fl H \*(Ba Fl S
+.Op Fl a \*(Ba Fl tfdscmlpnv Op Ar value
+.Xc
+Inquire about or set the hard or soft limits on processes or set new
+limits.
+The choice between hard limit (which no process is allowed to
+violate, and which may not be raised once it has been lowered) and soft
+limit (which causes processes to be signaled but not necessarily killed,
+and which may be raised) is made with these flags:
+.Bl -tag -width Fl
+.It Fl H
+set or inquire about hard limits
+.It Fl S
+set or inquire about soft limits.
+If neither
+.Fl H
+nor
+.Fl S
+is specified, the soft limit is displayed or both limits are set.
+If both are specified, the last one wins.
+.El
+.Pp
+The limit to be interrogated or set, then, is chosen by specifying
+any one of these flags:
+.Bl -tag -width Fl
+.It Fl a
+show all the current limits
+.It Fl t
+show or set the limit on CPU time (in seconds)
+.It Fl f
+show or set the limit on the largest file that can be created
+(in 512-byte blocks)
+.It Fl d
+show or set the limit on the data segment size of a process (in kilobytes)
+.It Fl s
+show or set the limit on the stack size of a process (in kilobytes)
+.It Fl c
+show or set the limit on the largest core dump size that can be produced
+(in 512-byte blocks)
+.It Fl m
+show or set the limit on the total physical memory that can be
+in use by a process (in kilobytes)
+.It Fl l
+show or set the limit on how much memory a process can lock with
+.Xr mlock 2
+(in kilobytes)
+.It Fl p
+show or set the limit on the number of processes this user can
+have at one time
+.It Fl n
+show or set the limit on the number files a process can have open at once
+.It Fl v
+show or set the limit on the total virtual memory that can be
+in use by a process (in kilobytes)
+.It Fl r
+show or set the limit on the real-time scheduling priority of a process
+.El
+.Pp
+If none of these is specified, it is the limit on file size that is shown
+or set.
+If value is specified, the limit is set to that number; otherwise
+the current limit is displayed.
+.Pp
+Limits of an arbitrary process can be displayed or set using the
+.Xr sysctl 8
+utility.
+.Pp
+.It umask Op Ar mask
+Set the value of umask (see
+.Xr umask 2 )
+to the specified octal value.
+If the argument is omitted, the umask value is printed.
+.It unalias Xo
+.Op Fl a
+.Op Ar name
+.Xc
+If
+.Ar name
+is specified, the shell removes that alias.
+If
+.Fl a
+is specified, all aliases are removed.
+.It unset Xo
+.Op Fl fv
+.Ar name ...
+.Xc
+The specified variables and functions are unset and unexported.
+If
+.Fl f
+or
+.Fl v
+is specified, the corresponding function or variable is unset, respectively.
+If a given name corresponds to both a variable and a function, and no
+options are given, only the variable is unset.
+.It wait Op Ar job
+Wait for the specified job to complete and return the exit status of the
+last process in the job.
+If the argument is omitted, wait for all jobs to
+complete and return an exit status of zero.
+.El
+.Ss Command Line Editing
+When
+.Nm
+is being used interactively from a terminal, the current command
+and the command history (see
+.Ic fc
+in
+.Sx Builtins )
+can be edited using vi-mode command-line editing.
+This mode uses commands, described below,
+similar to a subset of those described in the vi man page.
+The command
+.Ql set -o vi
+enables vi-mode editing and places sh into vi insert mode.
+With vi-mode
+enabled, sh can be switched between insert mode and command mode.
+It is similar to vi: typing
+.Aq ESC
+enters vi command mode.
+Hitting
+.Aq return
+while in command mode will pass the line to the shell.
+.Sh EXIT STATUS
+Errors that are detected by the shell, such as a syntax error, will cause the
+shell to exit with a non-zero exit status.
+If the shell is not an
+interactive shell, the execution of the shell file will be aborted.
+Otherwise
+the shell will return the exit status of the last command executed, or
+if the exit builtin is used with a numeric argument, it will return the
+argument.
+.Sh ENVIRONMENT
+.Bl -tag -width MAILCHECK
+.It Ev HOME
+Set automatically by
+.Xr login 1
+from the user's login directory in the password file
+.Pq Xr passwd 4 .
+This environment variable also functions as the default argument for the
+cd builtin.
+.It Ev PATH
+The default search path for executables.
+See the above section
+.Sx Path Search .
+.It Ev CDPATH
+The search path used with the cd builtin.
+.It Ev MAIL
+The name of a mail file, that will be checked for the arrival of new mail.
+Overridden by
+.Ev MAILPATH .
+.It Ev MAILCHECK
+The frequency in seconds that the shell checks for the arrival of mail
+in the files specified by the
+.Ev MAILPATH
+or the
+.Ev MAIL
+file.
+If set to 0, the check will occur at each prompt.
+.It Ev MAILPATH
+A colon
+.Dq \&:
+separated list of file names, for the shell to check for incoming mail.
+This environment setting overrides the
+.Ev MAIL
+setting.
+There is a maximum of 10 mailboxes that can be monitored at once.
+.It Ev PS1
+The primary prompt string, which defaults to
+.Dq $\  ,
+unless you are the superuser, in which case it defaults to
+.Dq #\  .
+.It Ev PS2
+The secondary prompt string, which defaults to
+.Dq \*[Gt]\  .
+.It Ev PS4
+Output before each line when execution trace (set -x) is enabled,
+defaults to
+.Dq +\  .
+.It Ev IFS
+Input Field Separators.
+This is normally set to
+.Aq space ,
+.Aq tab ,
+and
+.Aq newline .
+See the
+.Sx White Space Splitting
+section for more details.
+.It Ev TERM
+The default terminal setting for the shell.
+This is inherited by
+children of the shell, and is used in the history editing modes.
+.It Ev HISTSIZE
+The number of lines in the history buffer for the shell.
+.It Ev PWD
+The logical value of the current working directory.  This is set by the
+.Ic cd
+command.
+.It Ev OLDPWD
+The previous logical value of the current working directory.  This is set by
+the
+.Ic cd
+command.
+.It Ev PPID
+The process ID of the parent process of the shell.
+.El
+.Sh FILES
+.Bl -item -width HOMEprofilexxxx
+.It
+.Pa $HOME/.profile
+.It
+.Pa /etc/profile
+.El
+.Sh SEE ALSO
+.Xr csh 1 ,
+.Xr echo 1 ,
+.Xr getopt 1 ,
+.Xr ksh 1 ,
+.Xr login 1 ,
+.Xr printf 1 ,
+.Xr test 1 ,
+.Xr getopt 3 ,
+.Xr passwd 5 ,
+.\" .Xr profile 4 ,
+.Xr environ 7 ,
+.Xr sysctl 8
+.Sh HISTORY
+.Nm
+is a POSIX-compliant implementation of /bin/sh that aims to be as small as
+possible.
+.Nm
+is a direct descendant of the NetBSD version of ash (the Almquist SHell),
+ported to Linux in early 1997.
+It was renamed to
+.Nm
+in 2002.
+.Sh BUGS
+Setuid shell scripts should be avoided at all costs, as they are a
+significant security risk.
+.Pp
+PS1, PS2, and PS4 should be subject to parameter expansion before
+being displayed.
diff --git a/src/error.c b/src/error.c
new file mode 100644
index 00000000..728ff885
--- /dev/null
+++ b/src/error.c
@@ -0,0 +1,238 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Errors and exceptions.
+ */
+
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "jobs.h"
+#include "shell.h"
+#include "main.h"
+#include "options.h"
+#include "output.h"
+#include "error.h"
+#include "show.h"
+#include "eval.h"
+#include "parser.h"
+#include "system.h"
+
+
+/*
+ * Code to handle exceptions in C.
+ */
+
+struct jmploc *handler;
+int exception;
+int suppressint;
+volatile sig_atomic_t intpending;
+int errlinno;
+
+
+static void exverror(int, const char *, va_list)
+    __attribute__((__noreturn__));
+
+/*
+ * Called to raise an exception.  Since C doesn't include exceptions, we
+ * just do a longjmp to the exception handler.  The type of exception is
+ * stored in the global variable "exception".
+ */
+
+void
+exraise(int e)
+{
+#ifdef DEBUG
+	if (handler == NULL)
+		abort();
+#endif
+
+	if (vforked)
+		_exit(exitstatus);
+
+	INTOFF;
+
+	exception = e;
+	longjmp(handler->loc, 1);
+}
+
+
+/*
+ * Called from trap.c when a SIGINT is received.  (If the user specifies
+ * that SIGINT is to be trapped or ignored using the trap builtin, then
+ * this routine is not called.)  Suppressint is nonzero when interrupts
+ * are held using the INTOFF macro.  (The test for iflag is just
+ * defensive programming.)
+ */
+
+void
+onint(void) {
+
+	intpending = 0;
+	sigclearmask();
+	if (!(rootshell && iflag)) {
+		signal(SIGINT, SIG_DFL);
+		raise(SIGINT);
+	}
+	exitstatus = SIGINT + 128;
+	exraise(EXINT);
+	/* NOTREACHED */
+}
+
+static void
+exvwarning2(const char *msg, va_list ap)
+{
+	struct output *errs;
+	const char *name;
+	const char *fmt;
+
+	errs = out2;
+	name = arg0 ? arg0 : "sh";
+	if (!commandname)
+		fmt = "%s: %d: ";
+	else
+		fmt = "%s: %d: %s: ";
+	outfmt(errs, fmt, name, errlinno, commandname);
+	doformat(errs, msg, ap);
+#if FLUSHERR
+	outc('\n', errs);
+#else
+	outcslow('\n', errs);
+#endif
+}
+
+#define exvwarning(a, b, c) exvwarning2(b, c)
+
+/*
+ * Exverror is called to raise the error exception.  If the second argument
+ * is not NULL then error prints an error message using printf style
+ * formatting.  It then raises the error exception.
+ */
+static void
+exverror(int cond, const char *msg, va_list ap)
+{
+#ifdef DEBUG
+	if (msg) {
+		va_list aq;
+		TRACE(("exverror(%d, \"", cond));
+		va_copy(aq, ap);
+		TRACEV((msg, aq));
+		va_end(aq);
+		TRACE(("\") pid=%d\n", getpid()));
+	} else
+		TRACE(("exverror(%d, NULL) pid=%d\n", cond, getpid()));
+	if (msg)
+#endif
+		exvwarning(-1, msg, ap);
+
+	flushall();
+	exraise(cond);
+	/* NOTREACHED */
+}
+
+
+void
+sh_error(const char *msg, ...)
+{
+	va_list ap;
+
+	exitstatus = 2;
+
+	va_start(ap, msg);
+	exverror(EXERROR, msg, ap);
+	/* NOTREACHED */
+	va_end(ap);
+}
+
+
+void
+exerror(int cond, const char *msg, ...)
+{
+	va_list ap;
+
+	va_start(ap, msg);
+	exverror(cond, msg, ap);
+	/* NOTREACHED */
+	va_end(ap);
+}
+
+/*
+ * error/warning routines for external builtins
+ */
+
+void
+sh_warnx(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	exvwarning(-1, fmt, ap);
+	va_end(ap);
+}
+
+
+/*
+ * Return a string describing an error.  The returned string may be a
+ * pointer to a static buffer that will be overwritten on the next call.
+ * Action describes the operation that got the error.
+ */
+
+const char *
+errmsg(int e, int action)
+{
+	if (e != ENOENT && e != ENOTDIR)
+		return strerror(e);
+
+	if (action & E_OPEN)
+		return "No such file";
+	else if (action & E_CREAT)
+		return "Directory nonexistent";
+	else
+		return "not found";
+}
+
+
+#ifdef REALLY_SMALL
+void
+__inton() {
+	if (--suppressint == 0 && intpending) {
+		onint();
+	}
+}
+#endif
diff --git a/src/error.h b/src/error.h
new file mode 100644
index 00000000..94e30a27
--- /dev/null
+++ b/src/error.h
@@ -0,0 +1,129 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)error.h	8.2 (Berkeley) 5/4/95
+ */
+
+#include <setjmp.h>
+#include <signal.h>
+
+/*
+ * Types of operations (passed to the errmsg routine).
+ */
+
+#define E_OPEN 01	/* opening a file */
+#define E_CREAT 02	/* creating a file */
+#define E_EXEC 04	/* executing a program */
+
+
+/*
+ * We enclose jmp_buf in a structure so that we can declare pointers to
+ * jump locations.  The global variable handler contains the location to
+ * jump to when an exception occurs, and the global variable exception
+ * contains a code identifying the exeception.  To implement nested
+ * exception handlers, the user should save the value of handler on entry
+ * to an inner scope, set handler to point to a jmploc structure for the
+ * inner scope, and restore handler on exit from the scope.
+ */
+
+struct jmploc {
+	jmp_buf loc;
+};
+
+extern struct jmploc *handler;
+extern int exception;
+
+/* exceptions */
+#define EXINT 0		/* SIGINT received */
+#define EXERROR 1	/* a generic error */
+#define EXEND 3		/* exit the shell */
+#define EXEXIT 4	/* exit the shell via exitcmd */
+
+
+/*
+ * These macros allow the user to suspend the handling of interrupt signals
+ * over a period of time.  This is similar to SIGHOLD to or sigblock, but
+ * much more efficient and portable.  (But hacking the kernel is so much
+ * more fun than worrying about efficiency and portability. :-))
+ */
+
+extern int suppressint;
+extern volatile sig_atomic_t intpending;
+
+#define barrier() ({ __asm__ __volatile__ ("": : :"memory"); })
+#define INTOFF \
+	({ \
+		suppressint++; \
+		barrier(); \
+		0; \
+	})
+#ifdef REALLY_SMALL
+void __inton(void);
+#define INTON __inton()
+#else
+#define INTON \
+	({ \
+		barrier(); \
+		if (--suppressint == 0 && intpending) onint(); \
+		0; \
+	})
+#endif
+#define FORCEINTON \
+	({ \
+		barrier(); \
+		suppressint = 0; \
+		if (intpending) onint(); \
+		0; \
+	})
+#define SAVEINT(v) ((v) = suppressint)
+#define RESTOREINT(v) \
+	({ \
+		barrier(); \
+		if ((suppressint = (v)) == 0 && intpending) onint(); \
+		0; \
+	})
+#define CLEAR_PENDING_INT intpending = 0
+#define int_pending() intpending
+
+void exraise(int) __attribute__((__noreturn__));
+#ifdef USE_NORETURN
+void onint(void) __attribute__((__noreturn__));
+#else
+void onint(void);
+#endif
+extern int errlinno;
+void sh_error(const char *, ...) __attribute__((__noreturn__));
+void exerror(int, const char *, ...) __attribute__((__noreturn__));
+const char *errmsg(int, int);
+
+void sh_warnx(const char *, ...);
diff --git a/src/eval.c b/src/eval.c
new file mode 100644
index 00000000..1b5d61dc
--- /dev/null
+++ b/src/eval.c
@@ -0,0 +1,1147 @@
+/*-
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+/*
+ * Evaluate a command.
+ */
+
+#include "init.h"
+#include "main.h"
+#include "shell.h"
+#include "nodes.h"
+#include "syntax.h"
+#include "expand.h"
+#include "parser.h"
+#include "jobs.h"
+#include "eval.h"
+#include "builtins.h"
+#include "options.h"
+#include "exec.h"
+#include "redir.h"
+#include "input.h"
+#include "output.h"
+#include "trap.h"
+#include "var.h"
+#include "memalloc.h"
+#include "error.h"
+#include "show.h"
+#include "mystring.h"
+#ifndef SMALL
+#include "myhistedit.h"
+#endif
+
+
+int evalskip;			/* set if we are skipping commands */
+STATIC int skipcount;		/* number of levels to skip */
+MKINIT int loopnest;		/* current loop nesting level */
+static int funcline;		/* starting line number of current function, or 0 if not in a function */
+
+
+char *commandname;
+int exitstatus;			/* exit status of last command */
+int back_exitstatus;		/* exit status of backquoted command */
+int savestatus = -1;		/* exit status of last command outside traps */
+
+
+#if !defined(__alpha__) || (defined(__GNUC__) && __GNUC__ >= 3)
+STATIC
+#endif
+void evaltreenr(union node *, int) __attribute__ ((__noreturn__));
+STATIC int evalloop(union node *, int);
+STATIC int evalfor(union node *, int);
+STATIC int evalcase(union node *, int);
+STATIC int evalsubshell(union node *, int);
+STATIC void expredir(union node *);
+STATIC int evalpipe(union node *, int);
+#ifdef notyet
+STATIC int evalcommand(union node *, int, struct backcmd *);
+#else
+STATIC int evalcommand(union node *, int);
+#endif
+STATIC int evalbltin(const struct builtincmd *, int, char **, int);
+STATIC int evalfun(struct funcnode *, int, char **, int);
+STATIC void prehash(union node *);
+STATIC int eprintlist(struct output *, struct strlist *, int);
+STATIC int bltincmd(int, char **);
+
+
+STATIC const struct builtincmd bltin = {
+	.name = nullstr,
+	.builtin = bltincmd,
+	.flags = BUILTIN_REGULAR,
+};
+
+
+/*
+ * Called to reset things after an exception.
+ */
+
+#ifdef mkinit
+INCLUDE "eval.h"
+
+EXITRESET {
+	if (savestatus >= 0) {
+		if (exception == EXEXIT || evalskip == SKIPFUNCDEF)
+			exitstatus = savestatus;
+		savestatus = -1;
+	}
+	evalskip = 0;
+	loopnest = 0;
+}
+#endif
+
+
+
+/*
+ * The eval commmand.
+ */
+
+static int evalcmd(int argc, char **argv, int flags)
+{
+        char *p;
+        char *concat;
+        char **ap;
+
+        if (argc > 1) {
+                p = argv[1];
+                if (argc > 2) {
+                        STARTSTACKSTR(concat);
+                        ap = argv + 2;
+                        for (;;) {
+                        	concat = stputs(p, concat);
+                                if ((p = *ap++) == NULL)
+                                        break;
+                                STPUTC(' ', concat);
+                        }
+                        STPUTC('\0', concat);
+                        p = grabstackstr(concat);
+                }
+                return evalstring(p, flags & EV_TESTED);
+        }
+        return 0;
+}
+
+
+/*
+ * Execute a command or commands contained in a string.
+ */
+
+int
+evalstring(char *s, int flags)
+{
+	union node *n;
+	struct stackmark smark;
+	int status;
+
+	s = sstrdup(s);
+	setinputstring(s);
+	setstackmark(&smark);
+
+	status = 0;
+	for (; (n = parsecmd(0)) != NEOF; popstackmark(&smark)) {
+		int i;
+
+		i = evaltree(n, flags & ~(parser_eof() ? 0 : EV_EXIT));
+		if (n)
+			status = i;
+
+		if (evalskip)
+			break;
+	}
+	popstackmark(&smark);
+	popfile();
+	stunalloc(s);
+
+	return status;
+}
+
+
+
+/*
+ * Evaluate a parse tree.  The value is left in the global variable
+ * exitstatus.
+ */
+
+int
+evaltree(union node *n, int flags)
+{
+	int checkexit = 0;
+	int (*evalfn)(union node *, int);
+	struct stackmark smark;
+	unsigned isor;
+	int status = 0;
+
+	setstackmark(&smark);
+
+	if (n == NULL) {
+		TRACE(("evaltree(NULL) called\n"));
+		goto out;
+	}
+
+	dotrap();
+
+#ifndef SMALL
+	displayhist = 1;	/* show history substitutions done with fc */
+#endif
+	TRACE(("pid %d, evaltree(%p: %d, %d) called\n",
+	    getpid(), n, n->type, flags));
+	switch (n->type) {
+	default:
+#ifdef DEBUG
+		out1fmt("Node type = %d\n", n->type);
+#ifndef USE_GLIBC_STDIO
+		flushout(out1);
+#endif
+		break;
+#endif
+	case NNOT:
+		status = !evaltree(n->nnot.com, EV_TESTED);
+		goto setstatus;
+	case NREDIR:
+		errlinno = lineno = n->nredir.linno;
+		if (funcline)
+			lineno -= funcline - 1;
+		expredir(n->nredir.redirect);
+		pushredir(n->nredir.redirect);
+		status = redirectsafe(n->nredir.redirect, REDIR_PUSH) ?:
+			 evaltree(n->nredir.n, flags & EV_TESTED);
+		if (n->nredir.redirect)
+			popredir(0);
+		goto setstatus;
+	case NCMD:
+#ifdef notyet
+		if (eflag && !(flags & EV_TESTED))
+			checkexit = ~0;
+		status = evalcommand(n, flags, (struct backcmd *)NULL);
+		goto setstatus;
+#else
+		evalfn = evalcommand;
+checkexit:
+		if (eflag && !(flags & EV_TESTED))
+			checkexit = ~0;
+		goto calleval;
+#endif
+	case NFOR:
+		evalfn = evalfor;
+		goto calleval;
+	case NWHILE:
+	case NUNTIL:
+		evalfn = evalloop;
+		goto calleval;
+	case NSUBSHELL:
+	case NBACKGND:
+		evalfn = evalsubshell;
+		goto checkexit;
+	case NPIPE:
+		evalfn = evalpipe;
+		goto checkexit;
+	case NCASE:
+		evalfn = evalcase;
+		goto calleval;
+	case NAND:
+	case NOR:
+	case NSEMI:
+#if NAND + 1 != NOR
+#error NAND + 1 != NOR
+#endif
+#if NOR + 1 != NSEMI
+#error NOR + 1 != NSEMI
+#endif
+		isor = n->type - NAND;
+		status = evaltree(n->nbinary.ch1,
+				  (flags | ((isor >> 1) - 1)) & EV_TESTED);
+		if ((!status) == isor || evalskip)
+			break;
+		n = n->nbinary.ch2;
+evaln:
+		evalfn = evaltree;
+calleval:
+		status = evalfn(n, flags);
+		goto setstatus;
+	case NIF:
+		status = evaltree(n->nif.test, EV_TESTED);
+		if (evalskip)
+			break;
+		if (!status) {
+			n = n->nif.ifpart;
+			goto evaln;
+		} else if (n->nif.elsepart) {
+			n = n->nif.elsepart;
+			goto evaln;
+		}
+		status = 0;
+		goto setstatus;
+	case NDEFUN:
+		defun(n);
+setstatus:
+		exitstatus = status;
+		break;
+	}
+out:
+	dotrap();
+
+	if (checkexit & status)
+		goto exexit;
+
+	if (flags & EV_EXIT) {
+exexit:
+		exraise(EXEND);
+	}
+
+	popstackmark(&smark);
+
+	return exitstatus;
+}
+
+
+#if !defined(__alpha__) || (defined(__GNUC__) && __GNUC__ >= 3)
+STATIC
+#endif
+void evaltreenr(union node *n, int flags)
+#ifdef HAVE_ATTRIBUTE_ALIAS
+	__attribute__ ((alias("evaltree")));
+#else
+{
+	evaltree(n, flags);
+	abort();
+}
+#endif
+
+
+static int skiploop(void)
+{
+	int skip = evalskip;
+
+	switch (skip) {
+	case 0:
+		break;
+
+	case SKIPBREAK:
+	case SKIPCONT:
+		if (likely(--skipcount <= 0)) {
+			evalskip = 0;
+			break;
+		}
+
+		skip = SKIPBREAK;
+		break;
+	}
+
+	return skip;
+}
+
+
+STATIC int
+evalloop(union node *n, int flags)
+{
+	int skip;
+	int status;
+
+	loopnest++;
+	status = 0;
+	flags &= EV_TESTED;
+	do {
+		int i;
+
+		i = evaltree(n->nbinary.ch1, EV_TESTED);
+		skip = skiploop();
+		if (skip == SKIPFUNC)
+			status = i;
+		if (skip)
+			continue;
+		if (n->type != NWHILE)
+			i = !i;
+		if (i != 0)
+			break;
+		status = evaltree(n->nbinary.ch2, flags);
+		skip = skiploop();
+	} while (!(skip & ~SKIPCONT));
+	loopnest--;
+
+	return status;
+}
+
+
+
+STATIC int
+evalfor(union node *n, int flags)
+{
+	struct arglist arglist;
+	union node *argp;
+	struct strlist *sp;
+	int status;
+
+	errlinno = lineno = n->nfor.linno;
+	if (funcline)
+		lineno -= funcline - 1;
+
+	arglist.lastp = &arglist.list;
+	for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
+		expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
+	}
+	*arglist.lastp = NULL;
+
+	status = 0;
+	loopnest++;
+	flags &= EV_TESTED;
+	for (sp = arglist.list ; sp ; sp = sp->next) {
+		setvar(n->nfor.var, sp->text, 0);
+		status = evaltree(n->nfor.body, flags);
+		if (skiploop() & ~SKIPCONT)
+			break;
+	}
+	loopnest--;
+
+	return status;
+}
+
+
+
+STATIC int
+evalcase(union node *n, int flags)
+{
+	union node *cp;
+	union node *patp;
+	struct arglist arglist;
+	int status = 0;
+
+	errlinno = lineno = n->ncase.linno;
+	if (funcline)
+		lineno -= funcline - 1;
+
+	arglist.lastp = &arglist.list;
+	expandarg(n->ncase.expr, &arglist, EXP_TILDE);
+	for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) {
+		for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) {
+			if (casematch(patp, arglist.list->text)) {
+				/* Ensure body is non-empty as otherwise
+				 * EV_EXIT may prevent us from setting the
+				 * exit status.
+				 */
+				if (evalskip == 0 && cp->nclist.body) {
+					status = evaltree(cp->nclist.body,
+							  flags);
+				}
+				goto out;
+			}
+		}
+	}
+out:
+	return status;
+}
+
+
+
+/*
+ * Kick off a subshell to evaluate a tree.
+ */
+
+STATIC int
+evalsubshell(union node *n, int flags)
+{
+	struct job *jp;
+	int backgnd = (n->type == NBACKGND);
+	int status;
+
+	errlinno = lineno = n->nredir.linno;
+	if (funcline)
+		lineno -= funcline - 1;
+
+	expredir(n->nredir.redirect);
+	INTOFF;
+	if (!backgnd && flags & EV_EXIT && !have_traps()) {
+		forkreset();
+		goto nofork;
+	}
+	jp = makejob(n, 1);
+	if (forkshell(jp, n, backgnd) == 0) {
+		flags |= EV_EXIT;
+		if (backgnd)
+			flags &=~ EV_TESTED;
+nofork:
+		INTON;
+		redirect(n->nredir.redirect, 0);
+		evaltreenr(n->nredir.n, flags);
+		/* never returns */
+	}
+	status = 0;
+	if (! backgnd)
+		status = waitforjob(jp);
+	INTON;
+	return status;
+}
+
+
+
+/*
+ * Compute the names of the files in a redirection list.
+ */
+
+STATIC void
+expredir(union node *n)
+{
+	union node *redir;
+
+	for (redir = n ; redir ; redir = redir->nfile.next) {
+		struct arglist fn;
+		fn.lastp = &fn.list;
+		switch (redir->type) {
+		case NFROMTO:
+		case NFROM:
+		case NTO:
+		case NCLOBBER:
+		case NAPPEND:
+			expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
+			redir->nfile.expfname = fn.list->text;
+			break;
+		case NFROMFD:
+		case NTOFD:
+			if (redir->ndup.vname) {
+				expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR);
+				fixredir(redir, fn.list->text, 1);
+			}
+			break;
+		}
+	}
+}
+
+
+
+/*
+ * Evaluate a pipeline.  All the processes in the pipeline are children
+ * of the process creating the pipeline.  (This differs from some versions
+ * of the shell, which make the last process in a pipeline the parent
+ * of all the rest.)
+ */
+
+STATIC int
+evalpipe(union node *n, int flags)
+{
+	struct job *jp;
+	struct nodelist *lp;
+	int pipelen;
+	int prevfd;
+	int pip[2];
+	int status = 0;
+
+	TRACE(("evalpipe(0x%lx) called\n", (long)n));
+	pipelen = 0;
+	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
+		pipelen++;
+	flags |= EV_EXIT;
+	INTOFF;
+	jp = makejob(n, pipelen);
+	prevfd = -1;
+	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
+		prehash(lp->n);
+		pip[1] = -1;
+		if (lp->next) {
+			if (pipe(pip) < 0) {
+				close(prevfd);
+				sh_error("Pipe call failed");
+			}
+		}
+		if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
+			INTON;
+			if (pip[1] >= 0) {
+				close(pip[0]);
+			}
+			if (prevfd > 0) {
+				dup2(prevfd, 0);
+				close(prevfd);
+			}
+			if (pip[1] > 1) {
+				dup2(pip[1], 1);
+				close(pip[1]);
+			}
+			evaltreenr(lp->n, flags);
+			/* never returns */
+		}
+		if (prevfd >= 0)
+			close(prevfd);
+		prevfd = pip[0];
+		close(pip[1]);
+	}
+	if (n->npipe.backgnd == 0) {
+		status = waitforjob(jp);
+		TRACE(("evalpipe:  job done exit status %d\n", status));
+	}
+	INTON;
+
+	return status;
+}
+
+
+
+/*
+ * Execute a command inside back quotes.  If it's a builtin command, we
+ * want to save its output in a block obtained from malloc.  Otherwise
+ * we fork off a subprocess and get the output of the command via a pipe.
+ * Should be called with interrupts off.
+ */
+
+void
+evalbackcmd(union node *n, struct backcmd *result)
+{
+	int pip[2];
+	struct job *jp;
+
+	result->fd = -1;
+	result->buf = NULL;
+	result->nleft = 0;
+	result->jp = NULL;
+	if (n == NULL) {
+		goto out;
+	}
+
+	if (pipe(pip) < 0)
+		sh_error("Pipe call failed");
+	jp = makejob(n, 1);
+	if (forkshell(jp, n, FORK_NOJOB) == 0) {
+		FORCEINTON;
+		close(pip[0]);
+		if (pip[1] != 1) {
+			dup2(pip[1], 1);
+			close(pip[1]);
+		}
+		ifsfree();
+		evaltreenr(n, EV_EXIT);
+		/* NOTREACHED */
+	}
+	close(pip[1]);
+	result->fd = pip[0];
+	result->jp = jp;
+
+out:
+	TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
+		result->fd, result->buf, result->nleft, result->jp));
+}
+
+static struct strlist *fill_arglist(struct arglist *arglist,
+				    union node **argpp)
+{
+	struct strlist **lastp = arglist->lastp;
+	union node *argp;
+
+	while ((argp = *argpp)) {
+		expandarg(argp, arglist, EXP_FULL | EXP_TILDE);
+		*argpp = argp->narg.next;
+		if (*lastp)
+			break;
+	}
+
+	return *lastp;
+}
+
+static int parse_command_args(struct arglist *arglist, union node **argpp,
+			      const char **path)
+{
+	struct strlist *sp = arglist->list;
+	char *cp, c;
+
+	for (;;) {
+		sp = unlikely(sp->next) ? sp->next :
+					  fill_arglist(arglist, argpp);
+		if (!sp)
+			return 0;
+		cp = sp->text;
+		if (*cp++ != '-')
+			break;
+		if (!(c = *cp++))
+			break;
+		if (c == '-' && !*cp) {
+			if (likely(!sp->next) && !fill_arglist(arglist, argpp))
+				return 0;
+			sp = sp->next;
+			break;
+		}
+		do {
+			switch (c) {
+			case 'p':
+				*path = defpath;
+				break;
+			default:
+				/* run 'typecmd' for other options */
+				return 0;
+			}
+		} while ((c = *cp++));
+	}
+
+	arglist->list = sp;
+	return DO_NOFUNC;
+}
+
+/*
+ * Execute a simple command.
+ */
+
+STATIC int
+#ifdef notyet
+evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
+#else
+evalcommand(union node *cmd, int flags)
+#endif
+{
+	struct localvar_list *localvar_stop;
+	struct parsefile *file_stop;
+	struct redirtab *redir_stop;
+	union node *argp;
+	struct arglist arglist;
+	struct arglist varlist;
+	char **argv;
+	int argc;
+	struct strlist *osp;
+	struct strlist *sp;
+#ifdef notyet
+	int pip[2];
+#endif
+	struct cmdentry cmdentry;
+	struct job *jp;
+	char *lastarg;
+	const char *path;
+	int spclbltin;
+	int cmd_flag;
+	int execcmd;
+	int status;
+	char **nargv;
+	int vflags;
+	int vlocal;
+
+	errlinno = lineno = cmd->ncmd.linno;
+	if (funcline)
+		lineno -= funcline - 1;
+
+	/* First expand the arguments. */
+	TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
+	file_stop = parsefile;
+	back_exitstatus = 0;
+
+	cmdentry.cmdtype = CMDBUILTIN;
+	cmdentry.u.cmd = &bltin;
+	varlist.lastp = &varlist.list;
+	*varlist.lastp = NULL;
+	arglist.lastp = &arglist.list;
+	*arglist.lastp = NULL;
+
+	cmd_flag = 0;
+	execcmd = 0;
+	spclbltin = -1;
+	vflags = 0;
+	vlocal = 0;
+	path = NULL;
+
+	argc = 0;
+	argp = cmd->ncmd.args;
+	if ((osp = fill_arglist(&arglist, &argp))) {
+		int pseudovarflag = 0;
+
+		for (;;) {
+			find_command(arglist.list->text, &cmdentry,
+				     cmd_flag | DO_REGBLTIN, pathval());
+
+			vlocal++;
+
+			/* implement bltin and command here */
+			if (cmdentry.cmdtype != CMDBUILTIN)
+				break;
+
+			pseudovarflag = cmdentry.u.cmd->flags & BUILTIN_ASSIGN;
+			if (likely(spclbltin < 0)) {
+				spclbltin =
+					cmdentry.u.cmd->flags &
+					BUILTIN_SPECIAL
+				;
+				vlocal = spclbltin ^ BUILTIN_SPECIAL;
+			}
+			execcmd = cmdentry.u.cmd == EXECCMD;
+			if (likely(cmdentry.u.cmd != COMMANDCMD))
+				break;
+
+			cmd_flag = parse_command_args(&arglist, &argp, &path);
+			if (!cmd_flag)
+				break;
+		}
+
+		for (; argp; argp = argp->narg.next)
+			expandarg(argp, &arglist,
+				  pseudovarflag &&
+				  isassignment(argp->narg.text) ?
+				  EXP_VARTILDE : EXP_FULL | EXP_TILDE);
+
+		for (sp = arglist.list; sp; sp = sp->next)
+			argc++;
+
+		if (execcmd && argc > 1)
+			vflags = VEXPORT;
+	}
+
+	localvar_stop = pushlocalvars(vlocal);
+
+	/* Reserve one extra spot at the front for shellexec. */
+	nargv = stalloc(sizeof (char *) * (argc + 2));
+	argv = ++nargv;
+	for (sp = arglist.list ; sp ; sp = sp->next) {
+		TRACE(("evalcommand arg: %s\n", sp->text));
+		*nargv++ = sp->text;
+	}
+	*nargv = NULL;
+
+	lastarg = NULL;
+	if (iflag && funcline == 0 && argc > 0)
+		lastarg = nargv[-1];
+
+	preverrout.fd = 2;
+	expredir(cmd->ncmd.redirect);
+	redir_stop = pushredir(cmd->ncmd.redirect);
+	status = redirectsafe(cmd->ncmd.redirect, REDIR_PUSH|REDIR_SAVEFD2);
+
+	if (unlikely(status)) {
+bail:
+		exitstatus = status;
+
+		/* We have a redirection error. */
+		if (spclbltin > 0)
+			exraise(EXERROR);
+
+		goto out;
+	}
+
+	for (argp = cmd->ncmd.assign; argp; argp = argp->narg.next) {
+		struct strlist **spp;
+
+		spp = varlist.lastp;
+		expandarg(argp, &varlist, EXP_VARTILDE);
+
+		if (vlocal)
+			mklocal((*spp)->text, VEXPORT);
+		else
+			setvareq((*spp)->text, vflags);
+	}
+
+	/* Print the command if xflag is set. */
+	if (xflag) {
+		struct output *out;
+		int sep;
+
+		out = &preverrout;
+		outstr(expandstr(ps4val()), out);
+		sep = 0;
+		sep = eprintlist(out, varlist.list, sep);
+		eprintlist(out, osp, sep);
+		outcslow('\n', out);
+#ifdef FLUSHERR
+		flushout(out);
+#endif
+	}
+
+	/* Now locate the command. */
+	if (cmdentry.cmdtype != CMDBUILTIN ||
+	    !(cmdentry.u.cmd->flags & BUILTIN_REGULAR)) {
+		path = unlikely(path) ? path : pathval();
+		find_command(argv[0], &cmdentry, cmd_flag | DO_ERR, path);
+	}
+
+	jp = NULL;
+
+	/* Execute the command. */
+	switch (cmdentry.cmdtype) {
+	case CMDUNKNOWN:
+		status = 127;
+#ifdef FLUSHERR
+		flushout(&errout);
+#endif
+		goto bail;
+
+	default:
+		/* Fork off a child process if necessary. */
+		if (!(flags & EV_EXIT) || have_traps()) {
+			INTOFF;
+			jp = vforkexec(cmd, argv, path, cmdentry.u.index);
+			break;
+		}
+		shellexec(argv, path, cmdentry.u.index);
+		/* NOTREACHED */
+
+	case CMDBUILTIN:
+		if (evalbltin(cmdentry.u.cmd, argc, argv, flags) &&
+		    !(exception == EXERROR && spclbltin <= 0)) {
+raise:
+			longjmp(handler->loc, 1);
+		}
+		break;
+
+	case CMDFUNCTION:
+		if (evalfun(cmdentry.u.func, argc, argv, flags))
+			goto raise;
+		break;
+	}
+
+	status = waitforjob(jp);
+	FORCEINTON;
+
+out:
+	if (cmd->ncmd.redirect)
+		popredir(execcmd);
+	unwindredir(redir_stop);
+	unwindfiles(file_stop);
+	unwindlocalvars(localvar_stop);
+	if (lastarg)
+		/* dsl: I think this is intended to be used to support
+		 * '_' in 'vi' command mode during line editing...
+		 * However I implemented that within libedit itself.
+		 */
+		setvar("_", lastarg, 0);
+
+	return status;
+}
+
+STATIC int
+evalbltin(const struct builtincmd *cmd, int argc, char **argv, int flags)
+{
+	char *volatile savecmdname;
+	struct jmploc *volatile savehandler;
+	struct jmploc jmploc;
+	int status;
+	int i;
+
+	savecmdname = commandname;
+	savehandler = handler;
+	if ((i = setjmp(jmploc.loc)))
+		goto cmddone;
+	handler = &jmploc;
+	commandname = argv[0];
+	argptr = argv + 1;
+	optptr = NULL;			/* initialize nextopt */
+	if (cmd == EVALCMD)
+		status = evalcmd(argc, argv, flags);
+	else
+		status = (*cmd->builtin)(argc, argv);
+	flushall();
+	if (outerr(out1))
+		sh_warnx("%s: I/O error", commandname);
+	status |= outerr(out1);
+	exitstatus = status;
+cmddone:
+	freestdout();
+	commandname = savecmdname;
+	handler = savehandler;
+
+	return i;
+}
+
+STATIC int
+evalfun(struct funcnode *func, int argc, char **argv, int flags)
+{
+	volatile struct shparam saveparam;
+	struct jmploc *volatile savehandler;
+	struct jmploc jmploc;
+	int e;
+	int savefuncline;
+	int saveloopnest;
+
+	saveparam = shellparam;
+	savefuncline = funcline;
+	saveloopnest = loopnest;
+	savehandler = handler;
+	if ((e = setjmp(jmploc.loc))) {
+		goto funcdone;
+	}
+	INTOFF;
+	handler = &jmploc;
+	shellparam.malloc = 0;
+	func->count++;
+	funcline = func->n.ndefun.linno;
+	loopnest = 0;
+	INTON;
+	shellparam.nparam = argc - 1;
+	shellparam.p = argv + 1;
+	shellparam.optind = 1;
+	shellparam.optoff = -1;
+	evaltree(func->n.ndefun.body, flags & EV_TESTED);
+funcdone:
+	INTOFF;
+	loopnest = saveloopnest;
+	funcline = savefuncline;
+	freefunc(func);
+	freeparam(&shellparam);
+	shellparam = saveparam;
+	handler = savehandler;
+	INTON;
+	evalskip &= ~(SKIPFUNC | SKIPFUNCDEF);
+	return e;
+}
+
+
+/*
+ * Search for a command.  This is called before we fork so that the
+ * location of the command will be available in the parent as well as
+ * the child.  The check for "goodname" is an overly conservative
+ * check that the name will not be subject to expansion.
+ */
+
+STATIC void
+prehash(union node *n)
+{
+	struct cmdentry entry;
+
+	if (n->type == NCMD && n->ncmd.args)
+		if (goodname(n->ncmd.args->narg.text))
+			find_command(n->ncmd.args->narg.text, &entry, 0,
+				     pathval());
+}
+
+
+
+/*
+ * Builtin commands.  Builtin commands whose functions are closely
+ * tied to evaluation are implemented here.
+ */
+
+/*
+ * No command given.
+ */
+
+STATIC int
+bltincmd(int argc, char **argv)
+{
+	/*
+	 * Preserve exitstatus of a previous possible redirection
+	 * as POSIX mandates
+	 */
+	return back_exitstatus;
+}
+
+
+/*
+ * Handle break and continue commands.  Break, continue, and return are
+ * all handled by setting the evalskip flag.  The evaluation routines
+ * above all check this flag, and if it is set they start skipping
+ * commands rather than executing them.  The variable skipcount is
+ * the number of loops to break/continue, or the number of function
+ * levels to return.  (The latter is always 1.)  It should probably
+ * be an error to break out of more loops than exist, but it isn't
+ * in the standard shell so we don't make it one here.
+ */
+
+int
+breakcmd(int argc, char **argv)
+{
+	int n = argc > 1 ? number(argv[1]) : 1;
+
+	if (n <= 0)
+		badnum(argv[1]);
+	if (n > loopnest)
+		n = loopnest;
+	if (n > 0) {
+		evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
+		skipcount = n;
+	}
+	return 0;
+}
+
+
+/*
+ * The return command.
+ */
+
+int
+returncmd(int argc, char **argv)
+{
+	int skip;
+	int status;
+
+	/*
+	 * If called outside a function, do what ksh does;
+	 * skip the rest of the file.
+	 */
+	if (argv[1]) {
+		skip = SKIPFUNC;
+		status = number(argv[1]);
+	} else {
+		skip = SKIPFUNCDEF;
+		status = exitstatus;
+	}
+	evalskip = skip;
+
+	return status;
+}
+
+
+int
+falsecmd(int argc, char **argv)
+{
+	return 1;
+}
+
+
+int
+truecmd(int argc, char **argv)
+{
+	return 0;
+}
+
+
+int
+execcmd(int argc, char **argv)
+{
+	if (argc > 1) {
+		iflag = 0;		/* exit on error */
+		mflag = 0;
+		optschanged();
+		shellexec(argv + 1, pathval(), 0);
+	}
+	return 0;
+}
+
+
+STATIC int
+eprintlist(struct output *out, struct strlist *sp, int sep)
+{
+	while (sp) {
+		const char *p;
+
+		p = " %s";
+		p += (1 - sep);
+		sep |= 1;
+		outfmt(out, p, sp->text);
+		sp = sp->next;
+	}
+
+	return sep;
+}
diff --git a/src/eval.h b/src/eval.h
new file mode 100644
index 00000000..63e7d865
--- /dev/null
+++ b/src/eval.h
@@ -0,0 +1,65 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)eval.h	8.2 (Berkeley) 5/4/95
+ */
+
+extern char *commandname;	/* currently executing command */
+extern int exitstatus;		/* exit status of last command */
+extern int back_exitstatus;	/* exit status of backquoted command */
+extern int savestatus;		/* exit status of last command outside traps */
+
+
+struct backcmd {		/* result of evalbackcmd */
+	int fd;			/* file descriptor to read from */
+	char *buf;		/* buffer */
+	int nleft;		/* number of chars in buffer */
+	struct job *jp;		/* job structure for command */
+};
+
+/* flags in argument to evaltree */
+#define EV_EXIT 01		/* exit after evaluating tree */
+#define EV_TESTED 02		/* exit status is checked; ignore -e flag */
+
+int evalstring(char *, int);
+union node;	/* BLETCH for ansi C */
+int evaltree(union node *, int);
+void evalbackcmd(union node *, struct backcmd *);
+
+extern int evalskip;
+
+/* reasons for skipping commands (see comment on breakcmd routine) */
+#define SKIPBREAK	(1 << 0)
+#define SKIPCONT	(1 << 1)
+#define SKIPFUNC	(1 << 2)
+#define SKIPFUNCDEF	(1 << 3)
diff --git a/src/exec.c b/src/exec.c
new file mode 100644
index 00000000..87354d49
--- /dev/null
+++ b/src/exec.c
@@ -0,0 +1,908 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+
+/*
+ * When commands are first encountered, they are entered in a hash table.
+ * This ensures that a full path search will not have to be done for them
+ * on each invocation.
+ *
+ * We should investigate converting to a linear search, even though that
+ * would make the command name "hash" a misnomer.
+ */
+
+#include "shell.h"
+#include "main.h"
+#include "nodes.h"
+#include "parser.h"
+#include "redir.h"
+#include "eval.h"
+#include "exec.h"
+#include "builtins.h"
+#include "var.h"
+#include "options.h"
+#include "output.h"
+#include "syntax.h"
+#include "memalloc.h"
+#include "error.h"
+#include "init.h"
+#include "mystring.h"
+#include "show.h"
+#include "jobs.h"
+#include "alias.h"
+#include "system.h"
+
+
+#define CMDTABLESIZE 31		/* should be prime */
+#define ARB 1			/* actual size determined at run time */
+
+
+
+struct tblentry {
+	struct tblentry *next;	/* next entry in hash chain */
+	union param param;	/* definition of builtin function */
+	short cmdtype;		/* index identifying command */
+	char rehash;		/* if set, cd done since entry created */
+	char cmdname[ARB];	/* name of command */
+};
+
+
+STATIC struct tblentry *cmdtable[CMDTABLESIZE];
+STATIC int builtinloc = -1;		/* index in path of %builtin, or -1 */
+
+
+STATIC void tryexec(char *, char **, char **);
+STATIC void printentry(struct tblentry *);
+STATIC void clearcmdentry(void);
+STATIC struct tblentry *cmdlookup(const char *, int);
+STATIC void delete_cmd_entry(void);
+STATIC void addcmdentry(char *, struct cmdentry *);
+STATIC int describe_command(struct output *, char *, const char *, int);
+
+
+/*
+ * Exec a program.  Never returns.  If you change this routine, you may
+ * have to change the find_command routine as well.
+ */
+
+void
+shellexec(char **argv, const char *path, int idx)
+{
+	char *cmdname;
+	int e;
+	char **envp;
+	int exerrno;
+
+	envp = environment();
+	if (strchr(argv[0], '/') != NULL) {
+		tryexec(argv[0], argv, envp);
+		e = errno;
+	} else {
+		e = ENOENT;
+		while (padvance(&path, argv[0]) >= 0) {
+			cmdname = stackblock();
+			if (--idx < 0 && pathopt == NULL) {
+				tryexec(cmdname, argv, envp);
+				if (errno != ENOENT && errno != ENOTDIR)
+					e = errno;
+			}
+		}
+	}
+
+	/* Map to POSIX errors */
+	switch (e) {
+	default:
+		exerrno = 126;
+		break;
+	case ELOOP:
+	case ENAMETOOLONG:
+	case ENOENT:
+	case ENOTDIR:
+		exerrno = 127;
+		break;
+	}
+	exitstatus = exerrno;
+	TRACE(("shellexec failed for %s, errno %d, suppressint %d\n",
+		argv[0], e, suppressint ));
+	exerror(EXEND, "%s: %s", argv[0], errmsg(e, E_EXEC));
+	/* NOTREACHED */
+}
+
+
+STATIC void
+tryexec(char *cmd, char **argv, char **envp)
+{
+	char *const path_bshell = _PATH_BSHELL;
+
+repeat:
+#ifdef SYSV
+	do {
+		execve(cmd, argv, envp);
+	} while (errno == EINTR);
+#else
+	execve(cmd, argv, envp);
+#endif
+	if (cmd != path_bshell && errno == ENOEXEC) {
+		*argv-- = cmd;
+		*argv = cmd = path_bshell;
+		goto repeat;
+	}
+}
+
+static const char *legal_pathopt(const char *opt, const char *term, int magic)
+{
+	switch (magic) {
+	case 0:
+		opt = NULL;
+		break;
+
+	case 1:
+		opt = prefix(opt, "builtin") ?: prefix(opt, "func");
+		break;
+
+	default:
+		opt += strcspn(opt, term);
+		break;
+	}
+
+	if (opt && *opt == '%')
+		opt++;
+
+	return opt;
+}
+
+/*
+ * Do a path search.  The variable path (passed by reference) should be
+ * set to the start of the path before the first call; padvance will update
+ * this value as it proceeds.  Successive calls to padvance will return
+ * the possible path expansions in sequence.  If an option (indicated by
+ * a percent sign) appears in the path entry then the global variable
+ * pathopt will be set to point to it; otherwise pathopt will be set to
+ * NULL.
+ *
+ * If magic is 0 then pathopt recognition will be disabled.  If magic is
+ * 1 we shall recognise %builtin/%func.  Otherwise we shall accept any
+ * pathopt.
+ */
+
+const char *pathopt;
+
+int padvance_magic(const char **path, const char *name, int magic)
+{
+	const char *term = "%:";
+	const char *lpathopt;
+	const char *p;
+	char *q;
+	const char *start;
+	size_t qlen;
+	size_t len;
+
+	if (*path == NULL)
+		return -1;
+
+	lpathopt = NULL;
+	start = *path;
+
+	if (*start == '%' && (p = legal_pathopt(start + 1, term, magic))) {
+		lpathopt = start + 1;
+		start = p;
+		term = ":";
+	}
+
+	len = strcspn(start, term);
+	p = start + len;
+
+	if (*p == '%') {
+		size_t extra = strchrnul(p, ':') - p;
+
+		if (legal_pathopt(p + 1, term, magic))
+			lpathopt = p + 1;
+		else
+			len += extra;
+
+		p += extra;
+	}
+
+	pathopt = lpathopt;
+	*path = *p == ':' ? p + 1 : NULL;
+
+	/* "2" is for '/' and '\0' */
+	qlen = len + strlen(name) + 2;
+	q = growstackto(qlen);
+
+	if (likely(len)) {
+		q = mempcpy(q, start, len);
+		*q++ = '/';
+	}
+	strcpy(q, name);
+
+	return qlen;
+}
+
+
+
+/*** Command hashing code ***/
+
+
+int
+hashcmd(int argc, char **argv)
+{
+	struct tblentry **pp;
+	struct tblentry *cmdp;
+	int c;
+	struct cmdentry entry;
+	char *name;
+
+	while ((c = nextopt("r")) != '\0') {
+		clearcmdentry();
+		return 0;
+	}
+	if (*argptr == NULL) {
+		for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
+			for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
+				if (cmdp->cmdtype == CMDNORMAL)
+					printentry(cmdp);
+			}
+		}
+		return 0;
+	}
+	c = 0;
+	while ((name = *argptr) != NULL) {
+		if ((cmdp = cmdlookup(name, 0)) &&
+		    (cmdp->cmdtype == CMDNORMAL ||
+		     (cmdp->cmdtype == CMDBUILTIN &&
+		      !(cmdp->param.cmd->flags & BUILTIN_REGULAR) &&
+		      builtinloc > 0)))
+			delete_cmd_entry();
+		find_command(name, &entry, DO_ERR, pathval());
+		if (entry.cmdtype == CMDUNKNOWN)
+			c = 1;
+		argptr++;
+	}
+	return c;
+}
+
+
+STATIC void
+printentry(struct tblentry *cmdp)
+{
+	int idx;
+	const char *path;
+	char *name;
+
+	idx = cmdp->param.index;
+	path = pathval();
+	do {
+		padvance(&path, cmdp->cmdname);
+	} while (--idx >= 0);
+	name = stackblock();
+	out1str(name);
+	out1fmt(snlfmt, cmdp->rehash ? "*" : nullstr);
+}
+
+
+
+/*
+ * Resolve a command name.  If you change this routine, you may have to
+ * change the shellexec routine as well.
+ */
+
+void
+find_command(char *name, struct cmdentry *entry, int act, const char *path)
+{
+	struct tblentry *cmdp;
+	int idx;
+	int prev;
+	char *fullname;
+	struct stat64 statb;
+	int e;
+	int updatetbl;
+	struct builtincmd *bcmd;
+	int len;
+
+	/* If name contains a slash, don't use PATH or hash table */
+	if (strchr(name, '/') != NULL) {
+		entry->u.index = -1;
+		if (act & DO_ABS) {
+			while (stat64(name, &statb) < 0) {
+#ifdef SYSV
+				if (errno == EINTR)
+					continue;
+#endif
+				entry->cmdtype = CMDUNKNOWN;
+				return;
+			}
+		}
+		entry->cmdtype = CMDNORMAL;
+		return;
+	}
+
+	updatetbl = (path == pathval());
+	if (!updatetbl)
+		act |= DO_ALTPATH;
+
+	/* If name is in the table, check answer will be ok */
+	if ((cmdp = cmdlookup(name, 0)) != NULL) {
+		int bit;
+
+		switch (cmdp->cmdtype) {
+		default:
+#if DEBUG
+			abort();
+#endif
+		case CMDNORMAL:
+			bit = DO_ALTPATH | DO_REGBLTIN;
+			break;
+		case CMDFUNCTION:
+			bit = DO_NOFUNC;
+			break;
+		case CMDBUILTIN:
+			bit = cmdp->param.cmd->flags & BUILTIN_REGULAR ?
+			      0 : DO_REGBLTIN;
+			break;
+		}
+		if (act & bit) {
+			if (act & bit & DO_REGBLTIN)
+				goto fail;
+
+			updatetbl = 0;
+			cmdp = NULL;
+		} else if (cmdp->rehash == 0)
+			/* if not invalidated by cd, we're done */
+			goto success;
+	}
+
+	/* If %builtin not in path, check for builtin next */
+	bcmd = find_builtin(name);
+	if (bcmd && ((bcmd->flags & BUILTIN_REGULAR) | (act & DO_ALTPATH) |
+		     (builtinloc <= 0)))
+		goto builtin_success;
+
+	if (act & DO_REGBLTIN)
+		goto fail;
+
+	/* We have to search path. */
+	prev = -1;		/* where to start */
+	if (cmdp && cmdp->rehash) {	/* doing a rehash */
+		if (cmdp->cmdtype == CMDBUILTIN)
+			prev = builtinloc;
+		else
+			prev = cmdp->param.index;
+	}
+
+	e = ENOENT;
+	idx = -1;
+loop:
+	while ((len = padvance(&path, name)) >= 0) {
+		const char *lpathopt = pathopt;
+
+		fullname = stackblock();
+		idx++;
+		if (lpathopt) {
+			if (*lpathopt == 'b') {
+				if (bcmd)
+					goto builtin_success;
+				continue;
+			} else if (!(act & DO_NOFUNC)) {
+				/* handled below */
+			} else {
+				/* ignore unimplemented options */
+				continue;
+			}
+		}
+		/* if rehash, don't redo absolute path names */
+		if (fullname[0] == '/' && idx <= prev) {
+			if (idx < prev)
+				continue;
+			TRACE(("searchexec \"%s\": no change\n", name));
+			goto success;
+		}
+		while (stat64(fullname, &statb) < 0) {
+#ifdef SYSV
+			if (errno == EINTR)
+				continue;
+#endif
+			if (errno != ENOENT && errno != ENOTDIR)
+				e = errno;
+			goto loop;
+		}
+		e = EACCES;	/* if we fail, this will be the error */
+		if (!S_ISREG(statb.st_mode))
+			continue;
+		if (lpathopt) {		/* this is a %func directory */
+			stalloc(len);
+			readcmdfile(fullname);
+			if ((cmdp = cmdlookup(name, 0)) == NULL ||
+			    cmdp->cmdtype != CMDFUNCTION)
+				sh_error("%s not defined in %s", name,
+					 fullname);
+			stunalloc(fullname);
+			goto success;
+		}
+#ifdef notdef
+		/* XXX this code stops root executing stuff, and is buggy
+		   if you need a group from the group list. */
+		if (statb.st_uid == geteuid()) {
+			if ((statb.st_mode & 0100) == 0)
+				goto loop;
+		} else if (statb.st_gid == getegid()) {
+			if ((statb.st_mode & 010) == 0)
+				goto loop;
+		} else {
+			if ((statb.st_mode & 01) == 0)
+				goto loop;
+		}
+#endif
+		TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
+		if (!updatetbl) {
+			entry->cmdtype = CMDNORMAL;
+			entry->u.index = idx;
+			return;
+		}
+		INTOFF;
+		cmdp = cmdlookup(name, 1);
+		cmdp->cmdtype = CMDNORMAL;
+		cmdp->param.index = idx;
+		INTON;
+		goto success;
+	}
+
+	/* We failed.  If there was an entry for this command, delete it */
+	if (cmdp && updatetbl)
+		delete_cmd_entry();
+	if (act & DO_ERR)
+		sh_warnx("%s: %s", name, errmsg(e, E_EXEC));
+fail:
+	entry->cmdtype = CMDUNKNOWN;
+	return;
+
+builtin_success:
+	if (!updatetbl) {
+		entry->cmdtype = CMDBUILTIN;
+		entry->u.cmd = bcmd;
+		return;
+	}
+	INTOFF;
+	cmdp = cmdlookup(name, 1);
+	cmdp->cmdtype = CMDBUILTIN;
+	cmdp->param.cmd = bcmd;
+	INTON;
+success:
+	cmdp->rehash = 0;
+	entry->cmdtype = cmdp->cmdtype;
+	entry->u = cmdp->param;
+}
+
+
+
+/*
+ * Search the table of builtin commands.
+ */
+
+struct builtincmd *
+find_builtin(const char *name)
+{
+	struct builtincmd *bp;
+
+	bp = bsearch(
+		&name, builtincmd, NUMBUILTINS, sizeof(struct builtincmd),
+		pstrcmp
+	);
+	return bp;
+}
+
+
+
+/*
+ * Called when a cd is done.  Marks all commands so the next time they
+ * are executed they will be rehashed.
+ */
+
+void
+hashcd(void)
+{
+	struct tblentry **pp;
+	struct tblentry *cmdp;
+
+	for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
+		for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
+			if (cmdp->cmdtype == CMDNORMAL || (
+				cmdp->cmdtype == CMDBUILTIN &&
+				!(cmdp->param.cmd->flags & BUILTIN_REGULAR) &&
+				builtinloc > 0
+			))
+				cmdp->rehash = 1;
+		}
+	}
+}
+
+
+
+/*
+ * Fix command hash table when PATH changed.
+ * Called before PATH is changed.  The argument is the new value of PATH;
+ * pathval() still returns the old value at this point.
+ * Called with interrupts off.
+ */
+
+void
+changepath(const char *newval)
+{
+	const char *new;
+	int idx;
+	int bltin;
+
+	new = newval;
+	idx = 0;
+	bltin = -1;
+	for (;;) {
+		if (*new == '%' && prefix(new + 1, "builtin")) {
+			bltin = idx;
+			break;
+		}
+		new = strchr(new, ':');
+		if (!new)
+			break;
+		idx++;
+		new++;
+	}
+	builtinloc = bltin;
+	clearcmdentry();
+}
+
+
+/*
+ * Clear out command entries.  The argument specifies the first entry in
+ * PATH which has changed.
+ */
+
+STATIC void
+clearcmdentry(void)
+{
+	struct tblentry **tblp;
+	struct tblentry **pp;
+	struct tblentry *cmdp;
+
+	INTOFF;
+	for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
+		pp = tblp;
+		while ((cmdp = *pp) != NULL) {
+			if (cmdp->cmdtype == CMDNORMAL ||
+			    (cmdp->cmdtype == CMDBUILTIN &&
+			     !(cmdp->param.cmd->flags & BUILTIN_REGULAR) &&
+			     builtinloc > 0)) {
+				*pp = cmdp->next;
+				ckfree(cmdp);
+			} else {
+				pp = &cmdp->next;
+			}
+		}
+	}
+	INTON;
+}
+
+
+
+/*
+ * Locate a command in the command hash table.  If "add" is nonzero,
+ * add the command to the table if it is not already present.  The
+ * variable "lastcmdentry" is set to point to the address of the link
+ * pointing to the entry, so that delete_cmd_entry can delete the
+ * entry.
+ *
+ * Interrupts must be off if called with add != 0.
+ */
+
+struct tblentry **lastcmdentry;
+
+
+STATIC struct tblentry *
+cmdlookup(const char *name, int add)
+{
+	unsigned int hashval;
+	const char *p;
+	struct tblentry *cmdp;
+	struct tblentry **pp;
+
+	p = name;
+	hashval = (unsigned char)*p << 4;
+	while (*p)
+		hashval += (unsigned char)*p++;
+	hashval &= 0x7FFF;
+	pp = &cmdtable[hashval % CMDTABLESIZE];
+	for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
+		if (equal(cmdp->cmdname, name))
+			break;
+		pp = &cmdp->next;
+	}
+	if (add && cmdp == NULL) {
+		cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB
+					+ strlen(name) + 1);
+		cmdp->next = NULL;
+		cmdp->cmdtype = CMDUNKNOWN;
+		strcpy(cmdp->cmdname, name);
+	}
+	lastcmdentry = pp;
+	return cmdp;
+}
+
+/*
+ * Delete the command entry returned on the last lookup.
+ */
+
+STATIC void
+delete_cmd_entry(void)
+{
+	struct tblentry *cmdp;
+
+	INTOFF;
+	cmdp = *lastcmdentry;
+	*lastcmdentry = cmdp->next;
+	if (cmdp->cmdtype == CMDFUNCTION)
+		freefunc(cmdp->param.func);
+	ckfree(cmdp);
+	INTON;
+}
+
+
+
+#ifdef notdef
+void
+getcmdentry(char *name, struct cmdentry *entry)
+{
+	struct tblentry *cmdp = cmdlookup(name, 0);
+
+	if (cmdp) {
+		entry->u = cmdp->param;
+		entry->cmdtype = cmdp->cmdtype;
+	} else {
+		entry->cmdtype = CMDUNKNOWN;
+		entry->u.index = 0;
+	}
+}
+#endif
+
+
+/*
+ * Add a new command entry, replacing any existing command entry for
+ * the same name - except special builtins.
+ */
+
+STATIC void
+addcmdentry(char *name, struct cmdentry *entry)
+{
+	struct tblentry *cmdp;
+
+	cmdp = cmdlookup(name, 1);
+	if (cmdp->cmdtype == CMDFUNCTION) {
+		freefunc(cmdp->param.func);
+	}
+	cmdp->cmdtype = entry->cmdtype;
+	cmdp->param = entry->u;
+	cmdp->rehash = 0;
+}
+
+
+/*
+ * Define a shell function.
+ */
+
+void
+defun(union node *func)
+{
+	struct cmdentry entry;
+
+	INTOFF;
+	entry.cmdtype = CMDFUNCTION;
+	entry.u.func = copyfunc(func);
+	addcmdentry(func->ndefun.text, &entry);
+	INTON;
+}
+
+
+/*
+ * Delete a function if it exists.
+ */
+
+void
+unsetfunc(const char *name)
+{
+	struct tblentry *cmdp;
+
+	if ((cmdp = cmdlookup(name, 0)) != NULL &&
+	    cmdp->cmdtype == CMDFUNCTION)
+		delete_cmd_entry();
+}
+
+/*
+ * Locate and print what a word is...
+ */
+
+int
+typecmd(int argc, char **argv)
+{
+	int i;
+	int err = 0;
+
+	for (i = 1; i < argc; i++) {
+		err |= describe_command(out1, argv[i], NULL, 1);
+	}
+	return err;
+}
+
+STATIC int
+describe_command(out, command, path, verbose)
+	struct output *out;
+	char *command;
+	const char *path;
+	int verbose;
+{
+	struct cmdentry entry;
+	struct tblentry *cmdp;
+	const struct alias *ap;
+
+	if (verbose) {
+		outstr(command, out);
+	}
+
+	/* First look at the keywords */
+	if (findkwd(command)) {
+		outstr(verbose ? " is a shell keyword" : command, out);
+		goto out;
+	}
+
+	/* Then look at the aliases */
+	if ((ap = lookupalias(command, 0)) != NULL) {
+		if (verbose) {
+			outfmt(out, " is an alias for %s", ap->val);
+		} else {
+			outstr("alias ", out);
+			printalias(ap);
+			return 0;
+		}
+		goto out;
+	}
+
+	/* Then if the standard search path is used, check if it is
+	 * a tracked alias.
+	 */
+	if (path == NULL) {
+		path = pathval();
+		cmdp = cmdlookup(command, 0);
+	} else {
+		cmdp = NULL;
+	}
+
+	if (cmdp != NULL) {
+		entry.cmdtype = cmdp->cmdtype;
+		entry.u = cmdp->param;
+	} else {
+		/* Finally use brute force */
+		find_command(command, &entry, DO_ABS, path);
+	}
+
+	switch (entry.cmdtype) {
+	case CMDNORMAL: {
+		int j = entry.u.index;
+		char *p;
+		if (j == -1) {
+			p = command;
+		} else {
+			do {
+				padvance(&path, command);
+			} while (--j >= 0);
+			p = stackblock();
+		}
+		if (verbose) {
+			outfmt(
+				out, " is%s %s",
+				cmdp ? " a tracked alias for" : nullstr, p
+			);
+		} else {
+			outstr(p, out);
+		}
+		break;
+	}
+
+	case CMDFUNCTION:
+		if (verbose) {
+			outstr(" is a shell function", out);
+		} else {
+			outstr(command, out);
+		}
+		break;
+
+	case CMDBUILTIN:
+		if (verbose) {
+			outfmt(
+				out, " is a %sshell builtin",
+				entry.u.cmd->flags & BUILTIN_SPECIAL ?
+					"special " : nullstr
+			);
+		} else {
+			outstr(command, out);
+		}
+		break;
+
+	default:
+		if (verbose) {
+			outstr(": not found\n", out);
+		}
+		return 127;
+	}
+
+out:
+	outc('\n', out);
+	return 0;
+}
+
+int
+commandcmd(argc, argv)
+	int argc;
+	char **argv;
+{
+	char *cmd;
+	int c;
+	enum {
+		VERIFY_BRIEF = 1,
+		VERIFY_VERBOSE = 2,
+	} verify = 0;
+	const char *path = NULL;
+
+	while ((c = nextopt("pvV")) != '\0')
+		if (c == 'V')
+			verify |= VERIFY_VERBOSE;
+		else if (c == 'v')
+			verify |= VERIFY_BRIEF;
+#ifdef DEBUG
+		else if (c != 'p')
+			abort();
+#endif
+		else
+			path = defpath;
+
+	cmd = *argptr;
+	if (verify && cmd)
+		return describe_command(out1, cmd, path, verify - VERIFY_BRIEF);
+
+	return 0;
+}
diff --git a/src/exec.h b/src/exec.h
new file mode 100644
index 00000000..423b07e6
--- /dev/null
+++ b/src/exec.h
@@ -0,0 +1,84 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)exec.h	8.3 (Berkeley) 6/8/95
+ */
+
+/* values of cmdtype */
+#define CMDUNKNOWN	-1	/* no entry in table for command */
+#define CMDNORMAL	0	/* command is an executable program */
+#define CMDFUNCTION	1	/* command is a shell function */
+#define CMDBUILTIN	2	/* command is a shell builtin */
+
+
+struct cmdentry {
+	int cmdtype;
+	union param {
+		int index;
+		const struct builtincmd *cmd;
+		struct funcnode *func;
+	} u;
+};
+
+
+/* action to find_command() */
+#define DO_ERR		0x01	/* prints errors */
+#define DO_ABS		0x02	/* checks absolute paths */
+#define DO_NOFUNC	0x04	/* don't return shell functions, for command */
+#define DO_ALTPATH	0x08	/* using alternate path */
+#define DO_REGBLTIN	0x10	/* regular built-ins and functions only */
+
+union node;
+
+extern const char *pathopt;	/* set by padvance */
+
+void shellexec(char **, const char *, int)
+    __attribute__((__noreturn__));
+int padvance_magic(const char **path, const char *name, int magic);
+int hashcmd(int, char **);
+void find_command(char *, struct cmdentry *, int, const char *);
+struct builtincmd *find_builtin(const char *);
+void hashcd(void);
+void changepath(const char *);
+#ifdef notdef
+void getcmdentry(char *, struct cmdentry *);
+#endif
+void defun(union node *);
+void unsetfunc(const char *);
+int typecmd(int, char **);
+int commandcmd(int, char **);
+
+static inline int padvance(const char **path, const char *name)
+{
+	return padvance_magic(path, name, 1);
+}
diff --git a/src/expand.c b/src/expand.c
new file mode 100644
index 00000000..1730670e
--- /dev/null
+++ b/src/expand.c
@@ -0,0 +1,1753 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <unistd.h>
+#ifdef HAVE_GETPWNAM
+#include <pwd.h>
+#endif
+#include <stdlib.h>
+#include <stdio.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <string.h>
+#ifdef HAVE_FNMATCH
+#include <fnmatch.h>
+#endif
+#ifdef HAVE_GLOB
+#include <glob.h>
+#endif
+#include <ctype.h>
+#include <stdbool.h>
+
+/*
+ * Routines to expand arguments to commands.  We have to deal with
+ * backquotes, shell variables, and file metacharacters.
+ */
+
+#include "shell.h"
+#include "main.h"
+#include "nodes.h"
+#include "eval.h"
+#include "expand.h"
+#include "syntax.h"
+#include "parser.h"
+#include "jobs.h"
+#include "options.h"
+#include "var.h"
+#include "output.h"
+#include "memalloc.h"
+#include "error.h"
+#include "mystring.h"
+#include "show.h"
+#include "system.h"
+
+/*
+ * _rmescape() flags
+ */
+#define RMESCAPE_ALLOC	0x1	/* Allocate a new string */
+#define RMESCAPE_GLOB	0x2	/* Add backslashes for glob */
+#define RMESCAPE_GROW	0x8	/* Grow strings instead of stalloc */
+#define RMESCAPE_HEAP	0x10	/* Malloc strings instead of stalloc */
+
+/* Add CTLESC when necessary. */
+#define QUOTES_ESC	(EXP_FULL | EXP_CASE)
+
+/*
+ * Structure specifying which parts of the string should be searched
+ * for IFS characters.
+ */
+
+struct ifsregion {
+	struct ifsregion *next;	/* next region in list */
+	int begoff;		/* offset of start of region */
+	int endoff;		/* offset of end of region */
+	int nulonly;		/* search for nul bytes only */
+};
+
+/* output of current string */
+static char *expdest;
+/* list of back quote expressions */
+static struct nodelist *argbackq;
+/* first struct in list of ifs regions */
+static struct ifsregion ifsfirst;
+/* last struct in list */
+static struct ifsregion *ifslastp;
+/* holds expanded arg list */
+static struct arglist exparg;
+
+static char *argstr(char *p, int flag);
+static char *exptilde(char *startp, int flag);
+static char *expari(char *start, int flag);
+STATIC void expbackq(union node *, int);
+STATIC char *evalvar(char *, int);
+static size_t strtodest(const char *p, int flags);
+static size_t memtodest(const char *p, size_t len, int flags);
+STATIC ssize_t varvalue(char *, int, int, int);
+STATIC void expandmeta(struct strlist *);
+#ifdef HAVE_GLOB
+STATIC void addglob(const glob_t *);
+#else
+STATIC void expmeta(char *, unsigned, unsigned);
+STATIC struct strlist *expsort(struct strlist *);
+STATIC struct strlist *msort(struct strlist *, int);
+#endif
+STATIC void addfname(char *);
+STATIC int patmatch(char *, const char *);
+#ifndef HAVE_FNMATCH
+STATIC int pmatch(const char *, const char *);
+#else
+#define pmatch(a, b) !fnmatch((a), (b), 0)
+#endif
+static size_t cvtnum(intmax_t num, int flags);
+STATIC size_t esclen(const char *, const char *);
+STATIC char *scanleft(char *, char *, char *, char *, int, int);
+STATIC char *scanright(char *, char *, char *, char *, int, int);
+STATIC void varunset(const char *, const char *, const char *, int)
+	__attribute__((__noreturn__));
+
+
+/*
+ * Prepare a pattern for a glob(3) call.
+ *
+ * Returns an stalloced string.
+ */
+
+STATIC inline char *
+preglob(const char *pattern, int flag) {
+	flag |= RMESCAPE_GLOB;
+	return _rmescapes((char *)pattern, flag);
+}
+
+
+STATIC size_t
+esclen(const char *start, const char *p) {
+	size_t esc = 0;
+
+	while (p > start && *--p == (char)CTLESC) {
+		esc++;
+	}
+	return esc;
+}
+
+
+static inline const char *getpwhome(const char *name)
+{
+#ifdef HAVE_GETPWNAM
+	struct passwd *pw = getpwnam(name);
+	return pw ? pw->pw_dir : 0;
+#else
+	return 0;
+#endif
+}
+
+
+/*
+ * Perform variable substitution and command substitution on an argument,
+ * placing the resulting list of arguments in arglist.  If EXP_FULL is true,
+ * perform splitting and file name expansion.  When arglist is NULL, perform
+ * here document expansion.
+ */
+
+void
+expandarg(union node *arg, struct arglist *arglist, int flag)
+{
+	struct strlist *sp;
+	char *p;
+
+	argbackq = arg->narg.backquote;
+	STARTSTACKSTR(expdest);
+	argstr(arg->narg.text, flag);
+	if (arglist == NULL) {
+		/* here document expanded */
+		goto out;
+	}
+	p = grabstackstr(expdest);
+	exparg.lastp = &exparg.list;
+	/*
+	 * TODO - EXP_REDIR
+	 */
+	if (flag & EXP_FULL) {
+		ifsbreakup(p, -1, &exparg);
+		*exparg.lastp = NULL;
+		exparg.lastp = &exparg.list;
+		expandmeta(exparg.list);
+	} else {
+		sp = (struct strlist *)stalloc(sizeof (struct strlist));
+		sp->text = p;
+		*exparg.lastp = sp;
+		exparg.lastp = &sp->next;
+	}
+	*exparg.lastp = NULL;
+	if (exparg.list) {
+		*arglist->lastp = exparg.list;
+		arglist->lastp = exparg.lastp;
+	}
+
+out:
+	ifsfree();
+}
+
+
+
+/*
+ * Perform variable and command substitution.  If EXP_FULL is set, output CTLESC
+ * characters to allow for further processing.  Otherwise treat
+ * $@ like $* since no splitting will be performed.
+ */
+
+static char *argstr(char *p, int flag)
+{
+	static const char spclchars[] = {
+		'=',
+		':',
+		CTLQUOTEMARK,
+		CTLENDVAR,
+		CTLESC,
+		CTLVAR,
+		CTLBACKQ,
+		CTLARI,
+		CTLENDARI,
+		0
+	};
+	const char *reject = spclchars;
+	int c;
+	int breakall = (flag & (EXP_WORD | EXP_QUOTED)) == EXP_WORD;
+	int inquotes;
+	size_t length;
+	int startloc;
+
+	reject += !!(flag & EXP_VARTILDE2);
+	reject += flag & EXP_VARTILDE ? 0 : 2;
+	inquotes = 0;
+	length = 0;
+	if (flag & EXP_TILDE) {
+		flag &= ~EXP_TILDE;
+tilde:
+		if (*p == '~')
+			p = exptilde(p, flag);
+	}
+start:
+	startloc = expdest - (char *)stackblock();
+	for (;;) {
+		int end;
+
+		length += strcspn(p + length, reject);
+		end = 0;
+		c = (signed char)p[length];
+		if (!(c & 0x80) || c == CTLENDARI || c == CTLENDVAR) {
+			/*
+			 * c == '=' || c == ':' || c == '\0' ||
+			 * c == CTLENDARI || c == CTLENDVAR
+			 */
+			length++;
+			/* c == '\0' || c == CTLENDARI || c == CTLENDVAR */
+			end = !!((c - 1) & 0x80);
+		}
+		if (length > 0 && !(flag & EXP_DISCARD)) {
+			int newloc;
+			char *q;
+
+			q = stnputs(p, length, expdest);
+			q[-1] &= end - 1;
+			expdest = q - (flag & EXP_WORD ? end : 0);
+			newloc = q - (char *)stackblock() - end;
+			if (breakall && !inquotes && newloc > startloc) {
+				recordregion(startloc, newloc, 0);
+			}
+			startloc = newloc;
+		}
+		p += length + 1;
+		length = 0;
+
+		if (end)
+			break;
+
+		switch (c) {
+		case '=':
+			flag |= EXP_VARTILDE2;
+			reject++;
+			/* fall through */
+		case ':':
+			/*
+			 * sort of a hack - expand tildes in variable
+			 * assignments (after the first '=' and after ':'s).
+			 */
+			if (*--p == '~') {
+				goto tilde;
+			}
+			continue;
+		case CTLQUOTEMARK:
+			/* "$@" syntax adherence hack */
+			if (!inquotes && !memcmp(p, dolatstr + 1,
+						 DOLATSTRLEN - 1)) {
+				p = evalvar(p + 1, flag | EXP_QUOTED) + 1;
+				goto start;
+			}
+			inquotes ^= EXP_QUOTED;
+addquote:
+			if (flag & QUOTES_ESC) {
+				p--;
+				length++;
+				startloc++;
+			}
+			break;
+		case CTLESC:
+			startloc++;
+			length++;
+			goto addquote;
+		case CTLVAR:
+			p = evalvar(p, flag | inquotes);
+			goto start;
+		case CTLBACKQ:
+			expbackq(argbackq->n, flag | inquotes);
+			goto start;
+		case CTLARI:
+			p = expari(p, flag | inquotes);
+			goto start;
+		}
+	}
+	return p - 1;
+}
+
+static char *exptilde(char *startp, int flag)
+{
+	signed char c;
+	char *name;
+	const char *home;
+	char *p;
+
+	p = startp;
+	name = p + 1;
+
+	while ((c = *++p) != '\0') {
+		switch(c) {
+		case CTLESC:
+			return (startp);
+		case CTLQUOTEMARK:
+			return (startp);
+		case ':':
+			if (flag & EXP_VARTILDE)
+				goto done;
+			break;
+		case '/':
+		case CTLENDVAR:
+			goto done;
+		}
+	}
+done:
+	if (flag & EXP_DISCARD)
+		goto out;
+	*p = '\0';
+	if (*name == '\0') {
+		home = lookupvar(homestr);
+	} else {
+		home = getpwhome(name);
+	}
+	*p = c;
+	if (!home)
+		goto lose;
+	strtodest(home, flag | EXP_QUOTED);
+out:
+	return (p);
+lose:
+	return (startp);
+}
+
+
+void 
+removerecordregions(int endoff)
+{
+	if (ifslastp == NULL)
+		return;
+
+	if (ifsfirst.endoff > endoff) {
+		while (ifsfirst.next != NULL) {
+			struct ifsregion *ifsp;
+			INTOFF;
+			ifsp = ifsfirst.next->next;
+			ckfree(ifsfirst.next);
+			ifsfirst.next = ifsp;
+			INTON;
+		}
+		if (ifsfirst.begoff > endoff)
+			ifslastp = NULL;
+		else {
+			ifslastp = &ifsfirst;
+			ifsfirst.endoff = endoff;
+		}
+		return;
+	}
+	
+	ifslastp = &ifsfirst;
+	while (ifslastp->next && ifslastp->next->begoff < endoff)
+		ifslastp=ifslastp->next;
+	while (ifslastp->next != NULL) {
+		struct ifsregion *ifsp;
+		INTOFF;
+		ifsp = ifslastp->next->next;
+		ckfree(ifslastp->next);
+		ifslastp->next = ifsp;
+		INTON;
+	}
+	if (ifslastp->endoff > endoff)
+		ifslastp->endoff = endoff;
+}
+
+
+/*
+ * Expand arithmetic expression.  Backup to start of expression,
+ * evaluate, place result in (backed up) result, adjust string position.
+ */
+static char *expari(char *start, int flag)
+{
+	struct stackmark sm;
+	int begoff;
+	int endoff;
+	int len;
+	intmax_t result;
+	char *p;
+
+	p = stackblock();
+	begoff = expdest - p;
+	p = argstr(start, flag & EXP_DISCARD);
+
+	if (flag & EXP_DISCARD)
+		goto out;
+
+	start = stackblock();
+	endoff = expdest - start;
+	start += begoff;
+	STADJUST(start - expdest, expdest);
+
+	removerecordregions(begoff);
+
+	if (likely(flag & QUOTES_ESC))
+		rmescapes(start);
+
+	pushstackmark(&sm, endoff);
+	result = arith(start);
+	popstackmark(&sm);
+
+	len = cvtnum(result, flag);
+
+	if (likely(!(flag & EXP_QUOTED)))
+		recordregion(begoff, begoff + len, 0);
+
+out:
+	return p;
+}
+
+
+/*
+ * Expand stuff in backwards quotes.
+ */
+
+STATIC void
+expbackq(union node *cmd, int flag)
+{
+	struct backcmd in;
+	int i;
+	char buf[128];
+	char *p;
+	char *dest;
+	int startloc;
+	struct stackmark smark;
+
+	if (flag & EXP_DISCARD)
+		goto out;
+
+	INTOFF;
+	startloc = expdest - (char *)stackblock();
+	pushstackmark(&smark, startloc);
+	evalbackcmd(cmd, (struct backcmd *) &in);
+	popstackmark(&smark);
+
+	p = in.buf;
+	i = in.nleft;
+	if (i == 0)
+		goto read;
+	for (;;) {
+		memtodest(p, i, flag);
+read:
+		if (in.fd < 0)
+			break;
+		do {
+			i = read(in.fd, buf, sizeof buf);
+		} while (i < 0 && errno == EINTR);
+		TRACE(("expbackq: read returns %d\n", i));
+		if (i <= 0)
+			break;
+		p = buf;
+	}
+
+	if (in.buf)
+		ckfree(in.buf);
+	if (in.fd >= 0) {
+		close(in.fd);
+		back_exitstatus = waitforjob(in.jp);
+	}
+	INTON;
+
+	/* Eat all trailing newlines */
+	dest = expdest;
+	for (; dest > ((char *)stackblock() + startloc) && dest[-1] == '\n';)
+		STUNPUTC(dest);
+	expdest = dest;
+
+	if (!(flag & EXP_QUOTED))
+		recordregion(startloc, dest - (char *)stackblock(), 0);
+	TRACE(("evalbackq: size=%d: \"%.*s\"\n",
+		(dest - (char *)stackblock()) - startloc,
+		(dest - (char *)stackblock()) - startloc,
+		stackblock() + startloc));
+
+out:
+	argbackq = argbackq->next;
+}
+
+
+STATIC char *
+scanleft(
+	char *startp, char *rmesc, char *rmescend, char *str, int quotes,
+	int zero
+) {
+	char *loc;
+	char *loc2;
+	char c;
+
+	loc = startp;
+	loc2 = rmesc;
+	do {
+		int match;
+		const char *s = loc2;
+		c = *loc2;
+		if (zero) {
+			*loc2 = '\0';
+			s = rmesc;
+		}
+		match = pmatch(str, s);
+		*loc2 = c;
+		if (match)
+			return loc;
+		if (quotes && *loc == (char)CTLESC)
+			loc++;
+		loc++;
+		loc2++;
+	} while (c);
+	return 0;
+}
+
+
+STATIC char *
+scanright(
+	char *startp, char *rmesc, char *rmescend, char *str, int quotes,
+	int zero
+) {
+	int esc = 0;
+	char *loc;
+	char *loc2;
+
+	for (loc = str - 1, loc2 = rmescend; loc >= startp; loc2--) {
+		int match;
+		char c = *loc2;
+		const char *s = loc2;
+		if (zero) {
+			*loc2 = '\0';
+			s = rmesc;
+		}
+		match = pmatch(str, s);
+		*loc2 = c;
+		if (match)
+			return loc;
+		loc--;
+		if (quotes) {
+			if (--esc < 0) {
+				esc = esclen(startp, loc);
+			}
+			if (esc % 2) {
+				esc--;
+				loc--;
+			}
+		}
+	}
+	return 0;
+}
+
+static char *subevalvar(char *start, char *str, int strloc, int startloc,
+			int varflags, int flag)
+{
+	int subtype = varflags & VSTYPE;
+	int quotes = flag & QUOTES_ESC;
+	char *startp;
+	char *loc;
+	long amount;
+	char *rmesc, *rmescend;
+	int zero;
+	char *(*scan)(char *, char *, char *, char *, int , int);
+	char *p;
+
+	p = argstr(start, (flag & EXP_DISCARD) | EXP_TILDE |
+			  (str ?  0 : EXP_CASE));
+	if (flag & EXP_DISCARD)
+		return p;
+
+	startp = stackblock() + startloc;
+
+	switch (subtype) {
+	case VSASSIGN:
+		setvar(str, startp, 0);
+
+		loc = startp;
+		goto out;
+
+	case VSQUESTION:
+		varunset(start, str, startp, varflags);
+		/* NOTREACHED */
+	}
+
+	subtype -= VSTRIMRIGHT;
+#ifdef DEBUG
+	if (subtype < 0 || subtype > 3)
+		abort();
+#endif
+
+	rmesc = startp;
+	rmescend = stackblock() + strloc;
+	if (quotes) {
+		rmesc = _rmescapes(startp, RMESCAPE_ALLOC | RMESCAPE_GROW);
+		if (rmesc != startp) {
+			rmescend = expdest;
+			startp = stackblock() + startloc;
+		}
+	}
+	rmescend--;
+	str = stackblock() + strloc;
+	preglob(str, 0);
+
+	/* zero = subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX */
+	zero = subtype >> 1;
+	/* VSTRIMLEFT/VSTRIMRIGHTMAX -> scanleft */
+	scan = (subtype & 1) ^ zero ? scanleft : scanright;
+
+	loc = scan(startp, rmesc, rmescend, str, quotes, zero);
+	if (loc) {
+		if (zero) {
+			memmove(startp, loc, str - loc);
+			loc = startp + (str - loc) - 1;
+		}
+		*loc = '\0';
+	} else
+		loc = str - 1;
+
+out:
+	amount = loc - expdest;
+	STADJUST(amount, expdest);
+
+	/* Remove any recorded regions beyond start of variable */
+	removerecordregions(startloc);
+
+	return p;
+}
+
+
+/*
+ * Expand a variable, and return a pointer to the next character in the
+ * input string.
+ */
+STATIC char *
+evalvar(char *p, int flag)
+{
+	int subtype;
+	int varflags;
+	char *var;
+	int patloc;
+	int startloc;
+	ssize_t varlen;
+	int discard;
+	int quoted;
+
+	varflags = *p++;
+	subtype = varflags & VSTYPE;
+
+	quoted = flag & EXP_QUOTED;
+	var = p;
+	startloc = expdest - (char *)stackblock();
+	p = strchr(p, '=') + 1;
+
+again:
+	varlen = varvalue(var, varflags, flag, quoted);
+	if (varflags & VSNUL)
+		varlen--;
+
+	discard = varlen < 0 ? EXP_DISCARD : 0;
+
+	switch (subtype) {
+	case VSPLUS:
+		discard ^= EXP_DISCARD;
+		/* fall through */
+
+	case 0:
+	case VSMINUS:
+		p = argstr(p, flag | EXP_TILDE | EXP_WORD |
+			      (discard ^ EXP_DISCARD));
+		goto record;
+
+	case VSASSIGN:
+	case VSQUESTION:
+		p = subevalvar(p, var, 0, startloc, varflags,
+			       (flag & ~QUOTES_ESC) |
+			       (discard ^ EXP_DISCARD));
+
+		if ((flag | ~discard) & EXP_DISCARD)
+			goto record;
+
+		varflags &= ~VSNUL;
+		subtype = VSNORMAL;
+		goto again;
+	}
+
+	if ((discard & ~flag) && uflag)
+		varunset(p, var, 0, 0);
+
+	if (subtype == VSLENGTH) {
+		p++;
+		if (flag & EXP_DISCARD)
+			return p;
+		cvtnum(varlen > 0 ? varlen : 0, flag);
+		goto really_record;
+	}
+
+	if (subtype == VSNORMAL)
+		goto record;
+
+#ifdef DEBUG
+	switch (subtype) {
+	case VSTRIMLEFT:
+	case VSTRIMLEFTMAX:
+	case VSTRIMRIGHT:
+	case VSTRIMRIGHTMAX:
+		break;
+	default:
+		abort();
+	}
+#endif
+
+	flag |= discard;
+	if (!(flag & EXP_DISCARD)) {
+		/*
+		 * Terminate the string and start recording the pattern
+		 * right after it
+		 */
+		STPUTC('\0', expdest);
+	}
+
+	patloc = expdest - (char *)stackblock();
+	p = subevalvar(p, NULL, patloc, startloc, varflags, flag);
+
+record:
+	if ((flag | discard) & EXP_DISCARD)
+		return p;
+
+really_record:
+	if (quoted) {
+		quoted = *var == '@' && shellparam.nparam;
+		if (!quoted)
+			return p;
+	}
+	recordregion(startloc, expdest - (char *)stackblock(), quoted);
+	return p;
+}
+
+
+/*
+ * Put a string on the stack.
+ */
+
+static size_t memtodest(const char *p, size_t len, int flags)
+{
+	const char *syntax = flags & EXP_QUOTED ? DQSYNTAX : BASESYNTAX;
+	char *q;
+	char *s;
+
+	if (unlikely(!len))
+		return 0;
+
+	q = makestrspace(len * 2, expdest);
+	s = q;
+
+	do {
+		int c = (signed char)*p++;
+		if (c) {
+			if ((flags & QUOTES_ESC) &&
+			    ((syntax[c] == CCTL) ||
+			     (flags & EXP_QUOTED && syntax[c] == CBACK)))
+				USTPUTC(CTLESC, q);
+		} else if (!(flags & EXP_KEEPNUL))
+			continue;
+		USTPUTC(c, q);
+	} while (--len);
+
+	expdest = q;
+	return q - s;
+}
+
+
+static size_t strtodest(const char *p, int flags)
+{
+	size_t len = strlen(p);
+	memtodest(p, len, flags);
+	return len;
+}
+
+
+
+/*
+ * Add the value of a specialized variable to the stack string.
+ */
+
+STATIC ssize_t
+varvalue(char *name, int varflags, int flags, int quoted)
+{
+	int num;
+	char *p;
+	int i;
+	int sep;
+	char sepc;
+	char **ap;
+	int subtype = varflags & VSTYPE;
+	int discard = (subtype == VSPLUS || subtype == VSLENGTH) |
+		      (flags & EXP_DISCARD);
+	ssize_t len = 0;
+	char c;
+
+	if (!subtype) {
+		if (discard)
+			return -1;
+
+		sh_error("Bad substitution");
+	}
+
+	flags |= EXP_KEEPNUL;
+	flags &= discard ? ~QUOTES_ESC : ~0;
+	sep = (flags & EXP_FULL) << CHAR_BIT;
+
+	switch (*name) {
+	case '$':
+		num = rootpid;
+		goto numvar;
+	case '?':
+		num = exitstatus;
+		goto numvar;
+	case '#':
+		num = shellparam.nparam;
+		goto numvar;
+	case '!':
+		num = backgndpid;
+		if (num == 0)
+			return -1;
+numvar:
+		len = cvtnum(num, flags);
+		break;
+	case '-':
+		p = makestrspace(NOPTS, expdest);
+		for (i = NOPTS - 1; i >= 0; i--) {
+			if (optlist[i] && optletters[i]) {
+				USTPUTC(optletters[i], p);
+				len++;
+			}
+		}
+		expdest = p;
+		break;
+	case '@':
+		if (quoted && sep)
+			goto param;
+		/* fall through */
+	case '*':
+		/* We will set c to 0 or ~0 depending on whether
+		 * we're doing field splitting.  We won't do field
+		 * splitting if either we're quoted or sep is zero.
+		 *
+		 * Instead of testing (quoted || !sep) the following
+		 * trick optimises away any branches by using the
+		 * fact that EXP_QUOTED (which is the only bit that
+		 * can be set in quoted) is the same as EXP_FULL <<
+		 * CHAR_BIT (which is the only bit that can be set
+		 * in sep).
+		 */
+#if EXP_QUOTED >> CHAR_BIT != EXP_FULL
+#error The following two lines expect EXP_QUOTED == EXP_FULL << CHAR_BIT
+#endif
+		c = !((quoted | ~sep) & EXP_QUOTED) - 1;
+		sep &= ~quoted;
+		sep |= ifsset() ? (unsigned char)(c & ifsval()[0]) : ' ';
+param:
+		sepc = sep;
+		if (!(ap = shellparam.p))
+			return -1;
+		while ((p = *ap++)) {
+			len += strtodest(p, flags);
+
+			if (*ap && sep) {
+				len++;
+				memtodest(&sepc, 1, flags);
+			}
+		}
+		break;
+	case '0':
+	case '1':
+	case '2':
+	case '3':
+	case '4':
+	case '5':
+	case '6':
+	case '7':
+	case '8':
+	case '9':
+		num = atoi(name);
+		if (num < 0 || num > shellparam.nparam)
+			return -1;
+		p = num ? shellparam.p[num - 1] : arg0;
+		goto value;
+	default:
+		p = lookupvar(name);
+value:
+		if (!p)
+			return -1;
+
+		len = strtodest(p, flags);
+		break;
+	}
+
+	if (discard)
+		STADJUST(-len, expdest);
+
+	return len;
+}
+
+
+
+/*
+ * Record the fact that we have to scan this region of the
+ * string for IFS characters.
+ */
+
+void
+recordregion(int start, int end, int nulonly)
+{
+	struct ifsregion *ifsp;
+
+	if (ifslastp == NULL) {
+		ifsp = &ifsfirst;
+	} else {
+		INTOFF;
+		ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
+		ifsp->next = NULL;
+		ifslastp->next = ifsp;
+		INTON;
+	}
+	ifslastp = ifsp;
+	ifslastp->begoff = start;
+	ifslastp->endoff = end;
+	ifslastp->nulonly = nulonly;
+}
+
+
+
+/*
+ * Break the argument string into pieces based upon IFS and add the
+ * strings to the argument list.  The regions of the string to be
+ * searched for IFS characters have been stored by recordregion.
+ * If maxargs is non-negative, at most maxargs arguments will be created, by
+ * joining together the last arguments.
+ */
+void
+ifsbreakup(char *string, int maxargs, struct arglist *arglist)
+{
+	struct ifsregion *ifsp;
+	struct strlist *sp;
+	char *start;
+	char *p;
+	char *q;
+	char *r = NULL;
+	const char *ifs, *realifs;
+	int ifsspc;
+	int nulonly;
+
+
+	start = string;
+	if (ifslastp != NULL) {
+		ifsspc = 0;
+		nulonly = 0;
+		realifs = ifsset() ? ifsval() : defifs;
+		ifsp = &ifsfirst;
+		do {
+			int afternul;
+
+			p = string + ifsp->begoff;
+			afternul = nulonly;
+			nulonly = ifsp->nulonly;
+			ifs = nulonly ? nullstr : realifs;
+			ifsspc = 0;
+			while (p < string + ifsp->endoff) {
+				int c;
+				bool isifs;
+				bool isdefifs;
+
+				q = p;
+				c = *p++;
+				if (c == (char)CTLESC)
+					c = *p++;
+
+				isifs = strchr(ifs, c);
+				isdefifs = false;
+				if (isifs)
+					isdefifs = strchr(defifs, c);
+
+				/* If only reading one more argument:
+				 * If we have exactly one field,
+				 * read that field without its terminator.
+				 * If we have more than one field,
+				 * read all fields including their terminators,
+				 * except for trailing IFS whitespace.
+				 *
+				 * This means that if we have only IFS
+				 * characters left, and at most one
+				 * of them is non-whitespace, we stop
+				 * reading here.
+				 * Otherwise, we read all the remaining
+				 * characters except for trailing
+				 * IFS whitespace.
+				 *
+				 * In any case, r indicates the start
+				 * of the characters to remove, or NULL
+				 * if no characters should be removed.
+				 */
+				if (!maxargs) {
+					if (isdefifs) {
+						if (!r)
+							r = q;
+						continue;
+					}
+
+					if (!(isifs && ifsspc))
+						r = NULL;
+
+					ifsspc = 0;
+					continue;
+				}
+
+				if (ifsspc) {
+					if (isifs)
+						q = p;
+
+					start = q;
+
+					if (isdefifs)
+						continue;
+
+					isifs = false;
+				}
+
+				if (isifs) {
+					if (!(afternul || nulonly))
+						ifsspc = isdefifs;
+					/* Ignore IFS whitespace at start */
+					if (q == start && ifsspc) {
+						start = p;
+						ifsspc = 0;
+						continue;
+					}
+					if (maxargs > 0 && !--maxargs) {
+						r = q;
+						continue;
+					}
+					*q = '\0';
+					sp = (struct strlist *)stalloc(sizeof *sp);
+					sp->text = start;
+					*arglist->lastp = sp;
+					arglist->lastp = &sp->next;
+					start = p;
+					continue;
+				}
+
+				ifsspc = 0;
+			}
+		} while ((ifsp = ifsp->next) != NULL);
+		if (nulonly)
+			goto add;
+	}
+
+	if (r)
+		*r = '\0';
+
+	if (!*start)
+		return;
+
+add:
+	sp = (struct strlist *)stalloc(sizeof *sp);
+	sp->text = start;
+	*arglist->lastp = sp;
+	arglist->lastp = &sp->next;
+}
+
+void ifsfree(void)
+{
+	struct ifsregion *p = ifsfirst.next;
+
+	if (!p)
+		goto out;
+
+	INTOFF;
+	do {
+		struct ifsregion *ifsp;
+		ifsp = p->next;
+		ckfree(p);
+		p = ifsp;
+	} while (p);
+	ifsfirst.next = NULL;
+	INTON;
+
+out:
+	ifslastp = NULL;
+}
+
+
+
+/*
+ * Expand shell metacharacters.  At this point, the only control characters
+ * should be escapes.  The results are stored in the list exparg.
+ */
+
+#ifdef HAVE_GLOB
+STATIC void
+expandmeta(struct strlist *str)
+{
+	/* TODO - EXP_REDIR */
+
+	while (str) {
+		const char *p;
+		glob_t pglob;
+		int i;
+
+		if (fflag)
+			goto nometa;
+		INTOFF;
+		p = preglob(str->text, RMESCAPE_ALLOC | RMESCAPE_HEAP);
+		i = glob(p, GLOB_NOMAGIC, 0, &pglob);
+		if (p != str->text)
+			ckfree(p);
+		switch (i) {
+		case 0:
+			if ((pglob.gl_flags & (GLOB_NOMAGIC | GLOB_NOCHECK)) ==
+			    (GLOB_NOMAGIC | GLOB_NOCHECK))
+				goto nometa2;
+			addglob(&pglob);
+			globfree(&pglob);
+			INTON;
+			break;
+		case GLOB_NOMATCH:
+nometa2:
+			globfree(&pglob);
+			INTON;
+nometa:
+			*exparg.lastp = str;
+			rmescapes(str->text);
+			exparg.lastp = &str->next;
+			break;
+		default:	/* GLOB_NOSPACE */
+			sh_error("Out of space");
+		}
+		str = str->next;
+	}
+}
+
+
+/*
+ * Add the result of glob(3) to the list.
+ */
+
+STATIC void
+addglob(pglob)
+	const glob_t *pglob;
+{
+	char **p = pglob->gl_pathv;
+
+	do {
+		addfname(*p);
+	} while (*++p);
+}
+
+
+#else	/* HAVE_GLOB */
+STATIC char *expdir;
+STATIC unsigned expdir_max;
+
+
+STATIC void
+expandmeta(struct strlist *str)
+{
+	static const char metachars[] = {
+		'*', '?', '[', 0
+	};
+	/* TODO - EXP_REDIR */
+
+	while (str) {
+		struct strlist **savelastp;
+		struct strlist *sp;
+		char *p;
+		unsigned len;
+
+		if (fflag)
+			goto nometa;
+		if (!strpbrk(str->text, metachars))
+			goto nometa;
+		savelastp = exparg.lastp;
+
+		INTOFF;
+		p = preglob(str->text, RMESCAPE_ALLOC | RMESCAPE_HEAP);
+		len = strlen(p);
+		expdir_max = len + PATH_MAX;
+		expdir = ckmalloc(expdir_max);
+
+		expmeta(p, len, 0);
+		ckfree(expdir);
+		if (p != str->text)
+			ckfree(p);
+		INTON;
+		if (exparg.lastp == savelastp) {
+			/*
+			 * no matches
+			 */
+nometa:
+			*exparg.lastp = str;
+			rmescapes(str->text);
+			exparg.lastp = &str->next;
+		} else {
+			*exparg.lastp = NULL;
+			*savelastp = sp = expsort(*savelastp);
+			while (sp->next != NULL)
+				sp = sp->next;
+			exparg.lastp = &sp->next;
+		}
+		str = str->next;
+	}
+}
+
+
+/*
+ * Do metacharacter (i.e. *, ?, [...]) expansion.
+ */
+
+STATIC void
+expmeta(char *name, unsigned name_len, unsigned expdir_len)
+{
+	char *enddir = expdir + expdir_len;
+	char *p;
+	const char *cp;
+	char *start;
+	char *endname;
+	int metaflag;
+	struct stat64 statb;
+	DIR *dirp;
+	struct dirent64 *dp;
+	int atend;
+	int matchdot;
+	int esc;
+
+	metaflag = 0;
+	start = name;
+	for (p = name; esc = 0, *p; p += esc + 1) {
+		if (*p == '*' || *p == '?')
+			metaflag = 1;
+		else if (*p == '[') {
+			char *q = p + 1;
+			if (*q == '!')
+				q++;
+			for (;;) {
+				if (*q == '\\')
+					q++;
+				if (*q == '/' || *q == '\0')
+					break;
+				if (*++q == ']') {
+					metaflag = 1;
+					break;
+				}
+			}
+		} else {
+			if (*p == '\\' && p[1])
+				esc++;
+			if (p[esc] == '/') {
+				if (metaflag)
+					break;
+				start = p + esc + 1;
+			}
+		}
+	}
+	if (metaflag == 0) {	/* we've reached the end of the file name */
+		if (!expdir_len)
+			return;
+		p = name;
+		do {
+			if (*p == '\\' && p[1])
+				p++;
+			*enddir++ = *p;
+		} while (*p++);
+		if (lstat64(expdir, &statb) >= 0)
+			addfname(expdir);
+		return;
+	}
+	endname = p;
+	if (name < start) {
+		p = name;
+		do {
+			if (*p == '\\' && p[1])
+				p++;
+			*enddir++ = *p++;
+		} while (p < start);
+	}
+	*enddir = 0;
+	cp = expdir;
+	expdir_len = enddir - cp;
+	if (!expdir_len)
+		cp = ".";
+	if ((dirp = opendir(cp)) == NULL)
+		return;
+	if (*endname == 0) {
+		atend = 1;
+	} else {
+		atend = 0;
+		*endname = '\0';
+		endname += esc + 1;
+	}
+	name_len -= endname - name;
+	matchdot = 0;
+	p = start;
+	if (*p == '\\')
+		p++;
+	if (*p == '.')
+		matchdot++;
+	while (! int_pending() && (dp = readdir64(dirp)) != NULL) {
+		if (dp->d_name[0] == '.' && ! matchdot)
+			continue;
+		if (pmatch(start, dp->d_name)) {
+			if (atend) {
+				scopy(dp->d_name, enddir);
+				addfname(expdir);
+			} else {
+				unsigned offset;
+				unsigned len;
+
+				p = stpcpy(enddir, dp->d_name);
+				*p = '/';
+
+				offset = p - expdir + 1;
+				len = offset + name_len + NAME_MAX;
+				if (len > expdir_max) {
+					len += PATH_MAX;
+					expdir = ckrealloc(expdir, len);
+					expdir_max = len;
+				}
+
+				expmeta(endname, name_len, offset);
+				enddir = expdir + expdir_len;
+			}
+		}
+	}
+	closedir(dirp);
+	if (! atend)
+		endname[-esc - 1] = esc ? '\\' : '/';
+}
+#endif	/* HAVE_GLOB */
+
+
+/*
+ * Add a file name to the list.
+ */
+
+STATIC void
+addfname(char *name)
+{
+	struct strlist *sp;
+
+	sp = (struct strlist *)stalloc(sizeof *sp);
+	sp->text = sstrdup(name);
+	*exparg.lastp = sp;
+	exparg.lastp = &sp->next;
+}
+
+
+#ifndef HAVE_GLOB
+/*
+ * Sort the results of file name expansion.  It calculates the number of
+ * strings to sort and then calls msort (short for merge sort) to do the
+ * work.
+ */
+
+STATIC struct strlist *
+expsort(struct strlist *str)
+{
+	int len;
+	struct strlist *sp;
+
+	len = 0;
+	for (sp = str ; sp ; sp = sp->next)
+		len++;
+	return msort(str, len);
+}
+
+
+STATIC struct strlist *
+msort(struct strlist *list, int len)
+{
+	struct strlist *p, *q = NULL;
+	struct strlist **lpp;
+	int half;
+	int n;
+
+	if (len <= 1)
+		return list;
+	half = len >> 1;
+	p = list;
+	for (n = half ; --n >= 0 ; ) {
+		q = p;
+		p = p->next;
+	}
+	q->next = NULL;			/* terminate first half of list */
+	q = msort(list, half);		/* sort first half of list */
+	p = msort(p, len - half);		/* sort second half */
+	lpp = &list;
+	for (;;) {
+		if (strcmp(p->text, q->text) < 0) {
+			*lpp = p;
+			lpp = &p->next;
+			if ((p = *lpp) == NULL) {
+				*lpp = q;
+				break;
+			}
+		} else {
+			*lpp = q;
+			lpp = &q->next;
+			if ((q = *lpp) == NULL) {
+				*lpp = p;
+				break;
+			}
+		}
+	}
+	return list;
+}
+#endif
+
+
+/*
+ * Returns true if the pattern matches the string.
+ */
+
+STATIC inline int
+patmatch(char *pattern, const char *string)
+{
+	return pmatch(preglob(pattern, 0), string);
+}
+
+
+#ifndef HAVE_FNMATCH
+STATIC int ccmatch(const char *p, int chr, const char **r)
+{
+	static const struct class {
+		char name[10];
+		int (*fn)(int);
+	} classes[] = {
+		{ .name = ":alnum:]", .fn = isalnum },
+		{ .name = ":cntrl:]", .fn = iscntrl },
+		{ .name = ":lower:]", .fn = islower },
+		{ .name = ":space:]", .fn = isspace },
+		{ .name = ":alpha:]", .fn = isalpha },
+		{ .name = ":digit:]", .fn = isdigit },
+		{ .name = ":print:]", .fn = isprint },
+		{ .name = ":upper:]", .fn = isupper },
+		{ .name = ":blank:]", .fn = isblank },
+		{ .name = ":graph:]", .fn = isgraph },
+		{ .name = ":punct:]", .fn = ispunct },
+		{ .name = ":xdigit:]", .fn = isxdigit },
+	};
+	const struct class *class, *end;
+
+	end = classes + sizeof(classes) / sizeof(classes[0]);
+	for (class = classes; class < end; class++) {
+		const char *q;
+
+		q = prefix(p, class->name);
+		if (!q)
+			continue;
+		*r = q;
+		return class->fn(chr);
+	}
+
+	*r = 0;
+	return 0;
+}
+
+STATIC int
+pmatch(const char *pattern, const char *string)
+{
+	const char *p, *q;
+	char c;
+
+	p = pattern;
+	q = string;
+	for (;;) {
+		switch (c = *p++) {
+		case '\0':
+			goto breakloop;
+		case '\\':
+			if (*p) {
+				c = *p++;
+			}
+			goto dft;
+		case '?':
+			if (*q++ == '\0')
+				return 0;
+			break;
+		case '*':
+			c = *p;
+			while (c == '*')
+				c = *++p;
+			if (c != '\\' && c != '?' && c != '*' && c != '[') {
+				while (*q != c) {
+					if (*q == '\0')
+						return 0;
+					q++;
+				}
+			}
+			do {
+				if (pmatch(p, q))
+					return 1;
+			} while (*q++ != '\0');
+			return 0;
+		case '[': {
+			const char *startp;
+			int invert, found;
+			char chr;
+
+			startp = p;
+			invert = 0;
+			if (*p == '!') {
+				invert++;
+				p++;
+			}
+			found = 0;
+			chr = *q;
+			if (chr == '\0')
+				return 0;
+			c = *p++;
+			do {
+				if (!c) {
+					p = startp;
+					c = '[';
+					goto dft;
+				}
+				if (c == '[') {
+					const char *r;
+
+					found |= !!ccmatch(p, chr, &r);
+					if (r) {
+						p = r;
+						continue;
+					}
+				} else if (c == '\\')
+					c = *p++;
+				if (*p == '-' && p[1] != ']') {
+					p++;
+					if (*p == '\\')
+						p++;
+					if (chr >= c && chr <= *p)
+						found = 1;
+					p++;
+				} else {
+					if (chr == c)
+						found = 1;
+				}
+			} while ((c = *p++) != ']');
+			if (found == invert)
+				return 0;
+			q++;
+			break;
+		}
+dft:	        default:
+			if (*q++ != c)
+				return 0;
+			break;
+		}
+	}
+breakloop:
+	if (*q != '\0')
+		return 0;
+	return 1;
+}
+#endif
+
+
+
+/*
+ * Remove any CTLESC characters from a string.
+ */
+
+char *
+_rmescapes(char *str, int flag)
+{
+	char *p, *q, *r;
+	int notescaped;
+	int globbing;
+
+	p = strpbrk(str, qchars);
+	if (!p) {
+		return str;
+	}
+	q = p;
+	r = str;
+	if (flag & RMESCAPE_ALLOC) {
+		size_t len = p - str;
+		size_t fulllen = len + strlen(p) + 1;
+
+		if (flag & RMESCAPE_GROW) {
+			int strloc = str - (char *)stackblock();
+
+			r = makestrspace(fulllen, expdest);
+			str = (char *)stackblock() + strloc;
+			p = str + len;
+		} else if (flag & RMESCAPE_HEAP) {
+			r = ckmalloc(fulllen);
+		} else {
+			r = stalloc(fulllen);
+		}
+		q = r;
+		if (len > 0) {
+			q = mempcpy(q, str, len);
+		}
+	}
+	globbing = flag & RMESCAPE_GLOB;
+	notescaped = globbing;
+	while (*p) {
+		if (*p == (char)CTLQUOTEMARK) {
+			p++;
+			notescaped = globbing;
+			continue;
+		}
+		if (*p == '\\') {
+			/* naked back slash */
+			notescaped = 0;
+			goto copy;
+		}
+		if (*p == (char)CTLESC) {
+			p++;
+			if (notescaped)
+				*q++ = '\\';
+		}
+		notescaped = globbing;
+copy:
+		*q++ = *p++;
+	}
+	*q = '\0';
+	if (flag & RMESCAPE_GROW) {
+		expdest = r;
+		STADJUST(q - r + 1, expdest);
+	}
+	return r;
+}
+
+
+
+/*
+ * See if a pattern matches in a case statement.
+ */
+
+int
+casematch(union node *pattern, char *val)
+{
+	struct stackmark smark;
+	int result;
+
+	setstackmark(&smark);
+	argbackq = pattern->narg.backquote;
+	STARTSTACKSTR(expdest);
+	argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
+	ifsfree();
+	result = patmatch(stackblock(), val);
+	popstackmark(&smark);
+	return result;
+}
+
+/*
+ * Our own itoa().
+ */
+
+static size_t cvtnum(intmax_t num, int flags)
+{
+	int len = max_int_length(sizeof(num));
+	char buf[len];
+
+	len = fmtstr(buf, len, "%" PRIdMAX, num);
+	return memtodest(buf, len, flags);
+}
+
+STATIC void
+varunset(const char *end, const char *var, const char *umsg, int varflags)
+{
+	const char *msg;
+	const char *tail;
+
+	tail = nullstr;
+	msg = "parameter not set";
+	if (umsg) {
+		if (*end == (char)CTLENDVAR) {
+			if (varflags & VSNUL)
+				tail = " or null";
+		} else
+			msg = umsg;
+	}
+	sh_error("%.*s: %s%s", end - var - 1, var, msg, tail);
+}
+
+#ifdef mkinit
+
+INCLUDE "expand.h"
+
+EXITRESET {
+	ifsfree();
+}
+
+#endif
diff --git a/src/expand.h b/src/expand.h
new file mode 100644
index 00000000..c44b8481
--- /dev/null
+++ b/src/expand.h
@@ -0,0 +1,83 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)expand.h	8.2 (Berkeley) 5/4/95
+ */
+
+#include <inttypes.h>
+
+struct strlist {
+	struct strlist *next;
+	char *text;
+};
+
+
+struct arglist {
+	struct strlist *list;
+	struct strlist **lastp;
+};
+
+/*
+ * expandarg() flags
+ */
+#define EXP_FULL	0x1	/* perform word splitting & file globbing */
+#define EXP_TILDE	0x2	/* do normal tilde expansion */
+#define	EXP_VARTILDE	0x4	/* expand tildes in an assignment */
+#define	EXP_REDIR	0x8	/* file glob for a redirection (1 match only) */
+#define EXP_CASE	0x10	/* keeps quotes around for CASE pattern */
+#define EXP_VARTILDE2	0x40	/* expand tildes after colons only */
+#define EXP_WORD	0x80	/* expand word in parameter expansion */
+#define EXP_QUOTED	0x100	/* expand word in double quotes */
+#define EXP_KEEPNUL	0x200	/* do not skip NUL characters */
+#define EXP_DISCARD	0x400	/* discard result of expansion */
+
+
+union node;
+void expandarg(union node *, struct arglist *, int);
+#define rmescapes(p) _rmescapes((p), 0)
+char *_rmescapes(char *, int);
+int casematch(union node *, char *);
+void recordregion(int, int, int);
+void removerecordregions(int); 
+void ifsbreakup(char *, int, struct arglist *);
+void ifsfree(void);
+
+/* From arith.y */
+intmax_t arith(const char *);
+int expcmd(int , char **);
+#ifdef USE_LEX
+void arith_lex_reset(void);
+#else
+#define arith_lex_reset()
+#endif
+int yylex(void);
diff --git a/src/funcs/cmv b/src/funcs/cmv
new file mode 100644
index 00000000..91a67c53
--- /dev/null
+++ b/src/funcs/cmv
@@ -0,0 +1,47 @@
+# Copyright (c) 1991, 1993
+#	The Regents of the University of California.  All rights reserved.
+# Copyright (c) 1997-2005
+#	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+#
+# This code is derived from software contributed to Berkeley by
+# Kenneth Almquist.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+#	@(#)cmv	8.2 (Berkeley) 5/4/95
+
+# Conditional move--don't replace an existing file.
+
+cmv() {
+	if test $# != 2
+	then	echo "cmv: arg count"
+		return 2
+	fi
+	if test -f "$2" -o -w "$2"
+	then	echo "$2 exists"
+		return 2
+	fi
+	/bin/mv "$1" "$2"
+}
diff --git a/src/funcs/dirs b/src/funcs/dirs
new file mode 100644
index 00000000..5f6ce635
--- /dev/null
+++ b/src/funcs/dirs
@@ -0,0 +1,71 @@
+# Copyright (c) 1991, 1993
+#	The Regents of the University of California.  All rights reserved.
+# Copyright (c) 1997-2005
+#	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+#
+# This code is derived from software contributed to Berkeley by
+# Kenneth Almquist.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+#	@(#)dirs	8.2 (Berkeley) 5/4/95
+
+# pushd, popd, and dirs --- written by Chris Bertin
+# Pixel Computer Inc. ...!wjh12!pixel!pixutl!chris
+# as modified by Patrick Elam of GTRI and Kenneth Almquist at UW
+
+pushd () {
+	SAVE=`pwd`
+	if [ "$1" = "" ] 
+	then	if [ "$DSTACK" = "" ]
+		then	echo "pushd: directory stack empty."
+			return 1
+		fi
+		set $DSTACK
+		cd $1 || return
+		shift 1
+		DSTACK="$*"
+	else	cd $1 > /dev/null || return
+	fi
+	DSTACK="$SAVE $DSTACK"
+	dirs
+}
+
+popd () {
+	if [ "$DSTACK" = "" ] 
+	then	echo "popd: directory stack empty."
+		return 1
+	fi
+	set $DSTACK
+	cd $1
+	shift
+	DSTACK=$*
+	dirs
+}
+
+dirs () {
+	echo "`pwd` $DSTACK"
+	return 0
+}
diff --git a/src/funcs/kill b/src/funcs/kill
new file mode 100644
index 00000000..c5df95f5
--- /dev/null
+++ b/src/funcs/kill
@@ -0,0 +1,47 @@
+# Copyright (c) 1991, 1993
+#	The Regents of the University of California.  All rights reserved.
+# Copyright (c) 1997-2005
+#	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+#
+# This code is derived from software contributed to Berkeley by
+# Kenneth Almquist.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+#	@(#)kill	8.2 (Berkeley) 5/4/95
+
+# Convert job names to process ids and then run /bin/kill.
+
+kill() {
+	local args x
+	args=
+	for x in "$@"
+	do	case $x in
+		%*)	x=`jobid "$x"` ;;
+		esac
+		args="$args $x"
+	done
+	/bin/kill $args
+}
diff --git a/src/funcs/login b/src/funcs/login
new file mode 100644
index 00000000..215e5352
--- /dev/null
+++ b/src/funcs/login
@@ -0,0 +1,36 @@
+# Copyright (c) 1991, 1993
+#	The Regents of the University of California.  All rights reserved.
+# Copyright (c) 1997-2005
+#	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+#
+# This code is derived from software contributed to Berkeley by
+# Kenneth Almquist.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+#	@(#)login	8.2 (Berkeley) 5/4/95
+
+# replaces the login builtin in the BSD shell
+login () exec login "$@"
diff --git a/src/funcs/newgrp b/src/funcs/newgrp
new file mode 100644
index 00000000..ec0e7e5a
--- /dev/null
+++ b/src/funcs/newgrp
@@ -0,0 +1,35 @@
+# Copyright (c) 1991, 1993
+#	The Regents of the University of California.  All rights reserved.
+# Copyright (c) 1997-2005
+#	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+#
+# This code is derived from software contributed to Berkeley by
+# Kenneth Almquist.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+#	@(#)newgrp	8.2 (Berkeley) 5/4/95
+
+newgrp() exec newgrp "$@"
diff --git a/src/funcs/popd b/src/funcs/popd
new file mode 100644
index 00000000..7bccf50d
--- /dev/null
+++ b/src/funcs/popd
@@ -0,0 +1,71 @@
+# Copyright (c) 1991, 1993
+#	The Regents of the University of California.  All rights reserved.
+# Copyright (c) 1997-2005
+#	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+#
+# This code is derived from software contributed to Berkeley by
+# Kenneth Almquist.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+#	@(#)popd	8.2 (Berkeley) 5/4/95
+
+# pushd, popd, and dirs --- written by Chris Bertin
+# Pixel Computer Inc. ...!wjh12!pixel!pixutl!chris
+# as modified by Patrick Elam of GTRI and Kenneth Almquist at UW
+
+pushd () {
+	SAVE=`pwd`
+	if [ "$1" = "" ] 
+	then	if [ "$DSTACK" = "" ]
+		then	echo "pushd: directory stack empty."
+			return 1
+		fi
+		set $DSTACK
+		cd $1 || return
+		shift 1
+		DSTACK="$*"
+	else	cd $1 > /dev/null || return
+	fi
+	DSTACK="$SAVE $DSTACK"
+	dirs
+}
+
+popd () {
+	if [ "$DSTACK" = "" ] 
+	then	echo "popd: directory stack empty."
+		return 1
+	fi
+	set $DSTACK
+	cd $1
+	shift
+	DSTACK=$*
+	dirs
+}
+
+dirs () {
+	echo "`pwd` $DSTACK"
+	return 0
+}
diff --git a/src/funcs/pushd b/src/funcs/pushd
new file mode 100644
index 00000000..19ac8e08
--- /dev/null
+++ b/src/funcs/pushd
@@ -0,0 +1,71 @@
+# Copyright (c) 1991, 1993
+#	The Regents of the University of California.  All rights reserved.
+# Copyright (c) 1997-2005
+#	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+#
+# This code is derived from software contributed to Berkeley by
+# Kenneth Almquist.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+#	@(#)pushd	8.2 (Berkeley) 5/4/95
+
+# pushd, popd, and dirs --- written by Chris Bertin
+# Pixel Computer Inc. ...!wjh12!pixel!pixutl!chris
+# as modified by Patrick Elam of GTRI and Kenneth Almquist at UW
+
+pushd () {
+	SAVE=`pwd`
+	if [ "$1" = "" ] 
+	then	if [ "$DSTACK" = "" ]
+		then	echo "pushd: directory stack empty."
+			return 1
+		fi
+		set $DSTACK
+		cd $1 || return
+		shift 1
+		DSTACK="$*"
+	else	cd $1 > /dev/null || return
+	fi
+	DSTACK="$SAVE $DSTACK"
+	dirs
+}
+
+popd () {
+	if [ "$DSTACK" = "" ] 
+	then	echo "popd: directory stack empty."
+		return 1
+	fi
+	set $DSTACK
+	cd $1
+	shift
+	DSTACK=$*
+	dirs
+}
+
+dirs () {
+	echo "`pwd` $DSTACK"
+	return 0
+}
diff --git a/src/funcs/suspend b/src/funcs/suspend
new file mode 100644
index 00000000..44844678
--- /dev/null
+++ b/src/funcs/suspend
@@ -0,0 +1,39 @@
+# Copyright (c) 1991, 1993
+#	The Regents of the University of California.  All rights reserved.
+# Copyright (c) 1997-2005
+#	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+#
+# This code is derived from software contributed to Berkeley by
+# Kenneth Almquist.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+#	@(#)suspend	8.2 (Berkeley) 5/4/95
+
+suspend() {
+	local -
+	set +j
+	kill -TSTP 0
+}
diff --git a/src/histedit.c b/src/histedit.c
new file mode 100644
index 00000000..f5c90aba
--- /dev/null
+++ b/src/histedit.c
@@ -0,0 +1,494 @@
+/*-
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/param.h>
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <getopt.h>
+/*
+ * Editline and history functions (and glue).
+ */
+#include "shell.h"
+#include "parser.h"
+#include "var.h"
+#include "options.h"
+#include "main.h"
+#include "output.h"
+#include "mystring.h"
+#include "error.h"
+#ifndef SMALL
+#include "myhistedit.h"
+#include "eval.h"
+#include "memalloc.h"
+
+#define MAXHISTLOOPS	4	/* max recursions through fc */
+#define DEFEDITOR	"ed"	/* default editor *should* be $EDITOR */
+
+History *hist;	/* history cookie */
+EditLine *el;	/* editline cookie */
+int displayhist;
+static FILE *el_in, *el_out;
+
+STATIC const char *fc_replace(const char *, char *, char *);
+
+#ifdef DEBUG
+extern FILE *tracefile;
+#endif
+
+/*
+ * Set history and editing status.  Called whenever the status may
+ * have changed (figures out what to do).
+ */
+void
+histedit(void)
+{
+	FILE *el_err;
+
+#define editing (Eflag || Vflag)
+
+	if (iflag) {
+		if (!hist) {
+			/*
+			 * turn history on
+			 */
+			INTOFF;
+			hist = history_init();
+			INTON;
+
+			if (hist != NULL)
+				sethistsize(histsizeval());
+			else
+				out2str("sh: can't initialize history\n");
+		}
+		if (editing && !el && isatty(0)) { /* && isatty(2) ??? */
+			/*
+			 * turn editing on
+			 */
+			INTOFF;
+			if (el_in == NULL)
+				el_in = fdopen(0, "r");
+			if (el_out == NULL)
+				el_out = fdopen(2, "w");
+			if (el_in == NULL || el_out == NULL)
+				goto bad;
+			el_err = el_out;
+#if DEBUG
+			if (tracefile)
+				el_err = tracefile;
+#endif
+			el = el_init(arg0, el_in, el_out, el_err);
+			if (el != NULL) {
+				if (hist)
+					el_set(el, EL_HIST, history, hist);
+				el_set(el, EL_PROMPT, getprompt);
+			} else {
+bad:
+				out2str("sh: can't initialize editing\n");
+			}
+			INTON;
+		} else if (!editing && el) {
+			INTOFF;
+			el_end(el);
+			el = NULL;
+			INTON;
+		}
+		if (el) {
+			if (Vflag)
+				el_set(el, EL_EDITOR, "vi");
+			else if (Eflag)
+				el_set(el, EL_EDITOR, "emacs");
+			el_source(el, NULL);
+		}
+	} else {
+		INTOFF;
+		if (el) {	/* no editing if not interactive */
+			el_end(el);
+			el = NULL;
+		}
+		if (hist) {
+			history_end(hist);
+			hist = NULL;
+		}
+		INTON;
+	}
+}
+
+
+void
+sethistsize(const char *hs)
+{
+	int histsize;
+	HistEvent he;
+
+	if (hist != NULL) {
+		if (hs == NULL || *hs == '\0' ||
+		   (histsize = atoi(hs)) < 0)
+			histsize = 100;
+		history(hist, &he, H_SETSIZE, histsize);
+	}
+}
+
+void
+setterm(const char *term)
+{
+	if (el != NULL && term != NULL)
+		if (el_set(el, EL_TERMINAL, term) != 0) {
+			outfmt(out2, "sh: Can't set terminal type %s\n", term);
+			outfmt(out2, "sh: Using dumb terminal settings.\n");
+		}
+}
+
+/*
+ *  This command is provided since POSIX decided to standardize
+ *  the Korn shell fc command.  Oh well...
+ */
+int
+histcmd(int argc, char **argv)
+{
+	int ch;
+	const char *editor = NULL;
+	HistEvent he;
+	int lflg = 0, nflg = 0, rflg = 0, sflg = 0;
+	int i, retval;
+	const char *firststr, *laststr;
+	int first, last, direction;
+	char *pat = NULL, *repl;	/* ksh "fc old=new" crap */
+	static int active = 0;
+	struct jmploc jmploc;
+	struct jmploc *volatile savehandler;
+	char editfile[MAXPATHLEN + 1];
+	FILE *efp;
+#ifdef __GNUC__
+	/* Avoid longjmp clobbering */
+	(void) &editor;
+	(void) &lflg;
+	(void) &nflg;
+	(void) &rflg;
+	(void) &sflg;
+	(void) &firststr;
+	(void) &laststr;
+	(void) &pat;
+	(void) &repl;
+	(void) &efp;
+	(void) &argc;
+	(void) &argv;
+#endif
+
+	if (hist == NULL)
+		sh_error("history not active");
+
+	if (argc == 1)
+		sh_error("missing history argument");
+
+#ifdef __GLIBC__
+	optind = 0;
+#else
+	optreset = 1; optind = 1; /* initialize getopt */
+#endif
+	while (not_fcnumber(argv[optind]) &&
+	      (ch = getopt(argc, argv, ":e:lnrs")) != -1)
+		switch ((char)ch) {
+		case 'e':
+			editor = optionarg;
+			break;
+		case 'l':
+			lflg = 1;
+			break;
+		case 'n':
+			nflg = 1;
+			break;
+		case 'r':
+			rflg = 1;
+			break;
+		case 's':
+			sflg = 1;
+			break;
+		case ':':
+			sh_error("option -%c expects argument", optopt);
+			/* NOTREACHED */
+		case '?':
+		default:
+			sh_error("unknown option: -%c", optopt);
+			/* NOTREACHED */
+		}
+	argc -= optind, argv += optind;
+
+	/*
+	 * If executing...
+	 */
+	if (lflg == 0 || editor || sflg) {
+		lflg = 0;	/* ignore */
+		editfile[0] = '\0';
+		/*
+		 * Catch interrupts to reset active counter and
+		 * cleanup temp files.
+		 */
+		if (setjmp(jmploc.loc)) {
+			active = 0;
+			if (*editfile)
+				unlink(editfile);
+			handler = savehandler;
+			longjmp(handler->loc, 1);
+		}
+		savehandler = handler;
+		handler = &jmploc;
+		if (++active > MAXHISTLOOPS) {
+			active = 0;
+			displayhist = 0;
+			sh_error("called recursively too many times");
+		}
+		/*
+		 * Set editor.
+		 */
+		if (sflg == 0) {
+			if (editor == NULL &&
+			    (editor = bltinlookup("FCEDIT")) == NULL &&
+			    (editor = bltinlookup("EDITOR")) == NULL)
+				editor = DEFEDITOR;
+			if (editor[0] == '-' && editor[1] == '\0') {
+				sflg = 1;	/* no edit */
+				editor = NULL;
+			}
+		}
+	}
+
+	/*
+	 * If executing, parse [old=new] now
+	 */
+	if (lflg == 0 && argc > 0 &&
+	     ((repl = strchr(argv[0], '=')) != NULL)) {
+		pat = argv[0];
+		*repl++ = '\0';
+		argc--, argv++;
+	}
+	/*
+	 * determine [first] and [last]
+	 */
+	switch (argc) {
+	case 0:
+		firststr = lflg ? "-16" : "-1";
+		laststr = "-1";
+		break;
+	case 1:
+		firststr = argv[0];
+		laststr = lflg ? "-1" : argv[0];
+		break;
+	case 2:
+		firststr = argv[0];
+		laststr = argv[1];
+		break;
+	default:
+		sh_error("too many args");
+		/* NOTREACHED */
+	}
+	/*
+	 * Turn into event numbers.
+	 */
+	first = str_to_event(firststr, 0);
+	last = str_to_event(laststr, 1);
+
+	if (rflg) {
+		i = last;
+		last = first;
+		first = i;
+	}
+	/*
+	 * XXX - this should not depend on the event numbers
+	 * always increasing.  Add sequence numbers or offset
+	 * to the history element in next (diskbased) release.
+	 */
+	direction = first < last ? H_PREV : H_NEXT;
+
+	/*
+	 * If editing, grab a temp file.
+	 */
+	if (editor) {
+		int fd;
+		INTOFF;		/* easier */
+		sprintf(editfile, "%s_shXXXXXX", _PATH_TMP);
+		if ((fd = mkstemp(editfile)) < 0)
+			sh_error("can't create temporary file %s", editfile);
+		if ((efp = fdopen(fd, "w")) == NULL) {
+			close(fd);
+			sh_error("can't allocate stdio buffer for temp");
+		}
+	}
+
+	/*
+	 * Loop through selected history events.  If listing or executing,
+	 * do it now.  Otherwise, put into temp file and call the editor
+	 * after.
+	 *
+	 * The history interface needs rethinking, as the following
+	 * convolutions will demonstrate.
+	 */
+	history(hist, &he, H_FIRST);
+	retval = history(hist, &he, H_NEXT_EVENT, first);
+	for (;retval != -1; retval = history(hist, &he, direction)) {
+		if (lflg) {
+			if (!nflg)
+				out1fmt("%5d ", he.num);
+			out1str(he.str);
+		} else {
+			const char *s = pat ?
+			   fc_replace(he.str, pat, repl) : he.str;
+
+			if (sflg) {
+				if (displayhist) {
+					out2str(s);
+				}
+
+				evalstring(s, 0);
+				if (displayhist && hist) {
+					/*
+					 *  XXX what about recursive and
+					 *  relative histnums.
+					 */
+					history(hist, &he, H_ENTER, s);
+				}
+			} else
+				fputs(s, efp);
+		}
+		/*
+		 * At end?  (if we were to lose last, we'd sure be
+		 * messed up).
+		 */
+		if (he.num == last)
+			break;
+	}
+	if (editor) {
+		char *editcmd;
+
+		fclose(efp);
+		editcmd = stalloc(strlen(editor) + strlen(editfile) + 2);
+		sprintf(editcmd, "%s %s", editor, editfile);
+		/* XXX - should use no JC command */
+		evalstring(editcmd, 0);
+		INTON;
+		readcmdfile(editfile);	/* XXX - should read back - quick tst */
+		unlink(editfile);
+	}
+
+	if (lflg == 0 && active > 0)
+		--active;
+	if (displayhist)
+		displayhist = 0;
+	return 0;
+}
+
+STATIC const char *
+fc_replace(const char *s, char *p, char *r)
+{
+	char *dest;
+	int plen = strlen(p);
+
+	STARTSTACKSTR(dest);
+	while (*s) {
+		if (*s == *p && strncmp(s, p, plen) == 0) {
+			while (*r)
+				STPUTC(*r++, dest);
+			s += plen;
+			*p = '\0';	/* so no more matches */
+		} else
+			STPUTC(*s++, dest);
+	}
+	STACKSTRNUL(dest);
+	dest = grabstackstr(dest);
+
+	return (dest);
+}
+
+int
+not_fcnumber(char *s)
+{
+	if (s == NULL)
+		return 0;
+        if (*s == '-')
+                s++;
+	return (!is_number(s));
+}
+
+int
+str_to_event(const char *str, int last)
+{
+	HistEvent he;
+	const char *s = str;
+	int relative = 0;
+	int i, retval;
+
+	retval = history(hist, &he, H_FIRST);
+	switch (*s) {
+	case '-':
+		relative = 1;
+		/*FALLTHROUGH*/
+	case '+':
+		s++;
+	}
+	if (is_number(s)) {
+		i = atoi(s);
+		if (relative) {
+			while (retval != -1 && i--) {
+				retval = history(hist, &he, H_NEXT);
+			}
+			if (retval == -1)
+				retval = history(hist, &he, H_LAST);
+		} else {
+			retval = history(hist, &he, H_NEXT_EVENT, i);
+			if (retval == -1) {
+				/*
+				 * the notion of first and last is
+				 * backwards to that of the history package
+				 */
+				retval = history(hist, &he,
+						last ? H_FIRST : H_LAST);
+			}
+		}
+		if (retval == -1)
+			sh_error("history number %s not found (internal error)",
+				 str);
+	} else {
+		/*
+		 * pattern
+		 */
+		retval = history(hist, &he, H_PREV_STR, str);
+		if (retval == -1)
+			sh_error("history pattern not found: %s", str);
+	}
+	return (he.num);
+}
+#endif
diff --git a/src/init.h b/src/init.h
new file mode 100644
index 00000000..d56fb28e
--- /dev/null
+++ b/src/init.h
@@ -0,0 +1,40 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)init.h	8.2 (Berkeley) 5/4/95
+ */
+
+void init(void);
+void exitreset(void);
+void forkreset(void);
+void reset(void);
diff --git a/src/input.c b/src/input.c
new file mode 100644
index 00000000..17544e78
--- /dev/null
+++ b/src/input.c
@@ -0,0 +1,502 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdio.h>	/* defines BUFSIZ */
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+/*
+ * This file implements the input routines used by the parser.
+ */
+
+#include "eval.h"
+#include "shell.h"
+#include "redir.h"
+#include "syntax.h"
+#include "input.h"
+#include "output.h"
+#include "options.h"
+#include "memalloc.h"
+#include "error.h"
+#include "alias.h"
+#include "parser.h"
+#include "main.h"
+#ifndef SMALL
+#include "myhistedit.h"
+#endif
+
+#define EOF_NLEFT -99		/* value of parsenleft when EOF pushed back */
+#define IBUFSIZ (BUFSIZ + 1)
+
+
+MKINIT struct parsefile basepf;	/* top level input file */
+MKINIT char basebuf[IBUFSIZ];	/* buffer for top level input file */
+struct parsefile *parsefile = &basepf;	/* current input file */
+int whichprompt;		/* 1 == PS1, 2 == PS2 */
+
+STATIC void pushfile(void);
+static int preadfd(void);
+static void setinputfd(int fd, int push);
+static int preadbuffer(void);
+
+#ifdef mkinit
+INCLUDE <stdio.h>
+INCLUDE <unistd.h>
+INCLUDE "input.h"
+INCLUDE "error.h"
+
+INIT {
+	basepf.nextc = basepf.buf = basebuf;
+	basepf.linno = 1;
+}
+
+RESET {
+	/* clear input buffer */
+	basepf.lleft = basepf.nleft = 0;
+	popallfiles();
+}
+
+FORKRESET {
+	popallfiles();
+	if (parsefile->fd > 0) {
+		close(parsefile->fd);
+		parsefile->fd = 0;
+	}
+}
+#endif
+
+
+/*
+ * Read a character from the script, returning PEOF on end of file.
+ * Nul characters in the input are silently discarded.
+ */
+
+int
+pgetc(void)
+{
+	int c;
+
+	if (parsefile->unget)
+		return parsefile->lastc[--parsefile->unget];
+
+	if (--parsefile->nleft >= 0)
+		c = (signed char)*parsefile->nextc++;
+	else
+		c = preadbuffer();
+
+	parsefile->lastc[1] = parsefile->lastc[0];
+	parsefile->lastc[0] = c;
+
+	return c;
+}
+
+
+/*
+ * Same as pgetc(), but ignores PEOA.
+ */
+
+int
+pgetc2()
+{
+	int c;
+	do {
+		c = pgetc();
+	} while (c == PEOA);
+	return c;
+}
+
+
+static int
+preadfd(void)
+{
+	int nr;
+	char *buf =  parsefile->buf;
+	parsefile->nextc = buf;
+
+retry:
+#ifndef SMALL
+	if (parsefile->fd == 0 && el) {
+		static const char *rl_cp;
+		static int el_len;
+
+		if (rl_cp == NULL) {
+			struct stackmark smark;
+			pushstackmark(&smark, stackblocksize());
+			rl_cp = el_gets(el, &el_len);
+			popstackmark(&smark);
+		}
+		if (rl_cp == NULL)
+			nr = 0;
+		else {
+			nr = el_len;
+			if (nr > IBUFSIZ - 1)
+				nr = IBUFSIZ - 1;
+			memcpy(buf, rl_cp, nr);
+			if (nr != el_len) {
+				el_len -= nr;
+				rl_cp += nr;
+			} else
+				rl_cp = 0;
+		}
+
+	} else
+#endif
+		nr = read(parsefile->fd, buf, IBUFSIZ - 1);
+
+
+	if (nr < 0) {
+		if (errno == EINTR)
+			goto retry;
+		if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
+			int flags = fcntl(0, F_GETFL, 0);
+			if (flags >= 0 && flags & O_NONBLOCK) {
+				flags &=~ O_NONBLOCK;
+				if (fcntl(0, F_SETFL, flags) >= 0) {
+					out2str("sh: turning off NDELAY mode\n");
+					goto retry;
+				}
+			}
+		}
+	}
+	return nr;
+}
+
+/*
+ * Refill the input buffer and return the next input character:
+ *
+ * 1) If a string was pushed back on the input, pop it;
+ * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
+ *    from a string so we can't refill the buffer, return EOF.
+ * 3) If the is more stuff in this buffer, use it else call read to fill it.
+ * 4) Process input up to the next newline, deleting nul characters.
+ */
+
+static int preadbuffer(void)
+{
+	char *q;
+	int more;
+#ifndef SMALL
+	int something;
+#endif
+	char savec;
+
+	if (unlikely(parsefile->strpush)) {
+		if (
+			parsefile->nleft == -1 &&
+			parsefile->strpush->ap &&
+			parsefile->nextc[-1] != ' ' &&
+			parsefile->nextc[-1] != '\t'
+		) {
+			return PEOA;
+		}
+		popstring();
+		return pgetc();
+	}
+	if (unlikely(parsefile->nleft == EOF_NLEFT ||
+		     parsefile->buf == NULL))
+		return PEOF;
+	flushall();
+
+	more = parsefile->lleft;
+	if (more <= 0) {
+again:
+		if ((more = preadfd()) <= 0) {
+			parsefile->lleft = parsefile->nleft = EOF_NLEFT;
+			return PEOF;
+		}
+	}
+
+	q = parsefile->nextc;
+
+	/* delete nul characters */
+#ifndef SMALL
+	something = 0;
+#endif
+	for (;;) {
+		int c;
+
+		more--;
+		c = *q;
+
+		if (!c)
+			memmove(q, q + 1, more);
+		else {
+			q++;
+
+			if (c == '\n') {
+				parsefile->nleft = q - parsefile->nextc - 1;
+				break;
+			}
+
+#ifndef SMALL
+			switch (c) {
+			default:
+				something = 1;
+				/* fall through */
+			case '\t':
+			case ' ':
+				break;
+			}
+#endif
+		}
+
+		if (more <= 0) {
+			parsefile->nleft = q - parsefile->nextc - 1;
+			if (parsefile->nleft < 0)
+				goto again;
+			break;
+		}
+	}
+	parsefile->lleft = more;
+
+	savec = *q;
+	*q = '\0';
+
+#ifndef SMALL
+	if (parsefile->fd == 0 && hist && something) {
+		HistEvent he;
+		INTOFF;
+		history(hist, &he, whichprompt == 1? H_ENTER : H_APPEND,
+			parsefile->nextc);
+		INTON;
+	}
+#endif
+
+	if (vflag) {
+		out2str(parsefile->nextc);
+#ifdef FLUSHERR
+		flushout(out2);
+#endif
+	}
+
+	*q = savec;
+
+	return (signed char)*parsefile->nextc++;
+}
+
+/*
+ * Undo a call to pgetc.  Only two characters may be pushed back.
+ * PEOF may be pushed back.
+ */
+
+void
+pungetc(void)
+{
+	parsefile->unget++;
+}
+
+/*
+ * Push a string back onto the input at this current parsefile level.
+ * We handle aliases this way.
+ */
+void
+pushstring(char *s, void *ap)
+{
+	struct strpush *sp;
+	size_t len;
+
+	len = strlen(s);
+	INTOFF;
+/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
+	if (parsefile->strpush) {
+		sp = ckmalloc(sizeof (struct strpush));
+		sp->prev = parsefile->strpush;
+		parsefile->strpush = sp;
+	} else
+		sp = parsefile->strpush = &(parsefile->basestrpush);
+	sp->prevstring = parsefile->nextc;
+	sp->prevnleft = parsefile->nleft;
+	sp->unget = parsefile->unget;
+	memcpy(sp->lastc, parsefile->lastc, sizeof(sp->lastc));
+	sp->ap = (struct alias *)ap;
+	if (ap) {
+		((struct alias *)ap)->flag |= ALIASINUSE;
+		sp->string = s;
+	}
+	parsefile->nextc = s;
+	parsefile->nleft = len;
+	parsefile->unget = 0;
+	INTON;
+}
+
+void
+popstring(void)
+{
+	struct strpush *sp = parsefile->strpush;
+
+	INTOFF;
+	if (sp->ap) {
+		if (parsefile->nextc[-1] == ' ' ||
+		    parsefile->nextc[-1] == '\t') {
+			checkkwd |= CHKALIAS;
+		}
+		if (sp->string != sp->ap->val) {
+			ckfree(sp->string);
+		}
+		sp->ap->flag &= ~ALIASINUSE;
+		if (sp->ap->flag & ALIASDEAD) {
+			unalias(sp->ap->name);
+		}
+	}
+	parsefile->nextc = sp->prevstring;
+	parsefile->nleft = sp->prevnleft;
+	parsefile->unget = sp->unget;
+	memcpy(parsefile->lastc, sp->lastc, sizeof(sp->lastc));
+/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
+	parsefile->strpush = sp->prev;
+	if (sp != &(parsefile->basestrpush))
+		ckfree(sp);
+	INTON;
+}
+
+/*
+ * Set the input to take input from a file.  If push is set, push the
+ * old input onto the stack first.
+ */
+
+int
+setinputfile(const char *fname, int flags)
+{
+	int fd;
+
+	INTOFF;
+	if ((fd = open64(fname, O_RDONLY)) < 0) {
+		if (flags & INPUT_NOFILE_OK)
+			goto out;
+		exitstatus = 127;
+		exerror(EXERROR, "Can't open %s", fname);
+	}
+	if (fd < 10)
+		fd = savefd(fd, fd);
+	setinputfd(fd, flags & INPUT_PUSH_FILE);
+out:
+	INTON;
+	return fd;
+}
+
+
+/*
+ * Like setinputfile, but takes an open file descriptor.  Call this with
+ * interrupts off.
+ */
+
+static void
+setinputfd(int fd, int push)
+{
+	if (push) {
+		pushfile();
+		parsefile->buf = 0;
+	}
+	parsefile->fd = fd;
+	if (parsefile->buf == NULL)
+		parsefile->buf = ckmalloc(IBUFSIZ);
+	parsefile->lleft = parsefile->nleft = 0;
+	plinno = 1;
+}
+
+
+/*
+ * Like setinputfile, but takes input from a string.
+ */
+
+void
+setinputstring(char *string)
+{
+	INTOFF;
+	pushfile();
+	parsefile->nextc = string;
+	parsefile->nleft = strlen(string);
+	parsefile->buf = NULL;
+	plinno = 1;
+	INTON;
+}
+
+
+
+/*
+ * To handle the "." command, a stack of input files is used.  Pushfile
+ * adds a new entry to the stack and popfile restores the previous level.
+ */
+
+STATIC void
+pushfile(void)
+{
+	struct parsefile *pf;
+
+	pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
+	pf->prev = parsefile;
+	pf->fd = -1;
+	pf->strpush = NULL;
+	pf->basestrpush.prev = NULL;
+	pf->unget = 0;
+	parsefile = pf;
+}
+
+
+void
+popfile(void)
+{
+	struct parsefile *pf = parsefile;
+
+	INTOFF;
+	if (pf->fd >= 0)
+		close(pf->fd);
+	if (pf->buf)
+		ckfree(pf->buf);
+	while (pf->strpush)
+		popstring();
+	parsefile = pf->prev;
+	ckfree(pf);
+	INTON;
+}
+
+
+void unwindfiles(struct parsefile *stop)
+{
+	while (parsefile != stop)
+		popfile();
+}
+
+
+/*
+ * Return to top level.
+ */
+
+void
+popallfiles(void)
+{
+	unwindfiles(&basepf);
+}
diff --git a/src/input.h b/src/input.h
new file mode 100644
index 00000000..8acc6e9f
--- /dev/null
+++ b/src/input.h
@@ -0,0 +1,101 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)input.h	8.2 (Berkeley) 5/4/95
+ */
+
+/* PEOF (the end of file marker) is defined in syntax.h */
+
+enum {
+	INPUT_PUSH_FILE = 1,
+	INPUT_NOFILE_OK = 2,
+};
+
+struct alias;
+
+struct strpush {
+	struct strpush *prev;	/* preceding string on stack */
+	char *prevstring;
+	int prevnleft;
+	struct alias *ap;	/* if push was associated with an alias */
+	char *string;		/* remember the string since it may change */
+
+	/* Remember last two characters for pungetc. */
+	int lastc[2];
+
+	/* Number of outstanding calls to pungetc. */
+	int unget;
+};
+
+/*
+ * The parsefile structure pointed to by the global variable parsefile
+ * contains information about the current file being read.
+ */
+
+struct parsefile {
+	struct parsefile *prev;	/* preceding file on stack */
+	int linno;		/* current line */
+	int fd;			/* file descriptor (or -1 if string) */
+	int nleft;		/* number of chars left in this line */
+	int lleft;		/* number of chars left in this buffer */
+	char *nextc;		/* next char in buffer */
+	char *buf;		/* input buffer */
+	struct strpush *strpush; /* for pushing strings at this level */
+	struct strpush basestrpush; /* so pushing one is fast */
+
+	/* Remember last two characters for pungetc. */
+	int lastc[2];
+
+	/* Number of outstanding calls to pungetc. */
+	int unget;
+};
+
+extern struct parsefile *parsefile;
+
+/*
+ * The input line number.  Input.c just defines this variable, and saves
+ * and restores it when files are pushed and popped.  The user of this
+ * package must set its value.
+ */
+#define plinno (parsefile->linno)
+
+int pgetc(void);
+int pgetc2(void);
+void pungetc(void);
+void pushstring(char *, void *);
+void popstring(void);
+int setinputfile(const char *, int);
+void setinputstring(char *);
+void popfile(void);
+void unwindfiles(struct parsefile *);
+void popallfiles(void);
diff --git a/src/jobs.c b/src/jobs.c
new file mode 100644
index 00000000..d4c13c0f
--- /dev/null
+++ b/src/jobs.c
@@ -0,0 +1,1545 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <fcntl.h>
+#include <signal.h>
+#include <unistd.h>
+#include <stdlib.h>
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+#include <sys/types.h>
+#include <sys/param.h>
+#ifdef BSD
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#endif
+#include <sys/ioctl.h>
+
+#include "shell.h"
+#if JOBS
+#include <termios.h>
+#undef CEOF			/* syntax.h redefines this */
+#endif
+#include "exec.h"
+#include "eval.h"
+#include "init.h"
+#include "redir.h"
+#include "show.h"
+#include "main.h"
+#include "parser.h"
+#include "nodes.h"
+#include "jobs.h"
+#include "options.h"
+#include "trap.h"
+#include "syntax.h"
+#include "input.h"
+#include "output.h"
+#include "memalloc.h"
+#include "error.h"
+#include "mystring.h"
+#include "system.h"
+
+/* mode flags for set_curjob */
+#define CUR_DELETE 2
+#define CUR_RUNNING 1
+#define CUR_STOPPED 0
+
+/* mode flags for dowait */
+#define DOWAIT_NONBLOCK 0
+#define DOWAIT_BLOCK 1
+#define DOWAIT_WAITCMD 2
+
+/* array of jobs */
+static struct job *jobtab;
+/* size of array */
+static unsigned njobs;
+/* pid of last background process */
+pid_t backgndpid;
+
+#if JOBS
+/* pgrp of shell on invocation */
+static int initialpgrp;
+/* control terminal */
+static int ttyfd = -1;
+#endif
+
+/* current job */
+static struct job *curjob;
+
+/* Set if we are in the vforked child */
+int vforked;
+
+STATIC void set_curjob(struct job *, unsigned);
+STATIC int jobno(const struct job *);
+STATIC int sprint_status(char *, int, int);
+STATIC void freejob(struct job *);
+STATIC struct job *getjob(const char *, int);
+STATIC struct job *growjobtab(void);
+STATIC void forkchild(struct job *, union node *, int);
+STATIC void forkparent(struct job *, union node *, int, pid_t);
+STATIC int dowait(int, struct job *);
+#ifdef SYSV
+STATIC int onsigchild(void);
+#endif
+STATIC int waitproc(int, int *);
+STATIC char *commandtext(union node *);
+STATIC void cmdtxt(union node *);
+STATIC void cmdlist(union node *, int);
+STATIC void cmdputs(const char *);
+STATIC void showpipe(struct job *, struct output *);
+STATIC int getstatus(struct job *);
+
+#if JOBS
+static int restartjob(struct job *, int);
+static void xtcsetpgrp(int, pid_t);
+#endif
+
+STATIC void
+set_curjob(struct job *jp, unsigned mode)
+{
+	struct job *jp1;
+	struct job **jpp, **curp;
+
+	/* first remove from list */
+	jpp = curp = &curjob;
+	do {
+		jp1 = *jpp;
+		if (jp1 == jp)
+			break;
+		jpp = &jp1->prev_job;
+	} while (1);
+	*jpp = jp1->prev_job;
+
+	/* Then re-insert in correct position */
+	jpp = curp;
+	switch (mode) {
+	default:
+#ifdef DEBUG
+		abort();
+#endif
+	case CUR_DELETE:
+		/* job being deleted */
+		break;
+	case CUR_RUNNING:
+		/* newly created job or backgrounded job,
+		   put after all stopped jobs. */
+		do {
+			jp1 = *jpp;
+			if (!JOBS || !jp1 || jp1->state != JOBSTOPPED)
+				break;
+			jpp = &jp1->prev_job;
+		} while (1);
+		/* FALLTHROUGH */
+#if JOBS
+	case CUR_STOPPED:
+#endif
+		/* newly stopped job - becomes curjob */
+		jp->prev_job = *jpp;
+		*jpp = jp;
+		break;
+	}
+}
+
+#if JOBS
+/*
+ * Turn job control on and off.
+ *
+ * Note:  This code assumes that the third arg to ioctl is a character
+ * pointer, which is true on Berkeley systems but not System V.  Since
+ * System V doesn't have job control yet, this isn't a problem now.
+ *
+ * Called with interrupts off.
+ */
+
+int jobctl;
+
+void
+setjobctl(int on)
+{
+	int fd;
+	int pgrp;
+
+	if (on == jobctl || rootshell == 0)
+		return;
+	if (on) {
+		int ofd;
+		ofd = fd = open64(_PATH_TTY, O_RDWR);
+		if (fd < 0) {
+			fd += 3;
+			while (!isatty(fd))
+				if (--fd < 0)
+					goto out;
+		}
+		fd = savefd(fd, ofd);
+		do { /* while we are in the background */
+			if ((pgrp = tcgetpgrp(fd)) < 0) {
+out:
+				sh_warnx("can't access tty; job control turned off");
+				mflag = on = 0;
+				goto close;
+			}
+			if (pgrp == getpgrp())
+				break;
+			killpg(0, SIGTTIN);
+		} while (1);
+		initialpgrp = pgrp;
+
+		setsignal(SIGTSTP);
+		setsignal(SIGTTOU);
+		setsignal(SIGTTIN);
+		pgrp = rootpid;
+		setpgid(0, pgrp);
+		xtcsetpgrp(fd, pgrp);
+	} else {
+		/* turning job control off */
+		fd = ttyfd;
+		pgrp = initialpgrp;
+		xtcsetpgrp(fd, pgrp);
+		setpgid(0, pgrp);
+		setsignal(SIGTSTP);
+		setsignal(SIGTTOU);
+		setsignal(SIGTTIN);
+close:
+		close(fd);
+		fd = -1;
+	}
+	ttyfd = fd;
+	jobctl = on;
+}
+#endif
+
+
+int
+killcmd(argc, argv)
+	int argc;
+	char **argv;
+{
+	extern char *signal_names[];
+	int signo = -1;
+	int list = 0;
+	int i;
+	pid_t pid;
+	struct job *jp;
+
+	if (argc <= 1) {
+usage:
+		sh_error(
+"Usage: kill [-s sigspec | -signum | -sigspec] [pid | job]... or\n"
+"kill -l [exitstatus]"
+		);
+	}
+
+	if (**++argv == '-') {
+		signo = decode_signal(*argv + 1, 1);
+		if (signo < 0) {
+			int c;
+
+			while ((c = nextopt("ls:")) != '\0')
+				switch (c) {
+				default:
+#ifdef DEBUG
+					abort();
+#endif
+				case 'l':
+					list = 1;
+					break;
+				case 's':
+					signo = decode_signal(optionarg, 1);
+					if (signo < 0) {
+						sh_error(
+							"invalid signal number or name: %s",
+							optionarg
+						);
+					}
+		                        break;
+				}
+			argv = argptr;
+		} else
+			argv++;
+	}
+
+	if (!list && signo < 0)
+		signo = SIGTERM;
+
+	if ((signo < 0 || !*argv) ^ list) {
+		goto usage;
+	}
+
+	if (list) {
+		struct output *out;
+
+		out = out1;
+		if (!*argv) {
+			outstr("0\n", out);
+			for (i = 1; i < NSIG; i++) {
+				outfmt(out, snlfmt, signal_names[i]);
+			}
+			return 0;
+		}
+		signo = number(*argv);
+		if (signo > 128)
+			signo -= 128;
+		if (0 < signo && signo < NSIG)
+			outfmt(out, snlfmt, signal_names[signo]);
+		else
+			sh_error("invalid signal number or exit status: %s",
+				 *argv);
+		return 0;
+	}
+
+	i = 0;
+	do {
+		if (**argv == '%') {
+			jp = getjob(*argv, 0);
+			pid = -jp->ps[0].pid;
+		} else
+			pid = **argv == '-' ?
+				-number(*argv + 1) : number(*argv);
+		if (kill(pid, signo) != 0) {
+			sh_warnx("%s\n", strerror(errno));
+			i = 1;
+		}
+	} while (*++argv);
+
+	return i;
+}
+
+STATIC int
+jobno(const struct job *jp)
+{
+	return jp - jobtab + 1;
+}
+
+#if JOBS
+int
+fgcmd(int argc, char **argv)
+{
+	struct job *jp;
+	struct output *out;
+	int mode;
+	int retval;
+
+	mode = (**argv == 'f') ? FORK_FG : FORK_BG;
+	nextopt(nullstr);
+	argv = argptr;
+	out = out1;
+	do {
+		jp = getjob(*argv, 1);
+		if (mode == FORK_BG) {
+			set_curjob(jp, CUR_RUNNING);
+			outfmt(out, "[%d] ", jobno(jp));
+		}
+		outstr(jp->ps->cmd, out);
+		showpipe(jp, out);
+		retval = restartjob(jp, mode);
+	} while (*argv && *++argv);
+	return retval;
+}
+
+int bgcmd(int argc, char **argv)
+#ifdef HAVE_ALIAS_ATTRIBUTE
+	__attribute__((__alias__("fgcmd")));
+#else
+{
+	return fgcmd(argc, argv);
+}
+#endif
+
+
+STATIC int
+restartjob(struct job *jp, int mode)
+{
+	struct procstat *ps;
+	int i;
+	int status;
+	pid_t pgid;
+
+	INTOFF;
+	if (jp->state == JOBDONE)
+		goto out;
+	jp->state = JOBRUNNING;
+	pgid = jp->ps->pid;
+	if (mode == FORK_FG)
+		xtcsetpgrp(ttyfd, pgid);
+	killpg(pgid, SIGCONT);
+	ps = jp->ps;
+	i = jp->nprocs;
+	do {
+		if (WIFSTOPPED(ps->status)) {
+			ps->status = -1;
+		}
+	} while (ps++, --i);
+out:
+	status = (mode == FORK_FG) ? waitforjob(jp) : 0;
+	INTON;
+	return status;
+}
+#endif
+
+STATIC int
+sprint_status(char *os, int status, int sigonly)
+{
+	char *s = os;
+	int st;
+
+	st = WEXITSTATUS(status);
+	if (!WIFEXITED(status)) {
+#if JOBS
+		st = WSTOPSIG(status);
+		if (!WIFSTOPPED(status))
+#endif
+			st = WTERMSIG(status);
+		if (sigonly) {
+			if (st == SIGINT || st == SIGPIPE)
+				goto out;
+#if JOBS
+			if (WIFSTOPPED(status))
+				goto out;
+#endif
+		}
+		s = stpncpy(s, strsignal(st), 32);
+#ifdef WCOREDUMP
+		if (WCOREDUMP(status)) {
+			s = stpcpy(s, " (core dumped)");
+		}
+#endif
+	} else if (!sigonly) {
+		if (st)
+			s += fmtstr(s, 16, "Done(%d)", st);
+		else
+			s = stpcpy(s, "Done");
+	}
+
+out:
+	return s - os;
+}
+
+static void
+showjob(struct output *out, struct job *jp, int mode)
+{
+	struct procstat *ps;
+	struct procstat *psend;
+	int col;
+	int indent;
+	char s[80];
+
+	ps = jp->ps;
+
+	if (mode & SHOW_PGID) {
+		/* just output process (group) id of pipeline */
+		outfmt(out, "%d\n", ps->pid);
+		return;
+	}
+
+	col = fmtstr(s, 16, "[%d]   ", jobno(jp));
+	indent = col;
+
+	if (jp == curjob)
+		s[col - 2] = '+';
+	else if (curjob && jp == curjob->prev_job)
+		s[col - 2] = '-';
+
+	if (mode & SHOW_PID)
+		col += fmtstr(s + col, 16, "%d ", ps->pid);
+
+	psend = ps + jp->nprocs;
+
+	if (jp->state == JOBRUNNING) {
+		scopy("Running", s + col);
+		col += strlen("Running");
+	} else {
+		int status = psend[-1].status;
+#if JOBS
+		if (jp->state == JOBSTOPPED)
+			status = jp->stopstatus;
+#endif
+		col += sprint_status(s + col, status, 0);
+	}
+
+	goto start;
+
+	do {
+		/* for each process */
+		col = fmtstr(s, 48, " |\n%*c%d ", indent, ' ', ps->pid) - 3;
+
+start:
+		outfmt(
+			out, "%s%*c%s",
+			s, 33 - col >= 0 ? 33 - col : 0, ' ', ps->cmd
+		);
+		if (!(mode & SHOW_PID)) {
+			showpipe(jp, out);
+			break;
+		}
+		if (++ps == psend) {
+			outcslow('\n', out);
+			break;
+		}
+	} while (1);
+
+	jp->changed = 0;
+
+	if (jp->state == JOBDONE) {
+		TRACE(("showjob: freeing job %d\n", jobno(jp)));
+		freejob(jp);
+	}
+}
+
+
+int
+jobscmd(int argc, char **argv)
+{
+	int mode, m;
+	struct output *out;
+
+	mode = 0;
+	while ((m = nextopt("lp")))
+		if (m == 'l')
+			mode = SHOW_PID;
+		else
+			mode = SHOW_PGID;
+
+	out = out1;
+	argv = argptr;
+	if (*argv)
+		do
+			showjob(out, getjob(*argv,0), mode);
+		while (*++argv);
+	else
+		showjobs(out, mode);
+
+	return 0;
+}
+
+
+/*
+ * Print a list of jobs.  If "change" is nonzero, only print jobs whose
+ * statuses have changed since the last call to showjobs.
+ */
+
+void
+showjobs(struct output *out, int mode)
+{
+	struct job *jp;
+
+	TRACE(("showjobs(%x) called\n", mode));
+
+	/* If not even one job changed, there is nothing to do */
+	dowait(DOWAIT_NONBLOCK, NULL);
+
+	for (jp = curjob; jp; jp = jp->prev_job) {
+		if (!(mode & SHOW_CHANGED) || jp->changed)
+			showjob(out, jp, mode);
+	}
+}
+
+/*
+ * Mark a job structure as unused.
+ */
+
+STATIC void
+freejob(struct job *jp)
+{
+	struct procstat *ps;
+	int i;
+
+	INTOFF;
+	for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) {
+		if (ps->cmd != nullstr)
+			ckfree(ps->cmd);
+	}
+	if (jp->ps != &jp->ps0)
+		ckfree(jp->ps);
+	jp->used = 0;
+	set_curjob(jp, CUR_DELETE);
+	INTON;
+}
+
+
+
+int
+waitcmd(int argc, char **argv)
+{
+	struct job *job;
+	int retval;
+	struct job *jp;
+
+	nextopt(nullstr);
+	retval = 0;
+
+	argv = argptr;
+	if (!*argv) {
+		/* wait for all jobs */
+		for (;;) {
+			jp = curjob;
+			while (1) {
+				if (!jp) {
+					/* no running procs */
+					goto out;
+				}
+				if (jp->state == JOBRUNNING)
+					break;
+				jp->waited = 1;
+				jp = jp->prev_job;
+			}
+			if (!dowait(DOWAIT_WAITCMD, 0))
+				goto sigout;
+		}
+	}
+
+	retval = 127;
+	do {
+		if (**argv != '%') {
+			pid_t pid = number(*argv);
+			job = curjob;
+			goto start;
+			do {
+				if (job->ps[job->nprocs - 1].pid == pid)
+					break;
+				job = job->prev_job;
+start:
+				if (!job)
+					goto repeat;
+			} while (1);
+		} else
+			job = getjob(*argv, 0);
+		/* loop until process terminated or stopped */
+		if (!dowait(DOWAIT_WAITCMD, job))
+			goto sigout;
+		job->waited = 1;
+		retval = getstatus(job);
+repeat:
+		;
+	} while (*++argv);
+
+out:
+	return retval;
+
+sigout:
+	retval = 128 + pending_sig;
+	goto out;
+}
+
+
+
+/*
+ * Convert a job name to a job structure.
+ */
+
+STATIC struct job *
+getjob(const char *name, int getctl)
+{
+	struct job *jp;
+	struct job *found;
+	const char *err_msg = "No such job: %s";
+	unsigned num;
+	int c;
+	const char *p;
+	char *(*match)(const char *, const char *);
+
+	jp = curjob;
+	p = name;
+	if (!p)
+		goto currentjob;
+
+	if (*p != '%')
+		goto err;
+
+	c = *++p;
+	if (!c)
+		goto currentjob;
+
+	if (!p[1]) {
+		if (c == '+' || c == '%') {
+currentjob:
+			err_msg = "No current job";
+			goto check;
+		} else if (c == '-') {
+			if (jp)
+				jp = jp->prev_job;
+			err_msg = "No previous job";
+check:
+			if (!jp)
+				goto err;
+			goto gotit;
+		}
+	}
+
+	if (is_number(p)) {
+		num = atoi(p);
+		if (num > 0 && num <= njobs) {
+			jp = jobtab + num - 1;
+			if (jp->used)
+				goto gotit;
+			goto err;
+		}
+	}
+
+	match = prefix;
+	if (*p == '?') {
+		match = strstr;
+		p++;
+	}
+
+	found = 0;
+	while (jp) {
+		if (match(jp->ps[0].cmd, p)) {
+			if (found)
+				goto err;
+			found = jp;
+			err_msg = "%s: ambiguous";
+		}
+		jp = jp->prev_job;
+	}
+
+	if (!found)
+		goto err;
+	jp = found;
+
+gotit:
+#if JOBS
+	err_msg = "job %s not created under job control";
+	if (getctl && jp->jobctl == 0)
+		goto err;
+#endif
+	return jp;
+err:
+	sh_error(err_msg, name);
+}
+
+
+
+/*
+ * Return a new job structure.
+ * Called with interrupts off.
+ */
+
+struct job *
+makejob(union node *node, int nprocs)
+{
+	int i;
+	struct job *jp;
+
+	for (i = njobs, jp = jobtab ; ; jp++) {
+		if (--i < 0) {
+			jp = growjobtab();
+			break;
+		}
+		if (jp->used == 0)
+			break;
+		if (jp->state != JOBDONE || !jp->waited)
+			continue;
+		if (jobctl)
+			continue;
+		freejob(jp);
+		break;
+	}
+	memset(jp, 0, sizeof(*jp));
+#if JOBS
+	if (jobctl)
+		jp->jobctl = 1;
+#endif
+	jp->prev_job = curjob;
+	curjob = jp;
+	jp->used = 1;
+	jp->ps = &jp->ps0;
+	if (nprocs > 1) {
+		jp->ps = ckmalloc(nprocs * sizeof (struct procstat));
+	}
+	TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs,
+	    jobno(jp)));
+	return jp;
+}
+
+STATIC struct job *
+growjobtab(void)
+{
+	size_t len;
+	ptrdiff_t offset;
+	struct job *jp, *jq;
+
+	len = njobs * sizeof(*jp);
+	jq = jobtab;
+	jp = ckrealloc(jq, len + 4 * sizeof(*jp));
+
+	offset = (char *)jp - (char *)jq;
+	if (offset) {
+		/* Relocate pointers */
+		size_t l = len;
+
+		jq = (struct job *)((char *)jq + l);
+		while (l) {
+			l -= sizeof(*jp);
+			jq--;
+#define joff(p) ((struct job *)((char *)(p) + l))
+#define jmove(p) (p) = (void *)((char *)(p) + offset)
+			if (likely(joff(jp)->ps == &jq->ps0))
+				jmove(joff(jp)->ps);
+			if (joff(jp)->prev_job)
+				jmove(joff(jp)->prev_job);
+		}
+		if (curjob)
+			jmove(curjob);
+#undef joff
+#undef jmove
+	}
+
+	njobs += 4;
+	jobtab = jp;
+	jp = (struct job *)((char *)jp + len);
+	jq = jp + 3;
+	do {
+		jq->used = 0;
+	} while (--jq >= jp);
+	return jp;
+}
+
+
+/*
+ * Fork off a subshell.  If we are doing job control, give the subshell its
+ * own process group.  Jp is a job structure that the job is to be added to.
+ * N is the command that will be evaluated by the child.  Both jp and n may
+ * be NULL.  The mode parameter can be one of the following:
+ *	FORK_FG - Fork off a foreground process.
+ *	FORK_BG - Fork off a background process.
+ *	FORK_NOJOB - Like FORK_FG, but don't give the process its own
+ *		     process group even if job control is on.
+ *
+ * When job control is turned off, background processes have their standard
+ * input redirected to /dev/null (except for the second and later processes
+ * in a pipeline).
+ *
+ * Called with interrupts off.
+ */
+
+static void forkchild(struct job *jp, union node *n, int mode)
+{
+	int lvforked;
+	int oldlvl;
+
+	TRACE(("Child shell %d\n", getpid()));
+
+	oldlvl = shlvl;
+	lvforked = vforked;
+
+	if (!lvforked) {
+		shlvl++;
+
+		forkreset();
+
+#if JOBS
+		/* do job control only in root shell */
+		jobctl = 0;
+#endif
+	}
+
+#if JOBS
+	if (mode != FORK_NOJOB && jp->jobctl && !oldlvl) {
+		pid_t pgrp;
+
+		if (jp->nprocs == 0)
+			pgrp = getpid();
+		else
+			pgrp = jp->ps[0].pid;
+		/* This can fail because we are doing it in the parent also */
+		(void)setpgid(0, pgrp);
+		if (mode == FORK_FG)
+			xtcsetpgrp(ttyfd, pgrp);
+		setsignal(SIGTSTP);
+		setsignal(SIGTTOU);
+	} else
+#endif
+	if (mode == FORK_BG) {
+		ignoresig(SIGINT);
+		ignoresig(SIGQUIT);
+		if (jp->nprocs == 0) {
+			close(0);
+			if (open64(_PATH_DEVNULL, O_RDONLY) != 0)
+				sh_error("Can't open %s", _PATH_DEVNULL);
+		}
+	}
+	if (!oldlvl && iflag) {
+		if (mode != FORK_BG) {
+			setsignal(SIGINT);
+			setsignal(SIGQUIT);
+		}
+		setsignal(SIGTERM);
+	}
+
+	if (lvforked)
+		return;
+
+	for (jp = curjob; jp; jp = jp->prev_job)
+		freejob(jp);
+}
+
+static void forkparent(struct job *jp, union node *n, int mode, pid_t pid)
+{
+	if (pid < 0) {
+		TRACE(("Fork failed, errno=%d", errno));
+		if (jp)
+			freejob(jp);
+		sh_error("Cannot fork");
+		/* NOTREACHED */
+	}
+
+	TRACE(("In parent shell:  child = %d\n", pid));
+	if (!jp)
+		return;
+#if JOBS
+	if (mode != FORK_NOJOB && jp->jobctl) {
+		int pgrp;
+
+		if (jp->nprocs == 0)
+			pgrp = pid;
+		else
+			pgrp = jp->ps[0].pid;
+		/* This can fail because we are doing it in the child also */
+		(void)setpgid(pid, pgrp);
+	}
+#endif
+	if (mode == FORK_BG) {
+		backgndpid = pid;		/* set $! */
+		set_curjob(jp, CUR_RUNNING);
+	}
+	if (jp) {
+		struct procstat *ps = &jp->ps[jp->nprocs++];
+		ps->pid = pid;
+		ps->status = -1;
+		ps->cmd = nullstr;
+		if (jobctl && n)
+			ps->cmd = commandtext(n);
+	}
+}
+
+int
+forkshell(struct job *jp, union node *n, int mode)
+{
+	int pid;
+
+	TRACE(("forkshell(%%%d, %p, %d) called\n", jobno(jp), n, mode));
+	pid = fork();
+	if (pid == 0)
+		forkchild(jp, n, mode);
+	else
+		forkparent(jp, n, mode, pid);
+
+	return pid;
+}
+
+struct job *vforkexec(union node *n, char **argv, const char *path, int idx)
+{
+	struct job *jp;
+	int pid;
+
+	jp = makejob(n, 1);
+
+	sigblockall(NULL);
+	vforked++;
+
+	pid = vfork();
+
+	if (!pid) {
+		forkchild(jp, n, FORK_FG);
+		sigclearmask();
+		shellexec(argv, path, idx);
+		/* NOTREACHED */
+	}
+
+	vforked = 0;
+	sigclearmask();
+	forkparent(jp, n, FORK_FG, pid);
+
+	return jp;
+}
+
+/*
+ * Wait for job to finish.
+ *
+ * Under job control we have the problem that while a child process is
+ * running interrupts generated by the user are sent to the child but not
+ * to the shell.  This means that an infinite loop started by an inter-
+ * active user may be hard to kill.  With job control turned off, an
+ * interactive user may place an interactive program inside a loop.  If
+ * the interactive program catches interrupts, the user doesn't want
+ * these interrupts to also abort the loop.  The approach we take here
+ * is to have the shell ignore interrupt signals while waiting for a
+ * forground process to terminate, and then send itself an interrupt
+ * signal if the child process was terminated by an interrupt signal.
+ * Unfortunately, some programs want to do a bit of cleanup and then
+ * exit on interrupt; unless these processes terminate themselves by
+ * sending a signal to themselves (instead of calling exit) they will
+ * confuse this approach.
+ *
+ * Called with interrupts off.
+ */
+
+int
+waitforjob(struct job *jp)
+{
+	int st;
+
+	TRACE(("waitforjob(%%%d) called\n", jp ? jobno(jp) : 0));
+	dowait(jp ? DOWAIT_BLOCK : DOWAIT_NONBLOCK, jp);
+	if (!jp)
+		return exitstatus;
+
+	st = getstatus(jp);
+#if JOBS
+	if (jp->jobctl) {
+		xtcsetpgrp(ttyfd, rootpid);
+		/*
+		 * This is truly gross.
+		 * If we're doing job control, then we did a TIOCSPGRP which
+		 * caused us (the shell) to no longer be in the controlling
+		 * session -- so we wouldn't have seen any ^C/SIGINT.  So, we
+		 * intuit from the subprocess exit status whether a SIGINT
+		 * occurred, and if so interrupt ourselves.  Yuck.  - mycroft
+		 */
+		if (jp->sigint)
+			raise(SIGINT);
+	}
+#endif
+	if (! JOBS || jp->state == JOBDONE)
+		freejob(jp);
+	return st;
+}
+
+
+
+/*
+ * Wait for a process to terminate.
+ */
+
+static int waitone(int block, struct job *job)
+{
+	int pid;
+	int status;
+	struct job *jp;
+	struct job *thisjob = NULL;
+	int state;
+
+	INTOFF;
+	TRACE(("dowait(%d) called\n", block));
+	pid = waitproc(block, &status);
+	TRACE(("wait returns pid %d, status=%d\n", pid, status));
+	if (pid <= 0)
+		goto out;
+
+	for (jp = curjob; jp; jp = jp->prev_job) {
+		struct procstat *sp;
+		struct procstat *spend;
+		if (jp->state == JOBDONE)
+			continue;
+		state = JOBDONE;
+		spend = jp->ps + jp->nprocs;
+		sp = jp->ps;
+		do {
+			if (sp->pid == pid) {
+				TRACE(("Job %d: changing status of proc %d from 0x%x to 0x%x\n", jobno(jp), pid, sp->status, status));
+				sp->status = status;
+				thisjob = jp;
+			}
+			if (sp->status == -1)
+				state = JOBRUNNING;
+#if JOBS
+			if (state == JOBRUNNING)
+				continue;
+			if (WIFSTOPPED(sp->status)) {
+				jp->stopstatus = sp->status;
+				state = JOBSTOPPED;
+			}
+#endif
+		} while (++sp < spend);
+		if (thisjob)
+			goto gotjob;
+	}
+	goto out;
+
+gotjob:
+	if (state != JOBRUNNING) {
+		thisjob->changed = 1;
+
+		if (thisjob->state != state) {
+			TRACE(("Job %d: changing state from %d to %d\n", jobno(thisjob), thisjob->state, state));
+			thisjob->state = state;
+#if JOBS
+			if (state == JOBSTOPPED) {
+				set_curjob(thisjob, CUR_STOPPED);
+			}
+#endif
+		}
+	}
+
+out:
+	INTON;
+
+	if (thisjob && thisjob == job) {
+		char s[48 + 1];
+		int len;
+
+		len = sprint_status(s, status, 1);
+		if (len) {
+			s[len] = '\n';
+			s[len + 1] = 0;
+			outstr(s, out2);
+		}
+	}
+	return pid;
+}
+
+static int dowait(int block, struct job *jp)
+{
+	int gotchld = *(volatile int *)&gotsigchld;
+	int rpid;
+	int pid;
+
+	if (jp && jp->state != JOBRUNNING)
+		block = DOWAIT_NONBLOCK;
+
+	if (block == DOWAIT_NONBLOCK && !gotchld)
+		return 1;
+
+	rpid = 1;
+
+	do {
+		pid = waitone(block, jp);
+		rpid &= !!pid;
+
+		if (!pid || (jp && jp->state != JOBRUNNING))
+			block = DOWAIT_NONBLOCK;
+	} while (pid >= 0);
+
+	return rpid;
+}
+
+/*
+ * Do a wait system call.  If block is zero, we return -1 rather than
+ * blocking.  If block is DOWAIT_WAITCMD, we return 0 when a signal
+ * other than SIGCHLD interrupted the wait.
+ *
+ * We use sigsuspend in conjunction with a non-blocking wait3 in
+ * order to ensure that waitcmd exits promptly upon the reception
+ * of a signal.
+ *
+ * For code paths other than waitcmd we either use a blocking wait3
+ * or a non-blocking wait3.  For the latter case the caller of dowait
+ * must ensure that it is called over and over again until all dead
+ * children have been reaped.  Otherwise zombies may linger.
+ */
+
+
+STATIC int
+waitproc(int block, int *status)
+{
+	sigset_t oldmask;
+	int flags = block == DOWAIT_BLOCK ? 0 : WNOHANG;
+	int err;
+
+#if JOBS
+	if (jobctl)
+		flags |= WUNTRACED;
+#endif
+
+	do {
+		gotsigchld = 0;
+		do
+			err = wait3(status, flags, NULL);
+		while (err < 0 && errno == EINTR);
+
+		if (err || (err = -!block))
+			break;
+
+		sigblockall(&oldmask);
+
+		while (!gotsigchld && !pending_sig)
+			sigsuspend(&oldmask);
+
+		sigclearmask();
+	} while (gotsigchld);
+
+	return err;
+}
+
+/*
+ * return 1 if there are stopped jobs, otherwise 0
+ */
+int job_warning;
+int
+stoppedjobs(void)
+{
+	struct job *jp;
+	int retval;
+
+	retval = 0;
+	if (job_warning)
+		goto out;
+	jp = curjob;
+	if (jp && jp->state == JOBSTOPPED) {
+		out2str("You have stopped jobs.\n");
+		job_warning = 2;
+		retval++;
+	}
+
+out:
+	return retval;
+}
+
+/*
+ * Return a string identifying a command (to be printed by the
+ * jobs command).
+ */
+
+STATIC char *cmdnextc;
+
+STATIC char *
+commandtext(union node *n)
+{
+	char *name;
+
+	STARTSTACKSTR(cmdnextc);
+	cmdtxt(n);
+	name = stackblock();
+	TRACE(("commandtext: name %p, end %p\n", name, cmdnextc));
+	return savestr(name);
+}
+
+
+STATIC void
+cmdtxt(union node *n)
+{
+	union node *np;
+	struct nodelist *lp;
+	const char *p;
+	char s[2];
+
+	if (!n)
+		return;
+	switch (n->type) {
+	default:
+#if DEBUG
+		abort();
+#endif
+	case NPIPE:
+		lp = n->npipe.cmdlist;
+		for (;;) {
+			cmdtxt(lp->n);
+			lp = lp->next;
+			if (!lp)
+				break;
+			cmdputs(" | ");
+		}
+		break;
+	case NSEMI:
+		p = "; ";
+		goto binop;
+	case NAND:
+		p = " && ";
+		goto binop;
+	case NOR:
+		p = " || ";
+binop:
+		cmdtxt(n->nbinary.ch1);
+		cmdputs(p);
+		n = n->nbinary.ch2;
+		goto donode;
+	case NREDIR:
+	case NBACKGND:
+		n = n->nredir.n;
+		goto donode;
+	case NNOT:
+		cmdputs("!");
+		n = n->nnot.com;
+donode:
+		cmdtxt(n);
+		break;
+	case NIF:
+		cmdputs("if ");
+		cmdtxt(n->nif.test);
+		cmdputs("; then ");
+		if (n->nif.elsepart) {
+			cmdtxt(n->nif.ifpart);
+			cmdputs("; else ");
+			n = n->nif.elsepart;
+		} else {
+			n = n->nif.ifpart;
+		}
+		p = "; fi";
+		goto dotail;
+	case NSUBSHELL:
+		cmdputs("(");
+		n = n->nredir.n;
+		p = ")";
+		goto dotail;
+	case NWHILE:
+		p = "while ";
+		goto until;
+	case NUNTIL:
+		p = "until ";
+until:
+		cmdputs(p);
+		cmdtxt(n->nbinary.ch1);
+		n = n->nbinary.ch2;
+		p = "; done";
+dodo:
+		cmdputs("; do ");
+dotail:
+		cmdtxt(n);
+		goto dotail2;
+	case NFOR:
+		cmdputs("for ");
+		cmdputs(n->nfor.var);
+		cmdputs(" in ");
+		cmdlist(n->nfor.args, 1);
+		n = n->nfor.body;
+		p = "; done";
+		goto dodo;
+	case NDEFUN:
+		cmdputs(n->ndefun.text);
+		p = "() { ... }";
+		goto dotail2;
+	case NCMD:
+		cmdlist(n->ncmd.args, 1);
+		cmdlist(n->ncmd.redirect, 0);
+		break;
+	case NARG:
+		p = n->narg.text;
+dotail2:
+		cmdputs(p);
+		break;
+	case NHERE:
+	case NXHERE:
+		p = "<<...";
+		goto dotail2;
+	case NCASE:
+		cmdputs("case ");
+		cmdputs(n->ncase.expr->narg.text);
+		cmdputs(" in ");
+		for (np = n->ncase.cases; np; np = np->nclist.next) {
+			cmdtxt(np->nclist.pattern);
+			cmdputs(") ");
+			cmdtxt(np->nclist.body);
+			cmdputs(";; ");
+		}
+		p = "esac";
+		goto dotail2;
+	case NTO:
+		p = ">";
+		goto redir;
+	case NCLOBBER:
+		p = ">|";
+		goto redir;
+	case NAPPEND:
+		p = ">>";
+		goto redir;
+	case NTOFD:
+		p = ">&";
+		goto redir;
+	case NFROM:
+		p = "<";
+		goto redir;
+	case NFROMFD:
+		p = "<&";
+		goto redir;
+	case NFROMTO:
+		p = "<>";
+redir:
+		s[0] = n->nfile.fd + '0';
+		s[1] = '\0';
+		cmdputs(s);
+		cmdputs(p);
+		if (n->type == NTOFD || n->type == NFROMFD) {
+			s[0] = n->ndup.dupfd + '0';
+			p = s;
+			goto dotail2;
+		} else {
+			n = n->nfile.fname;
+			goto donode;
+		}
+	}
+}
+
+STATIC void
+cmdlist(union node *np, int sep)
+{
+	for (; np; np = np->narg.next) {
+		if (!sep)
+			cmdputs(spcstr);
+		cmdtxt(np);
+		if (sep && np->narg.next)
+			cmdputs(spcstr);
+	}
+}
+
+
+STATIC void
+cmdputs(const char *s)
+{
+	const char *p, *str;
+	char cc[2] = " ";
+	char *nextc;
+	signed char c;
+	int subtype = 0;
+	int quoted = 0;
+	static const char vstype[VSTYPE + 1][4] = {
+		"", "}", "-", "+", "?", "=",
+		"%", "%%", "#", "##",
+	};
+
+	nextc = makestrspace((strlen(s) + 1) * 8, cmdnextc);
+	p = s;
+	while ((c = *p++) != 0) {
+		str = 0;
+		switch (c) {
+		case CTLESC:
+			c = *p++;
+			break;
+		case CTLVAR:
+			subtype = *p++;
+			if ((subtype & VSTYPE) == VSLENGTH)
+				str = "${#";
+			else
+				str = "${";
+			goto dostr;
+		case CTLENDVAR:
+			str = "\"}";
+			str += !(quoted & 1);
+			quoted >>= 1;
+			subtype = 0;
+			goto dostr;
+		case CTLBACKQ:
+			str = "$(...)";
+			goto dostr;
+		case CTLARI:
+			str = "$((";
+			goto dostr;
+		case CTLENDARI:
+			str = "))";
+			goto dostr;
+		case CTLQUOTEMARK:
+			quoted ^= 1;
+			c = '"';
+			break;
+		case '=':
+			if (subtype == 0)
+				break;
+			if ((subtype & VSTYPE) != VSNORMAL)
+				quoted <<= 1;
+			str = vstype[subtype & VSTYPE];
+			if (subtype & VSNUL)
+				c = ':';
+			else
+				goto checkstr;
+			break;
+		case '\'':
+		case '\\':
+		case '"':
+		case '$':
+			/* These can only happen inside quotes */
+			cc[0] = c;
+			str = cc;
+			c = '\\';
+			break;
+		default:
+			break;
+		}
+		USTPUTC(c, nextc);
+checkstr:
+		if (!str)
+			continue;
+dostr:
+		while ((c = *str++)) {
+			USTPUTC(c, nextc);
+		}
+	}
+	if (quoted & 1) {
+		USTPUTC('"', nextc);
+	}
+	*nextc = 0;
+	cmdnextc = nextc;
+}
+
+
+STATIC void
+showpipe(struct job *jp, struct output *out)
+{
+	struct procstat *sp;
+	struct procstat *spend;
+
+	spend = jp->ps + jp->nprocs;
+	for (sp = jp->ps + 1; sp < spend; sp++)
+		outfmt(out, " | %s", sp->cmd);
+	outcslow('\n', out);
+	flushall();
+}
+
+
+#if JOBS
+STATIC void
+xtcsetpgrp(int fd, pid_t pgrp)
+{
+	if (tcsetpgrp(fd, pgrp))
+		sh_error("Cannot set tty process group (%s)", strerror(errno));
+}
+#endif
+
+
+STATIC int
+getstatus(struct job *job) {
+	int status;
+	int retval;
+
+	status = job->ps[job->nprocs - 1].status;
+	retval = WEXITSTATUS(status);
+	if (!WIFEXITED(status)) {
+#if JOBS
+		retval = WSTOPSIG(status);
+		if (!WIFSTOPPED(status))
+#endif
+		{
+			/* XXX: limits number of signals */
+			retval = WTERMSIG(status);
+#if JOBS
+			if (retval == SIGINT)
+				job->sigint = 1;
+#endif
+		}
+		retval += 128;
+	}
+	TRACE(("getstatus: job %d, nproc %d, status %x, retval %x\n",
+		jobno(job), job->nprocs, status, retval));
+	return retval;
+}
diff --git a/src/jobs.h b/src/jobs.h
new file mode 100644
index 00000000..6ac6c56d
--- /dev/null
+++ b/src/jobs.h
@@ -0,0 +1,113 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)jobs.h	8.2 (Berkeley) 5/4/95
+ */
+
+#include <inttypes.h>
+#include <sys/types.h>
+
+/* Mode argument to forkshell.  Don't change FORK_FG or FORK_BG. */
+#define FORK_FG 0
+#define FORK_BG 1
+#define FORK_NOJOB 2
+
+/* mode flags for showjob(s) */
+#define	SHOW_PGID	0x01	/* only show pgid - for jobs -p */
+#define	SHOW_PID	0x04	/* include process pid */
+#define	SHOW_CHANGED	0x08	/* only jobs whose state has changed */
+
+
+/*
+ * A job structure contains information about a job.  A job is either a
+ * single process or a set of processes contained in a pipeline.  In the
+ * latter case, pidlist will be non-NULL, and will point to a -1 terminated
+ * array of pids.
+ */
+
+struct procstat {
+	pid_t	pid;		/* process id */
+ 	int	status;		/* last process status from wait() */
+ 	char	*cmd;		/* text of command being run */
+};
+
+struct job {
+	struct procstat ps0;	/* status of process */
+	struct procstat *ps;	/* status or processes when more than one */
+#if JOBS
+	int stopstatus;		/* status of a stopped job */
+#endif
+	uint32_t
+		nprocs: 16,	/* number of processes */
+		state: 8,
+#define	JOBRUNNING	0	/* at least one proc running */
+#define	JOBSTOPPED	1	/* all procs are stopped */
+#define	JOBDONE		2	/* all procs are completed */
+#if JOBS
+		sigint: 1,	/* job was killed by SIGINT */
+		jobctl: 1,	/* job running under job control */
+#endif
+		waited: 1,	/* true if this entry has been waited for */
+		used: 1,	/* true if this entry is in used */
+		changed: 1;	/* true if status has changed */
+	struct job *prev_job;	/* previous job */
+};
+
+union node;
+
+extern pid_t backgndpid;	/* pid of last background process */
+extern int job_warning;		/* user was warned about stopped jobs */
+#if JOBS
+extern int jobctl;		/* true if doing job control */
+#else
+#define jobctl 0
+#endif
+extern int vforked;		/* Set if we are in the vforked child */
+
+void setjobctl(int);
+int killcmd(int, char **);
+int fgcmd(int, char **);
+int bgcmd(int, char **);
+int jobscmd(int, char **);
+struct output;
+void showjobs(struct output *, int);
+int waitcmd(int, char **);
+struct job *makejob(union node *, int);
+int forkshell(struct job *, union node *, int);
+struct job *vforkexec(union node *n, char **argv, const char *path, int idx);
+int waitforjob(struct job *);
+int stoppedjobs(void);
+
+#if ! JOBS
+#define setjobctl(on) ((void)(on))	/* do nothing */
+#endif
diff --git a/src/machdep.h b/src/machdep.h
new file mode 100644
index 00000000..f2ff0ad8
--- /dev/null
+++ b/src/machdep.h
@@ -0,0 +1,47 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)machdep.h	8.2 (Berkeley) 5/4/95
+ */
+
+/*
+ * Most machines require the value returned from malloc to be aligned
+ * in some way.  The following macro will get this right on many machines.
+ */
+
+#define SHELL_SIZE (sizeof(union {int i; char *cp; double d; }) - 1)
+/*
+ * It appears that grabstackstr() will barf with such alignments
+ * because stalloc() will return a string allocated in a new stackblock.
+ */
+#define SHELL_ALIGN(nbytes) (((nbytes) + SHELL_SIZE) & ~SHELL_SIZE)
diff --git a/src/mail.c b/src/mail.c
new file mode 100644
index 00000000..8eacb2d0
--- /dev/null
+++ b/src/mail.c
@@ -0,0 +1,115 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Routines to check for mail.  (Perhaps make part of main.c?)
+ */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+
+#include "shell.h"
+#include "nodes.h"
+#include "exec.h"	/* defines padvance() */
+#include "var.h"
+#include "output.h"
+#include "memalloc.h"
+#include "error.h"
+#include "mail.h"
+#include "mystring.h"
+
+
+#define MAXMBOXES 10
+
+/* times of mailboxes */
+static time_t mailtime[MAXMBOXES];
+/* Set if MAIL or MAILPATH is changed. */
+static int changed;
+
+
+
+/*
+ * Print appropriate message(s) if mail has arrived.  If changed is set,
+ * then the value of MAIL has changed, so we just update the values.
+ */
+
+void
+chkmail(void)
+{
+	const char *mpath;
+	char *p;
+	char *q;
+	time_t *mtp;
+	struct stackmark smark;
+	struct stat64 statb;
+
+	setstackmark(&smark);
+	mpath = mpathset() ? mpathval() : mailval();
+	for (mtp = mailtime; mtp < mailtime + MAXMBOXES; mtp++) {
+		int len;
+
+		len = padvance_magic(&mpath, nullstr, 2);
+		if (!len)
+			break;
+		p = stackblock();
+		if (*p == '\0')
+			continue;
+		for (q = p ; *q ; q++);
+#ifdef DEBUG
+		if (q[-1] != '/')
+			abort();
+#endif
+		q[-1] = '\0';			/* delete trailing '/' */
+		if (stat64(p, &statb) < 0) {
+			*mtp = 0;
+			continue;
+		}
+		if (!changed && statb.st_mtime != *mtp) {
+			outfmt(
+				&errout, snlfmt,
+				pathopt ? pathopt : "you have mail"
+			);
+		}
+		*mtp = statb.st_mtime;
+	}
+	changed = 0;
+	popstackmark(&smark);
+}
+
+
+void
+changemail(const char *val)
+{
+	changed++;
+}
diff --git a/src/mail.h b/src/mail.h
new file mode 100644
index 00000000..3c6b21d2
--- /dev/null
+++ b/src/mail.h
@@ -0,0 +1,38 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)mail.h	8.2 (Berkeley) 5/4/95
+ */
+
+void chkmail(void);
+void changemail(const char *);
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 00000000..7a285346
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,363 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <signal.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+
+#include "shell.h"
+#include "main.h"
+#include "mail.h"
+#include "options.h"
+#include "output.h"
+#include "parser.h"
+#include "nodes.h"
+#include "expand.h"
+#include "eval.h"
+#include "jobs.h"
+#include "input.h"
+#include "trap.h"
+#include "var.h"
+#include "show.h"
+#include "memalloc.h"
+#include "error.h"
+#include "init.h"
+#include "mystring.h"
+#include "exec.h"
+#include "cd.h"
+
+#define PROFILE 0
+
+int rootpid;
+int shlvl;
+#ifdef __GLIBC__
+int *dash_errno;
+#endif
+#if PROFILE
+short profile_buf[16384];
+extern int etext();
+#endif
+MKINIT struct jmploc main_handler;
+
+STATIC void read_profile(const char *);
+STATIC char *find_dot_file(char *);
+static int cmdloop(int);
+int main(int, char **);
+
+/*
+ * Main routine.  We initialize things, parse the arguments, execute
+ * profiles if we're a login shell, and then call cmdloop to execute
+ * commands.  The setjmp call sets up the location to jump to when an
+ * exception occurs.  When an exception occurs the variable "state"
+ * is used to figure out how far we had gotten.
+ */
+
+int
+main(int argc, char **argv)
+{
+	char *shinit;
+	volatile int state;
+	struct stackmark smark;
+	int login;
+
+#ifdef __GLIBC__
+	dash_errno = __errno_location();
+#endif
+
+#if PROFILE
+	monitor(4, etext, profile_buf, sizeof profile_buf, 50);
+#endif
+	state = 0;
+	if (unlikely(setjmp(main_handler.loc))) {
+		int e;
+		int s;
+
+		exitreset();
+
+		e = exception;
+
+		s = state;
+		if (e == EXEND || e == EXEXIT || s == 0 || iflag == 0 || shlvl)
+			exitshell();
+
+		reset();
+
+		if (e == EXINT
+#if ATTY
+		 && (! attyset() || equal(termval(), "emacs"))
+#endif
+		 ) {
+			out2c('\n');
+#ifdef FLUSHERR
+			flushout(out2);
+#endif
+		}
+		popstackmark(&smark);
+		FORCEINTON;				/* enable interrupts */
+		if (s == 1)
+			goto state1;
+		else if (s == 2)
+			goto state2;
+		else if (s == 3)
+			goto state3;
+		else
+			goto state4;
+	}
+	handler = &main_handler;
+#ifdef DEBUG
+	opentrace();
+	trputs("Shell args:  ");  trargs(argv);
+#endif
+	rootpid = getpid();
+	init();
+	setstackmark(&smark);
+	login = procargs(argc, argv);
+	if (login) {
+		state = 1;
+		read_profile("/etc/profile");
+state1:
+		state = 2;
+		read_profile("$HOME/.profile");
+	}
+state2:
+	state = 3;
+	if (
+#ifndef linux
+		getuid() == geteuid() && getgid() == getegid() &&
+#endif
+		iflag
+	) {
+		if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
+			read_profile(shinit);
+		}
+	}
+	popstackmark(&smark);
+state3:
+	state = 4;
+	if (minusc)
+		evalstring(minusc, sflag ? 0 : EV_EXIT);
+
+	if (sflag || minusc == NULL) {
+state4:	/* XXX ??? - why isn't this before the "if" statement */
+		cmdloop(1);
+	}
+#if PROFILE
+	monitor(0);
+#endif
+#if GPROF
+	{
+		extern void _mcleanup(void);
+		_mcleanup();
+	}
+#endif
+	exitshell();
+	/* NOTREACHED */
+}
+
+
+/*
+ * Read and execute commands.  "Top" is nonzero for the top level command
+ * loop; it turns on prompting if the shell is interactive.
+ */
+
+static int
+cmdloop(int top)
+{
+	union node *n;
+	struct stackmark smark;
+	int inter;
+	int status = 0;
+	int numeof = 0;
+
+	TRACE(("cmdloop(%d) called\n", top));
+	for (;;) {
+		int skip;
+
+		setstackmark(&smark);
+		if (jobctl)
+			showjobs(out2, SHOW_CHANGED);
+		inter = 0;
+		if (iflag && top) {
+			inter++;
+			chkmail();
+		}
+		n = parsecmd(inter);
+		/* showtree(n); DEBUG */
+		if (n == NEOF) {
+			if (!top || numeof >= 50)
+				break;
+			if (!stoppedjobs()) {
+				if (!Iflag) {
+					if (iflag) {
+						out2c('\n');
+#ifdef FLUSHERR
+						flushout(out2);
+#endif
+					}
+					break;
+				}
+				out2str("\nUse \"exit\" to leave shell.\n");
+			}
+			numeof++;
+		} else if (nflag == 0) {
+			int i;
+
+			job_warning = (job_warning == 2) ? 1 : 0;
+			numeof = 0;
+			i = evaltree(n, 0);
+			if (n)
+				status = i;
+		}
+		popstackmark(&smark);
+
+		skip = evalskip;
+		if (skip) {
+			evalskip &= ~(SKIPFUNC | SKIPFUNCDEF);
+			break;
+		}
+	}
+
+	return status;
+}
+
+
+
+/*
+ * Read /etc/profile or .profile.  Return on error.
+ */
+
+STATIC void
+read_profile(const char *name)
+{
+	name = expandstr(name);
+	if (setinputfile(name, INPUT_PUSH_FILE | INPUT_NOFILE_OK) < 0)
+		return;
+
+	cmdloop(0);
+	popfile();
+}
+
+
+
+/*
+ * Read a file containing shell functions.
+ */
+
+void
+readcmdfile(char *name)
+{
+	setinputfile(name, INPUT_PUSH_FILE);
+	cmdloop(0);
+	popfile();
+}
+
+
+
+/*
+ * Take commands from a file.  To be compatible we should do a path
+ * search for the file, which is necessary to find sub-commands.
+ */
+
+
+STATIC char *
+find_dot_file(char *basename)
+{
+	char *fullname;
+	const char *path = pathval();
+	struct stat64 statb;
+	int len;
+
+	/* don't try this for absolute or relative paths */
+	if (strchr(basename, '/'))
+		return basename;
+
+	while ((len = padvance(&path, basename)) >= 0) {
+		fullname = stackblock();
+		if ((!pathopt || *pathopt == 'f') &&
+		    !stat64(fullname, &statb) && S_ISREG(statb.st_mode)) {
+			/* This will be freed by the caller. */
+			return stalloc(len);
+		}
+	}
+
+	/* not found in the PATH */
+	sh_error("%s: not found", basename);
+	/* NOTREACHED */
+}
+
+int
+dotcmd(int argc, char **argv)
+{
+	int status = 0;
+
+	nextopt(nullstr);
+	argv = argptr;
+
+	if (*argv) {
+		char *fullname;
+
+		fullname = find_dot_file(*argv);
+		setinputfile(fullname, INPUT_PUSH_FILE);
+		commandname = fullname;
+		status = cmdloop(0);
+		popfile();
+	}
+
+	return status;
+}
+
+
+int
+exitcmd(int argc, char **argv)
+{
+	if (stoppedjobs())
+		return 0;
+
+	if (argc > 1)
+		savestatus = number(argv[1]);
+
+	exraise(EXEXIT);
+	/* NOTREACHED */
+}
+
+#ifdef mkinit
+INCLUDE "error.h"
+
+FORKRESET {
+	handler = &main_handler;
+}
+#endif
diff --git a/src/main.h b/src/main.h
new file mode 100644
index 00000000..19e49835
--- /dev/null
+++ b/src/main.h
@@ -0,0 +1,54 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)main.h	8.2 (Berkeley) 5/4/95
+ */
+
+#include <errno.h>
+
+/* pid of main shell */
+extern int rootpid;
+/* shell level: 0 for the main shell, 1 for its children, and so on */
+extern int shlvl;
+#define rootshell (!shlvl)
+
+#ifdef __GLIBC__
+/* glibc sucks */
+extern int *dash_errno;
+#undef errno
+#define errno (*dash_errno)
+#endif
+
+void readcmdfile(char *);
+int dotcmd(int, char **);
+int exitcmd(int, char **);
diff --git a/src/memalloc.c b/src/memalloc.c
new file mode 100644
index 00000000..60637da1
--- /dev/null
+++ b/src/memalloc.c
@@ -0,0 +1,300 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "shell.h"
+#include "output.h"
+#include "memalloc.h"
+#include "error.h"
+#include "machdep.h"
+#include "mystring.h"
+#include "system.h"
+
+/*
+ * Like malloc, but returns an error when out of space.
+ */
+
+pointer
+ckmalloc(size_t nbytes)
+{
+	pointer p;
+
+	p = malloc(nbytes);
+	if (p == NULL)
+		sh_error("Out of space");
+	return p;
+}
+
+
+/*
+ * Same for realloc.
+ */
+
+pointer
+ckrealloc(pointer p, size_t nbytes)
+{
+	p = realloc(p, nbytes);
+	if (p == NULL)
+		sh_error("Out of space");
+	return p;
+}
+
+
+/*
+ * Make a copy of a string in safe storage.
+ */
+
+char *
+savestr(const char *s)
+{
+	char *p = strdup(s);
+	if (!p)
+		sh_error("Out of space");
+	return p;
+}
+
+
+/*
+ * Parse trees for commands are allocated in lifo order, so we use a stack
+ * to make this more efficient, and also to avoid all sorts of exception
+ * handling code to handle interrupts in the middle of a parse.
+ *
+ * The size 504 was chosen because the Ultrix malloc handles that size
+ * well.
+ */
+
+/* minimum size of a block */
+#define MINSIZE SHELL_ALIGN(504)
+
+struct stack_block {
+	struct stack_block *prev;
+	char space[MINSIZE];
+};
+
+struct stack_block stackbase;
+struct stack_block *stackp = &stackbase;
+char *stacknxt = stackbase.space;
+size_t stacknleft = MINSIZE;
+char *sstrend = stackbase.space + MINSIZE;
+
+pointer
+stalloc(size_t nbytes)
+{
+	char *p;
+	size_t aligned;
+
+	aligned = SHELL_ALIGN(nbytes);
+	if (aligned > stacknleft) {
+		size_t len;
+		size_t blocksize;
+		struct stack_block *sp;
+
+		blocksize = aligned;
+		if (blocksize < MINSIZE)
+			blocksize = MINSIZE;
+		len = sizeof(struct stack_block) - MINSIZE + blocksize;
+		if (len < blocksize)
+			sh_error("Out of space");
+		INTOFF;
+		sp = ckmalloc(len);
+		sp->prev = stackp;
+		stacknxt = sp->space;
+		stacknleft = blocksize;
+		sstrend = stacknxt + blocksize;
+		stackp = sp;
+		INTON;
+	}
+	p = stacknxt;
+	stacknxt += aligned;
+	stacknleft -= aligned;
+	return p;
+}
+
+
+void
+stunalloc(pointer p)
+{
+#ifdef DEBUG
+	if (!p || (stacknxt < (char *)p) || ((char *)p < stackp->space)) {
+		write(2, "stunalloc\n", 10);
+		abort();
+	}
+#endif
+	stacknleft += stacknxt - (char *)p;
+	stacknxt = p;
+}
+
+
+
+void pushstackmark(struct stackmark *mark, size_t len)
+{
+	mark->stackp = stackp;
+	mark->stacknxt = stacknxt;
+	mark->stacknleft = stacknleft;
+	grabstackblock(len);
+}
+
+void setstackmark(struct stackmark *mark)
+{
+	pushstackmark(mark, stacknxt == stackp->space && stackp != &stackbase);
+}
+
+
+void
+popstackmark(struct stackmark *mark)
+{
+	struct stack_block *sp;
+
+	INTOFF;
+	while (stackp != mark->stackp) {
+		sp = stackp;
+		stackp = sp->prev;
+		ckfree(sp);
+	}
+	stacknxt = mark->stacknxt;
+	stacknleft = mark->stacknleft;
+	sstrend = mark->stacknxt + mark->stacknleft;
+	INTON;
+}
+
+
+/*
+ * When the parser reads in a string, it wants to stick the string on the
+ * stack and only adjust the stack pointer when it knows how big the
+ * string is.  Stackblock (defined in stack.h) returns a pointer to a block
+ * of space on top of the stack and stackblocklen returns the length of
+ * this block.  Growstackblock will grow this space by at least one byte,
+ * possibly moving it (like realloc).  Grabstackblock actually allocates the
+ * part of the block that has been used.
+ */
+
+static void growstackblock(size_t min)
+{
+	size_t newlen;
+
+	newlen = stacknleft * 2;
+	if (newlen < stacknleft)
+		sh_error("Out of space");
+	min = SHELL_ALIGN(min | 128);
+	if (newlen < min)
+		newlen += min;
+
+	if (stacknxt == stackp->space && stackp != &stackbase) {
+		struct stack_block *sp;
+		struct stack_block *prevstackp;
+		size_t grosslen;
+
+		INTOFF;
+		sp = stackp;
+		prevstackp = sp->prev;
+		grosslen = newlen + sizeof(struct stack_block) - MINSIZE;
+		sp = ckrealloc((pointer)sp, grosslen);
+		sp->prev = prevstackp;
+		stackp = sp;
+		stacknxt = sp->space;
+		stacknleft = newlen;
+		sstrend = sp->space + newlen;
+		INTON;
+	} else {
+		char *oldspace = stacknxt;
+		int oldlen = stacknleft;
+		char *p = stalloc(newlen);
+
+		/* free the space we just allocated */
+		stacknxt = memcpy(p, oldspace, oldlen);
+		stacknleft += newlen;
+	}
+}
+
+/*
+ * The following routines are somewhat easier to use than the above.
+ * The user declares a variable of type STACKSTR, which may be declared
+ * to be a register.  The macro STARTSTACKSTR initializes things.  Then
+ * the user uses the macro STPUTC to add characters to the string.  In
+ * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is
+ * grown as necessary.  When the user is done, she can just leave the
+ * string there and refer to it using stackblock().  Or she can allocate
+ * the space for it using grabstackstr().  If it is necessary to allow
+ * someone else to use the stack temporarily and then continue to grow
+ * the string, the user should use grabstack to allocate the space, and
+ * then call ungrabstr(p) to return to the previous mode of operation.
+ *
+ * USTPUTC is like STPUTC except that it doesn't check for overflow.
+ * CHECKSTACKSPACE can be called before USTPUTC to ensure that there
+ * is space for at least one character.
+ */
+
+void *
+growstackstr(void)
+{
+	size_t len = stackblocksize();
+
+	growstackblock(0);
+	return stackblock() + len;
+}
+
+char *growstackto(size_t len)
+{
+	if (stackblocksize() < len)
+		growstackblock(len);
+	return stackblock();
+}
+
+/*
+ * Called from CHECKSTRSPACE.
+ */
+
+char *
+makestrspace(size_t newlen, char *p)
+{
+	size_t len = p - stacknxt;
+
+	return growstackto(len + newlen) + len;
+}
+
+char *
+stnputs(const char *s, size_t n, char *p)
+{
+	p = makestrspace(n, p);
+	p = mempcpy(p, s, n);
+	return p;
+}
+
+char *
+stputs(const char *s, char *p)
+{
+	return stnputs(s, strlen(s), p);
+}
diff --git a/src/memalloc.h b/src/memalloc.h
new file mode 100644
index 00000000..b9adf764
--- /dev/null
+++ b/src/memalloc.h
@@ -0,0 +1,101 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)memalloc.h	8.2 (Berkeley) 5/4/95
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+
+struct stackmark {
+	struct stack_block *stackp;
+	char *stacknxt;
+	size_t stacknleft;
+};
+
+
+extern char *stacknxt;
+extern size_t stacknleft;
+extern char *sstrend;
+
+pointer ckmalloc(size_t);
+pointer ckrealloc(pointer, size_t);
+char *savestr(const char *);
+pointer stalloc(size_t);
+void stunalloc(pointer);
+void pushstackmark(struct stackmark *mark, size_t len);
+void setstackmark(struct stackmark *);
+void popstackmark(struct stackmark *);
+void *growstackstr(void);
+char *growstackto(size_t len);
+char *makestrspace(size_t, char *);
+char *stnputs(const char *, size_t, char *);
+char *stputs(const char *, char *);
+
+
+static inline void grabstackblock(size_t len)
+{
+	stalloc(len);
+}
+
+static inline char *_STPUTC(int c, char *p) {
+	if (p == sstrend)
+		p = growstackstr();
+	*p++ = c;
+	return p;
+}
+
+#define stackblock() ((void *)stacknxt)
+#define stackblocksize() stacknleft
+#define STARTSTACKSTR(p) ((p) = stackblock())
+#define STPUTC(c, p) ((p) = _STPUTC((c), (p)))
+#define CHECKSTRSPACE(n, p) \
+	({ \
+		char *q = (p); \
+		size_t l = (n); \
+		size_t m = sstrend - q; \
+		if (l > m) \
+			(p) = makestrspace(l, q); \
+		0; \
+	})
+#define USTPUTC(c, p)	(*p++ = (c))
+#define STACKSTRNUL(p)	((p) == sstrend? (p = growstackstr(), *p = '\0') : (*p = '\0'))
+#define STUNPUTC(p)	(--p)
+#define STTOPC(p)	p[-1]
+#define STADJUST(amount, p)	(p += (amount))
+
+#define grabstackstr(p)	stalloc((char *)(p) - (char *)stackblock())
+#define ungrabstackstr(s, p) stunalloc((s))
+#define stackstrend() ((void *)sstrend)
+
+#define ckfree(p)	free((pointer)(p))
diff --git a/src/miscbltin.c b/src/miscbltin.c
new file mode 100644
index 00000000..5ccbbcb8
--- /dev/null
+++ b/src/miscbltin.c
@@ -0,0 +1,506 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Miscelaneous builtins.
+ */
+
+#include <sys/types.h>		/* quad_t */
+#include <sys/param.h>		/* BSD4_4 */
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <inttypes.h>
+
+#include "shell.h"
+#include "options.h"
+#include "var.h"
+#include "output.h"
+#include "memalloc.h"
+#include "error.h"
+#include "miscbltin.h"
+#include "mystring.h"
+#include "main.h"
+#include "expand.h"
+#include "parser.h"
+#include "trap.h"
+
+#undef rflag
+
+
+/** handle one line of the read command.
+ *  more fields than variables -> remainder shall be part of last variable.
+ *  less fields than variables -> remaining variables unset.
+ *
+ *  @param line complete line of input
+ *  @param ac argument count
+ *  @param ap argument (variable) list
+ *  @param len length of line including trailing '\0'
+ */
+static void
+readcmd_handle_line(char *s, int ac, char **ap)
+{
+	struct arglist arglist;
+	struct strlist *sl;
+
+	s = grabstackstr(s);
+
+	arglist.lastp = &arglist.list;
+	
+	ifsbreakup(s, ac, &arglist);
+	*arglist.lastp = NULL;
+	ifsfree();
+
+	sl = arglist.list;
+
+	do {
+		if (!sl) {
+			/* nullify remaining arguments */
+			do {
+				setvar(*ap, nullstr, 0);
+			} while (*++ap);
+
+			return;
+		}
+
+		/* set variable to field */
+		rmescapes(sl->text);
+		setvar(*ap, sl->text, 0);
+		sl = sl->next;
+	} while (*++ap);
+}
+
+/*
+ * The read builtin.  The -e option causes backslashes to escape the
+ * following character. The -p option followed by an argument prompts
+ * with the argument.
+ *
+ * This uses unbuffered input, which may be avoidable in some cases.
+ */
+
+int
+readcmd(int argc, char **argv)
+{
+	char **ap;
+	char c;
+	int rflag;
+	char *prompt;
+	char *p;
+	int startloc;
+	int newloc;
+	int status;
+	int i;
+
+	rflag = 0;
+	prompt = NULL;
+	while ((i = nextopt("p:r")) != '\0') {
+		if (i == 'p')
+			prompt = optionarg;
+		else
+			rflag = 1;
+	}
+	if (prompt && isatty(0)) {
+		out2str(prompt);
+#ifdef FLUSHERR
+		flushall();
+#endif
+	}
+	if (*(ap = argptr) == NULL)
+		sh_error("arg count");
+
+	status = 0;
+	STARTSTACKSTR(p);
+
+	goto start;
+
+	for (;;) {
+		switch (read(0, &c, 1)) {
+		case 1:
+			break;
+		default:
+			if (errno == EINTR && !pending_sig)
+				continue;
+				/* fall through */
+		case 0:
+			status = 1;
+			goto out;
+		}
+		if (c == '\0')
+			continue;
+		if (newloc >= startloc) {
+			if (c == '\n')
+				goto resetbs;
+			goto put;
+		}
+		if (!rflag && c == '\\') {
+			newloc = p - (char *)stackblock();
+			continue;
+		}
+		if (c == '\n')
+			break;
+put:
+		CHECKSTRSPACE(2, p);
+		if (strchr(qchars, c))
+			USTPUTC(CTLESC, p);
+		USTPUTC(c, p);
+
+		if (newloc >= startloc) {
+resetbs:
+			recordregion(startloc, newloc, 0);
+start:
+			startloc = p - (char *)stackblock();
+			newloc = startloc - 1;
+		}
+	}
+out:
+	recordregion(startloc, p - (char *)stackblock(), 0);
+	STACKSTRNUL(p);
+	readcmd_handle_line(p + 1, argc - (ap - argv), ap);
+	return status;
+}
+
+
+
+/*
+ * umask builtin
+ *
+ * This code was ripped from pdksh 5.2.14 and hacked for use with
+ * dash by Herbert Xu.
+ *
+ * Public domain.
+ */
+
+int
+umaskcmd(int argc, char **argv)
+{
+	char *ap;
+	int mask;
+	int i;
+	int symbolic_mode = 0;
+
+	while ((i = nextopt("S")) != '\0') {
+		symbolic_mode = 1;
+	}
+
+	INTOFF;
+	mask = umask(0);
+	umask(mask);
+	INTON;
+
+	if ((ap = *argptr) == NULL) {
+		if (symbolic_mode) {
+			char buf[18];
+			int j;
+
+			mask = ~mask;
+			ap = buf;
+			for (i = 0; i < 3; i++) {
+				*ap++ = "ugo"[i];
+				*ap++ = '=';
+				for (j = 0; j < 3; j++)
+					if (mask & (1 << (8 - (3*i + j))))
+						*ap++ = "rwx"[j];
+				*ap++ = ',';
+			}
+			ap[-1] = '\0';
+			out1fmt("%s\n", buf);
+		} else {
+			out1fmt("%.4o\n", mask);
+		}
+	} else {
+		int new_mask;
+
+		if (isdigit((unsigned char) *ap)) {
+			new_mask = 0;
+			do {
+				if (*ap >= '8' || *ap < '0')
+					sh_error(illnum, *argptr);
+				new_mask = (new_mask << 3) + (*ap - '0');
+			} while (*++ap != '\0');
+		} else {
+			int positions, new_val;
+			char op;
+
+			mask = ~mask;
+			new_mask = mask;
+			positions = 0;
+			while (*ap) {
+				while (*ap && strchr("augo", *ap))
+					switch (*ap++) {
+					case 'a': positions |= 0111; break;
+					case 'u': positions |= 0100; break;
+					case 'g': positions |= 0010; break;
+					case 'o': positions |= 0001; break;
+					}
+				if (!positions)
+					positions = 0111; /* default is a */
+				if (!strchr("=+-", op = *ap))
+					break;
+				ap++;
+				new_val = 0;
+				while (*ap && strchr("rwxugoXs", *ap))
+					switch (*ap++) {
+					case 'r': new_val |= 04; break;
+					case 'w': new_val |= 02; break;
+					case 'x': new_val |= 01; break;
+					case 'u': new_val |= mask >> 6;
+						  break;
+					case 'g': new_val |= mask >> 3;
+						  break;
+					case 'o': new_val |= mask >> 0;
+						  break;
+					case 'X': if (mask & 0111)
+							new_val |= 01;
+						  break;
+					case 's': /* ignored */
+						  break;
+					}
+				new_val = (new_val & 07) * positions;
+				switch (op) {
+				case '-':
+					new_mask &= ~new_val;
+					break;
+				case '=':
+					new_mask = new_val
+					    | (new_mask & ~(positions * 07));
+					break;
+				case '+':
+					new_mask |= new_val;
+				}
+				if (*ap == ',') {
+					positions = 0;
+					ap++;
+				} else if (!strchr("=+-", *ap))
+					break;
+			}
+			if (*ap) {
+				sh_error("Illegal mode: %s", *argptr);
+				return 1;
+			}
+			new_mask = ~new_mask;
+		}
+		umask(new_mask);
+	}
+	return 0;
+}
+
+#ifdef HAVE_GETRLIMIT
+/*
+ * ulimit builtin
+ *
+ * This code, originally by Doug Gwyn, Doug Kingston, Eric Gisin, and
+ * Michael Rendell was ripped from pdksh 5.0.8 and hacked for use with
+ * ash by J.T. Conklin.
+ *
+ * Public domain.
+ */
+
+struct limits {
+	const char *name;
+	int	cmd;
+	int	factor;	/* multiply by to get rlim_{cur,max} values */
+	char	option;
+};
+
+static const struct limits limits[] = {
+#ifdef RLIMIT_CPU
+	{ "time(seconds)",		RLIMIT_CPU,	   1, 't' },
+#endif
+#ifdef RLIMIT_FSIZE
+	{ "file(blocks)",		RLIMIT_FSIZE,	 512, 'f' },
+#endif
+#ifdef RLIMIT_DATA
+	{ "data(kbytes)",		RLIMIT_DATA,	1024, 'd' },
+#endif
+#ifdef RLIMIT_STACK
+	{ "stack(kbytes)",		RLIMIT_STACK,	1024, 's' },
+#endif
+#ifdef RLIMIT_CORE
+	{ "coredump(blocks)",		RLIMIT_CORE,	 512, 'c' },
+#endif
+#ifdef RLIMIT_RSS
+	{ "memory(kbytes)",		RLIMIT_RSS,	1024, 'm' },
+#endif
+#ifdef RLIMIT_MEMLOCK
+	{ "locked memory(kbytes)",	RLIMIT_MEMLOCK, 1024, 'l' },
+#endif
+#ifdef RLIMIT_NPROC
+	{ "process",			RLIMIT_NPROC,      1, 'p' },
+#endif
+#ifdef RLIMIT_NOFILE
+	{ "nofiles",			RLIMIT_NOFILE,     1, 'n' },
+#endif
+#ifdef RLIMIT_AS
+	{ "vmemory(kbytes)",		RLIMIT_AS,	1024, 'v' },
+#endif
+#ifdef RLIMIT_LOCKS
+	{ "locks",			RLIMIT_LOCKS,	   1, 'w' },
+#endif
+#ifdef RLIMIT_RTPRIO
+	{ "rtprio",			RLIMIT_RTPRIO,	   1, 'r' },
+#endif
+	{ (char *) 0,			0,		   0,  '\0' }
+};
+
+enum limtype { SOFT = 0x1, HARD = 0x2 };
+
+static void printlim(enum limtype how, const struct rlimit *limit,
+		     const struct limits *l)
+{
+	rlim_t val;
+
+	val = limit->rlim_max;
+	if (how & SOFT)
+		val = limit->rlim_cur;
+
+	if (val == RLIM_INFINITY)
+		out1fmt("unlimited\n");
+	else {
+		val /= l->factor;
+		out1fmt("%" PRIdMAX "\n", (intmax_t) val);
+	}
+}
+
+int
+ulimitcmd(int argc, char **argv)
+{
+	int	c;
+	rlim_t val = 0;
+	enum limtype how = SOFT | HARD;
+	const struct limits	*l;
+	int		set, all = 0;
+	int		optc, what;
+	struct rlimit	limit;
+
+	what = 'f';
+	while ((optc = nextopt("HSa"
+#ifdef RLIMIT_CPU
+			       "t"
+#endif
+#ifdef RLIMIT_FSIZE
+			       "f"
+#endif
+#ifdef RLIMIT_DATA
+			       "d"
+#endif
+#ifdef RLIMIT_STACK
+			       "s"
+#endif
+#ifdef RLIMIT_CORE
+			       "c"
+#endif
+#ifdef RLIMIT_RSS
+			       "m"
+#endif
+#ifdef RLIMIT_MEMLOCK
+			       "l"
+#endif
+#ifdef RLIMIT_NPROC
+			       "p"
+#endif
+#ifdef RLIMIT_NOFILE
+			       "n"
+#endif
+#ifdef RLIMIT_AS
+			       "v"
+#endif
+#ifdef RLIMIT_LOCKS
+			       "w"
+#endif
+	)) != '\0')
+		switch (optc) {
+		case 'H':
+			how = HARD;
+			break;
+		case 'S':
+			how = SOFT;
+			break;
+		case 'a':
+			all = 1;
+			break;
+		default:
+			what = optc;
+		}
+
+	for (l = limits; l->option != what; l++)
+		;
+
+	set = *argptr ? 1 : 0;
+	if (set) {
+		char *p = *argptr;
+
+		if (all || argptr[1])
+			sh_error("too many arguments");
+		if (strcmp(p, "unlimited") == 0)
+			val = RLIM_INFINITY;
+		else {
+			val = (rlim_t) 0;
+
+			while ((c = *p++) >= '0' && c <= '9')
+			{
+				val = (val * 10) + (long)(c - '0');
+				if (val < (rlim_t) 0)
+					break;
+			}
+			if (c)
+				sh_error("bad number");
+			val *= l->factor;
+		}
+	}
+	if (all) {
+		for (l = limits; l->name; l++) {
+			getrlimit(l->cmd, &limit);
+			out1fmt("%-20s ", l->name);
+			printlim(how, &limit, l);
+		}
+		return 0;
+	}
+
+	getrlimit(l->cmd, &limit);
+	if (set) {
+		if (how & HARD)
+			limit.rlim_max = val;
+		if (how & SOFT)
+			limit.rlim_cur = val;
+		if (setrlimit(l->cmd, &limit) < 0)
+			sh_error("error setting limit (%s)", strerror(errno));
+	} else {
+		printlim(how, &limit, l);
+	}
+	return 0;
+}
+#endif
diff --git a/src/miscbltin.h b/src/miscbltin.h
new file mode 100644
index 00000000..dd9a8d1c
--- /dev/null
+++ b/src/miscbltin.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 1997 Christos Zoulas.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+int readcmd(int, char **);
+int umaskcmd(int, char **);
+int ulimitcmd(int, char **);
diff --git a/src/mkbuiltins b/src/mkbuiltins
new file mode 100644
index 00000000..f1f25932
--- /dev/null
+++ b/src/mkbuiltins
@@ -0,0 +1,120 @@
+#!/bin/sh -
+#	$NetBSD: mkbuiltins,v 1.17 2002/11/24 22:35:41 christos Exp $
+#
+# Copyright (c) 1991, 1993
+#	The Regents of the University of California.  All rights reserved.
+# Copyright (c) 1997-2005
+#	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+#
+# This code is derived from software contributed to Berkeley by
+# Kenneth Almquist.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+#	@(#)mkbuiltins	8.2 (Berkeley) 5/4/95
+
+tempfile=mktemp
+if ! type tempfile > /dev/null 2>&1 && ! type mktemp > /dev/null 2>&1; then
+	_my_tempfile()
+	{
+		local index=0
+		while test -f "${TMPDIR:-/tmp}/builtin.$$.$index"; do
+			index=`expr $index + 1`
+		done
+
+		touch "${TMPDIR:-/tmp}/builtin.$$.$index"
+		echo "${TMPDIR:-/tmp}/builtin.$$.$index"
+	}
+
+	tempfile="_my_tempfile"
+elif ! type tempfile > /dev/null 2>&1; then
+	tempfile="mktemp ${TMPDIR:-/tmp}/builtin.XXXXXX"
+fi
+
+trap 'rm -f $temp $temp2' EXIT
+temp=$($tempfile)
+temp2=$($tempfile)
+
+builtins=$1
+
+exec > builtins.c
+cat <<\!
+/*
+ * This file was generated by the mkbuiltins program.
+ */
+
+#include "shell.h"
+#include "builtins.h"
+
+!
+< $builtins sed '/^#/d; /^ *$/d' > $temp
+awk '{	printf "int %s(int, char **);\n", $1}' $temp
+echo '
+const struct builtincmd builtincmd[] = {'
+awk '{	for (i = 2 ; i <= NF ; i++) {
+		line = $i "\t" $1
+		if ($i ~ /^-/)
+			line = $(++i) "\t" line
+		print line
+	}}' $temp | LC_ALL= LC_COLLATE=C sort -k 1,1 | tee $temp2 | awk '{
+		opt = ""
+		if (NF > 2) {
+			opt = substr($2, 2)
+			$2 = $3
+		}
+		mask = 0
+		cmd = $2
+		if (opt ~ /n/) { cmd = "NULL" }
+		if (opt ~ /s/) { mask += 1 }
+		if (opt ~ /[su]/) { mask += 2 }
+		if (opt ~ /a/) { mask += 4 }
+		printf "\t{ \"%s\", %s, %d },\n", $1, cmd, mask
+	}'
+echo '};'
+
+exec > builtins.h
+cat <<\!
+/*
+ * This file was generated by the mkbuiltins program.
+ */
+
+!
+sed 's/	-[a-z]*//' $temp2 | nl -ba -v0 |
+	LC_ALL= LC_COLLATE=C sort -u -k 3,3 |
+	tr abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ |
+	awk '{	printf "#define %s (builtincmd + %d)\n", $3, $1}'
+printf '\n#define NUMBUILTINS %d\n' $(wc -l < $temp2)
+echo '
+#define BUILTIN_SPECIAL 0x1
+#define BUILTIN_REGULAR 0x2
+#define BUILTIN_ASSIGN 0x4
+
+struct builtincmd {
+	const char *name;
+	int (*builtin)(int, char **);
+	unsigned flags;
+};
+
+extern const struct builtincmd builtincmd[];'
diff --git a/src/mkinit.c b/src/mkinit.c
new file mode 100644
index 00000000..9025862e
--- /dev/null
+++ b/src/mkinit.c
@@ -0,0 +1,493 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * This program scans all the source files for code to handle various
+ * special events and combines this code into one file.  This (allegedly)
+ * improves the structure of the program since there is no need for
+ * anyone outside of a module to know that that module performs special
+ * operations on particular events.
+ *
+ * Usage:  mkinit sourcefile...
+ */
+
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+
+/*
+ * OUTFILE is the name of the output file.  Output is initially written
+ * to the file OUTTEMP, which is then moved to OUTFILE.
+ */
+
+#define OUTFILE "init.c"
+#define OUTTEMP "init.c.new"
+
+
+/*
+ * A text structure is basicly just a string that grows as more characters
+ * are added onto the end of it.  It is implemented as a linked list of
+ * blocks of characters.  The routines addstr and addchar append a string
+ * or a single character, respectively, to a text structure.  Writetext
+ * writes the contents of a text structure to a file.
+ */
+
+#define BLOCKSIZE 512
+
+struct text {
+	char *nextc;
+	int nleft;
+	struct block *start;
+	struct block *last;
+};
+
+struct block {
+	struct block *next;
+	char text[BLOCKSIZE];
+};
+
+
+/*
+ * There is one event structure for each event that mkinit handles.
+ */
+
+struct event {
+	char *name;		/* name of event (e.g. INIT) */
+	char *routine;		/* name of routine called on event */
+	char *comment;		/* comment describing routine */
+	struct text code;	/* code for handling event */
+};
+
+
+char writer[] = "\
+/*\n\
+ * This file was generated by the mkinit program.\n\
+ */\n\
+\n";
+
+char init[] = "\
+/*\n\
+ * Initialization code.\n\
+ */\n";
+
+char exitreset[] = "\
+/*\n\
+ * This routine is called when an error or an interrupt occurs in an\n\
+ * interactive shell and control is returned to the main command loop\n\
+ * but prior to exitshell. \n\
+ */\n";
+
+char forkreset[] = "\
+/*\n\
+ * This routine is called when we enter a subshell.\n\
+ */\n";
+
+char reset[] = "\
+/*\n\
+ * This routine is called when an error or an interrupt occurs in an\n\
+ * interactive shell and control is returned to the main command loop.\n\
+ */\n";
+
+
+struct event event[] = {
+	{"INIT", "init", init},
+	{"EXITRESET", "exitreset", exitreset},
+	{"FORKRESET", "forkreset", forkreset},
+	{"RESET", "reset", reset},
+	{NULL, NULL}
+};
+
+
+char *curfile;				/* current file */
+int linno;				/* current line */
+char *header_files[200];		/* list of header files */
+struct text defines;			/* #define statements */
+struct text decls;			/* declarations */
+int amiddecls;				/* for formatting */
+
+
+void readfile(char *);
+int match(char *, char *);
+int gooddefine(char *);
+void doevent(struct event *, FILE *, char *);
+void doinclude(char *);
+void dodecl(char *, FILE *);
+void output(void);
+void addstr(char *, struct text *);
+void addchar(int, struct text *);
+void writetext(struct text *, FILE *);
+FILE *ckfopen(char *, char *);
+void *ckmalloc(int);
+char *savestr(char *);
+static void error(char *);
+int main(int, char **);
+
+#define equal(s1, s2)	(strcmp(s1, s2) == 0)
+
+int
+main(int argc, char **argv)
+{
+	char **ap;
+
+	header_files[0] = "\"shell.h\"";
+	header_files[1] = "\"mystring.h\"";
+	header_files[2] = "\"init.h\"";
+	for (ap = argv + 1 ; *ap ; ap++)
+		readfile(*ap);
+	output();
+	rename(OUTTEMP, OUTFILE);
+	exit(0);
+	/* NOTREACHED */
+}
+
+
+/*
+ * Parse an input file.
+ */
+
+void
+readfile(char *fname)
+{
+	FILE *fp;
+	char line[1024];
+	struct event *ep;
+
+	fp = ckfopen(fname, "r");
+	curfile = fname;
+	linno = 0;
+	amiddecls = 0;
+	while (fgets(line, sizeof line, fp) != NULL) {
+		linno++;
+		for (ep = event ; ep->name ; ep++) {
+			if (line[0] == ep->name[0] && match(ep->name, line)) {
+				doevent(ep, fp, fname);
+				break;
+			}
+		}
+		if (line[0] == 'I' && match("INCLUDE", line))
+			doinclude(line);
+		if (line[0] == 'M' && match("MKINIT", line))
+			dodecl(line, fp);
+		if (line[0] == '#' && gooddefine(line)) {
+		        char *cp;
+			char line2[1024];
+			static const char undef[] = "#undef ";
+
+			strcpy(line2, line);
+			memcpy(line2, undef, sizeof(undef) - 1);
+			cp = line2 + sizeof(undef) - 1;
+			while(*cp && (*cp == ' ' || *cp == '\t'))
+			        cp++;
+			while(*cp && *cp != ' ' && *cp != '\t' && *cp != '\n')
+			        cp++;
+			*cp++ = '\n'; *cp = '\0';
+			addstr(line2, &defines);
+			addstr(line, &defines);
+		}
+	}
+	fclose(fp);
+}
+
+
+int
+match(char *name, char *line)
+{
+	char *p, *q;
+
+	p = name, q = line;
+	while (*p) {
+		if (*p++ != *q++)
+			return 0;
+	}
+	if (*q != '{' && *q != ' ' && *q != '\t' && *q != '\n')
+		return 0;
+	return 1;
+}
+
+
+int
+gooddefine(char *line)
+{
+	char *p;
+
+	if (! match("#define", line))
+		return 0;			/* not a define */
+	p = line + 7;
+	while (*p == ' ' || *p == '\t')
+		p++;
+	while (*p != ' ' && *p != '\t') {
+		if (*p == '(')
+			return 0;		/* macro definition */
+		p++;
+	}
+	while (*p != '\n' && *p != '\0')
+		p++;
+	if (p[-1] == '\\')
+		return 0;			/* multi-line definition */
+	return 1;
+}
+
+
+void
+doevent(struct event *ep, FILE *fp, char *fname)
+{
+	char line[1024];
+	int indent;
+	char *p;
+
+	sprintf(line, "\n      /* from %s: */\n", fname);
+	addstr(line, &ep->code);
+	addstr("      {\n", &ep->code);
+	for (;;) {
+		linno++;
+		if (fgets(line, sizeof line, fp) == NULL)
+			error("Unexpected EOF");
+		if (equal(line, "}\n"))
+			break;
+		indent = 6;
+		for (p = line ; *p == '\t' ; p++)
+			indent += 8;
+		for ( ; *p == ' ' ; p++)
+			indent++;
+		if (*p == '\n' || *p == '#')
+			indent = 0;
+		while (indent >= 8) {
+			addchar('\t', &ep->code);
+			indent -= 8;
+		}
+		while (indent > 0) {
+			addchar(' ', &ep->code);
+			indent--;
+		}
+		addstr(p, &ep->code);
+	}
+	addstr("      }\n", &ep->code);
+}
+
+
+void
+doinclude(char *line)
+{
+	char *p;
+	char *name;
+	char **pp;
+
+	for (p = line ; *p != '"' && *p != '<' && *p != '\0' ; p++);
+	if (*p == '\0')
+		error("Expecting '\"' or '<'");
+	name = p;
+	while (*p != ' ' && *p != '\t' && *p != '\n')
+		p++;
+	if (p[-1] != '"' && p[-1] != '>')
+		error("Missing terminator");
+	*p = '\0';
+
+	/* name now contains the name of the include file */
+	for (pp = header_files ; *pp && ! equal(*pp, name) ; pp++);
+	if (*pp == NULL)
+		*pp = savestr(name);
+}
+
+
+void
+dodecl(char *line1, FILE *fp)
+{
+	char line[1024];
+	char *p, *q;
+
+	if (strcmp(line1, "MKINIT\n") == 0) { /* start of struct/union decl */
+		addchar('\n', &decls);
+		do {
+			linno++;
+			if (fgets(line, sizeof line, fp) == NULL)
+				error("Unterminated structure declaration");
+			addstr(line, &decls);
+		} while (line[0] != '}');
+		amiddecls = 0;
+	} else {
+		if (! amiddecls)
+			addchar('\n', &decls);
+		q = NULL;
+		for (p = line1 + 6 ; *p && strchr("=/\n", *p) == NULL; p++)
+			continue;
+		if (*p == '=') {		/* eliminate initialization */
+			for (q = p ; *q && *q != ';' ; q++);
+			if (*q == '\0')
+				q = NULL;
+			else {
+				while (p[-1] == ' ')
+					p--;
+				*p = '\0';
+			}
+		}
+		addstr("extern", &decls);
+		addstr(line1 + 6, &decls);
+		if (q != NULL)
+			addstr(q, &decls);
+		amiddecls = 1;
+	}
+}
+
+
+
+/*
+ * Write the output to the file OUTTEMP.
+ */
+
+void
+output(void)
+{
+	FILE *fp;
+	char **pp;
+	struct event *ep;
+
+	fp = ckfopen(OUTTEMP, "w");
+	fputs(writer, fp);
+	for (pp = header_files ; *pp ; pp++)
+		fprintf(fp, "#include %s\n", *pp);
+	fputs("\n\n\n", fp);
+	writetext(&defines, fp);
+	fputs("\n\n", fp);
+	writetext(&decls, fp);
+	for (ep = event ; ep->name ; ep++) {
+		fputs("\n\n\n", fp);
+		fputs(ep->comment, fp);
+		fprintf(fp, "\nvoid\n%s() {\n", ep->routine);
+		writetext(&ep->code, fp);
+		fprintf(fp, "}\n");
+	}
+	fclose(fp);
+}
+
+
+/*
+ * A text structure is simply a block of text that is kept in memory.
+ * Addstr appends a string to the text struct, and addchar appends a single
+ * character.
+ */
+
+void
+addstr(char *s, struct text *text)
+{
+	while (*s) {
+		if (--text->nleft < 0)
+			addchar(*s++, text);
+		else
+			*text->nextc++ = *s++;
+	}
+}
+
+
+void
+addchar(int c, struct text *text)
+{
+	struct block *bp;
+
+	if (--text->nleft < 0) {
+		bp = ckmalloc(sizeof *bp);
+		if (text->start == NULL)
+			text->start = bp;
+		else
+			text->last->next = bp;
+		text->last = bp;
+		text->nextc = bp->text;
+		text->nleft = BLOCKSIZE - 1;
+	}
+	*text->nextc++ = c;
+}
+
+/*
+ * Write the contents of a text structure to a file.
+ */
+void
+writetext(struct text *text, FILE *fp)
+{
+	struct block *bp;
+
+	if (text->start != NULL) {
+		for (bp = text->start ; bp != text->last ; bp = bp->next) {
+			if ((fwrite(bp->text, sizeof (char), BLOCKSIZE, fp)) != BLOCKSIZE)
+				error("Can't write data\n");
+		}
+		if ((fwrite(bp->text, sizeof (char), BLOCKSIZE - text->nleft, fp)) != (BLOCKSIZE - text->nleft))
+			error("Can't write data\n");
+	}
+}
+
+FILE *
+ckfopen(char *file, char *mode)
+{
+	FILE *fp;
+
+	if ((fp = fopen(file, mode)) == NULL) {
+		fprintf(stderr, "Can't open %s\n", file);
+		exit(2);
+	}
+	return fp;
+}
+
+void *
+ckmalloc(int nbytes)
+{
+	char *p;
+
+	if ((p = malloc(nbytes)) == NULL)
+		error("Out of space");
+	return p;
+}
+
+char *
+savestr(char *s)
+{
+	char *p;
+
+	p = ckmalloc(strlen(s) + 1);
+	strcpy(p, s);
+	return p;
+}
+
+static void
+error(char *msg)
+{
+	if (curfile != NULL)
+		fprintf(stderr, "%s:%d: ", curfile, linno);
+	fprintf(stderr, "%s\n", msg);
+	exit(2);
+	/* NOTREACHED */
+}
diff --git a/src/mknodes.c b/src/mknodes.c
new file mode 100644
index 00000000..1903a605
--- /dev/null
+++ b/src/mknodes.c
@@ -0,0 +1,448 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * This program reads the nodetypes file and nodes.c.pat file.  It generates
+ * the files nodes.h and nodes.c.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+
+#define MAXTYPES 50		/* max number of node types */
+#define MAXFIELDS 20		/* max fields in a structure */
+#define BUFLEN 100		/* size of character buffers */
+
+/* field types */
+#define T_NODE 1		/* union node *field */
+#define T_NODELIST 2		/* struct nodelist *field */
+#define T_STRING 3
+#define T_INT 4			/* int field */
+#define T_OTHER 5		/* other */
+#define T_TEMP 6		/* don't copy this field */
+
+
+struct field {			/* a structure field */
+	char *name;		/* name of field */
+	int type;			/* type of field */
+	char *decl;		/* declaration of field */
+};
+
+
+struct str {			/* struct representing a node structure */
+	char *tag;		/* structure tag */
+	int nfields;		/* number of fields in the structure */
+	struct field field[MAXFIELDS];	/* the fields of the structure */
+	int done;			/* set if fully parsed */
+};
+
+
+static int ntypes;			/* number of node types */
+static char *nodename[MAXTYPES];	/* names of the nodes */
+static struct str *nodestr[MAXTYPES];	/* type of structure used by the node */
+static int nstr;			/* number of structures */
+static struct str str[MAXTYPES];	/* the structures */
+static struct str *curstr;		/* current structure */
+static FILE *infp;
+static char line[1024];
+static int linno;
+static char *linep;
+
+static void parsenode(void);
+static void parsefield(void);
+static void output(char *);
+static void outsizes(FILE *);
+static void outfunc(FILE *, int);
+static void indent(int, FILE *);
+static int nextfield(char *);
+static void skipbl(void);
+static int readline(void);
+static void error(const char *, ...);
+static char *savestr(const char *);
+int main(int, char **);
+
+
+int
+main(int argc, char **argv)
+{
+
+	/*
+	 * some versions of linux complain: initializer element is not
+	 * constant if this is done at compile time.
+	 */
+	infp = stdin;
+
+	if (argc != 3)
+		error("usage: mknodes file");
+	if ((infp = fopen(argv[1], "r")) == NULL)
+		error("Can't open %s", argv[1]);
+	while (readline()) {
+		if (line[0] == ' ' || line[0] == '\t')
+			parsefield();
+		else if (line[0] != '\0')
+			parsenode();
+	}
+	output(argv[2]);
+	exit(0);
+	/* NOTREACHED */
+}
+
+
+
+static void
+parsenode(void)
+{
+	char name[BUFLEN];
+	char tag[BUFLEN];
+	struct str *sp;
+
+	if (curstr && curstr->nfields > 0)
+		curstr->done = 1;
+	nextfield(name);
+	if (! nextfield(tag))
+		error("Tag expected");
+	if (*linep != '\0')
+		error("Garbage at end of line");
+	nodename[ntypes] = savestr(name);
+	for (sp = str ; sp < str + nstr ; sp++) {
+		if (strcmp(sp->tag, tag) == 0)
+			break;
+	}
+	if (sp >= str + nstr) {
+		sp->tag = savestr(tag);
+		sp->nfields = 0;
+		curstr = sp;
+		nstr++;
+	}
+	nodestr[ntypes] = sp;
+	ntypes++;
+}
+
+
+static void
+parsefield(void)
+{
+	char name[BUFLEN];
+	char type[BUFLEN];
+	char decl[2 * BUFLEN];
+	struct field *fp;
+
+	if (curstr == NULL || curstr->done)
+		error("No current structure to add field to");
+	if (! nextfield(name))
+		error("No field name");
+	if (! nextfield(type))
+		error("No field type");
+	fp = &curstr->field[curstr->nfields];
+	fp->name = savestr(name);
+	if (strcmp(type, "nodeptr") == 0) {
+		fp->type = T_NODE;
+		sprintf(decl, "union node *%s", name);
+	} else if (strcmp(type, "nodelist") == 0) {
+		fp->type = T_NODELIST;
+		sprintf(decl, "struct nodelist *%s", name);
+	} else if (strcmp(type, "string") == 0) {
+		fp->type = T_STRING;
+		sprintf(decl, "char *%s", name);
+	} else if (strcmp(type, "int") == 0) {
+		fp->type = T_INT;
+		sprintf(decl, "int %s", name);
+	} else if (strcmp(type, "other") == 0) {
+		fp->type = T_OTHER;
+	} else if (strcmp(type, "temp") == 0) {
+		fp->type = T_TEMP;
+	} else {
+		error("Unknown type %s", type);
+	}
+	if (fp->type == T_OTHER || fp->type == T_TEMP) {
+		skipbl();
+		fp->decl = savestr(linep);
+	} else {
+		if (*linep)
+			error("Garbage at end of line");
+		fp->decl = savestr(decl);
+	}
+	curstr->nfields++;
+}
+
+
+char writer[] = "\
+/*\n\
+ * This file was generated by the mknodes program.\n\
+ */\n\
+\n";
+
+static void
+output(char *file)
+{
+	FILE *hfile;
+	FILE *cfile;
+	FILE *patfile;
+	int i;
+	struct str *sp;
+	struct field *fp;
+	char *p;
+
+	if ((patfile = fopen(file, "r")) == NULL)
+		error("Can't open %s", file);
+	if ((hfile = fopen("nodes.h", "w")) == NULL)
+		error("Can't create nodes.h");
+	if ((cfile = fopen("nodes.c", "w")) == NULL)
+		error("Can't create nodes.c");
+	fputs(writer, hfile);
+	for (i = 0 ; i < ntypes ; i++)
+		fprintf(hfile, "#define %s %d\n", nodename[i], i);
+	fputs("\n\n\n", hfile);
+	for (sp = str ; sp < &str[nstr] ; sp++) {
+		fprintf(hfile, "struct %s {\n", sp->tag);
+		for (i = sp->nfields, fp = sp->field ; --i >= 0 ; fp++) {
+			fprintf(hfile, "      %s;\n", fp->decl);
+		}
+		fputs("};\n\n\n", hfile);
+	}
+	fputs("union node {\n", hfile);
+	fprintf(hfile, "      int type;\n");
+	for (sp = str ; sp < &str[nstr] ; sp++) {
+		fprintf(hfile, "      struct %s %s;\n", sp->tag, sp->tag);
+	}
+	fputs("};\n\n\n", hfile);
+	fputs("struct nodelist {\n", hfile);
+	fputs("\tstruct nodelist *next;\n", hfile);
+	fputs("\tunion node *n;\n", hfile);
+	fputs("};\n\n\n", hfile);
+	fputs("struct funcnode {\n", hfile);
+	fputs("\tint count;\n", hfile);
+	fputs("\tunion node n;\n", hfile);
+	fputs("};\n\n\n", hfile);
+	fputs("struct funcnode *copyfunc(union node *);\n", hfile);
+	fputs("void freefunc(struct funcnode *);\n", hfile);
+
+	fputs(writer, cfile);
+	while (fgets(line, sizeof line, patfile) != NULL) {
+		for (p = line ; *p == ' ' || *p == '\t' ; p++);
+		if (strcmp(p, "%SIZES\n") == 0)
+			outsizes(cfile);
+		else if (strcmp(p, "%CALCSIZE\n") == 0)
+			outfunc(cfile, 1);
+		else if (strcmp(p, "%COPY\n") == 0)
+			outfunc(cfile, 0);
+		else
+			fputs(line, cfile);
+	}
+}
+
+
+
+static void
+outsizes(FILE *cfile)
+{
+	int i;
+
+	fprintf(cfile, "static const short nodesize[%d] = {\n", ntypes);
+	for (i = 0 ; i < ntypes ; i++) {
+		fprintf(cfile, "      SHELL_ALIGN(sizeof (struct %s)),\n",
+		    nodestr[i]->tag);
+	}
+	fprintf(cfile, "};\n");
+}
+
+
+static void
+outfunc(FILE *cfile, int calcsize)
+{
+	struct str *sp;
+	struct field *fp;
+	int i;
+
+	fputs("      if (n == NULL)\n", cfile);
+	if (calcsize)
+		fputs("	    return;\n", cfile);
+	else
+		fputs("	    return NULL;\n", cfile);
+	if (calcsize)
+		fputs("      funcblocksize += nodesize[n->type];\n", cfile);
+	else {
+		fputs("      new = funcblock;\n", cfile);
+		fputs("      funcblock = (char *) funcblock + nodesize[n->type];\n", cfile);
+	}
+	fputs("      switch (n->type) {\n", cfile);
+	for (sp = str ; sp < &str[nstr] ; sp++) {
+		for (i = 0 ; i < ntypes ; i++) {
+			if (nodestr[i] == sp)
+				fprintf(cfile, "      case %s:\n", nodename[i]);
+		}
+		for (i = sp->nfields ; --i >= 1 ; ) {
+			fp = &sp->field[i];
+			switch (fp->type) {
+			case T_NODE:
+				if (calcsize) {
+					indent(12, cfile);
+					fprintf(cfile, "calcsize(n->%s.%s);\n",
+						sp->tag, fp->name);
+				} else {
+					indent(12, cfile);
+					fprintf(cfile, "new->%s.%s = copynode(n->%s.%s);\n",
+						sp->tag, fp->name, sp->tag, fp->name);
+				}
+				break;
+			case T_NODELIST:
+				if (calcsize) {
+					indent(12, cfile);
+					fprintf(cfile, "sizenodelist(n->%s.%s);\n",
+						sp->tag, fp->name);
+				} else {
+					indent(12, cfile);
+					fprintf(cfile, "new->%s.%s = copynodelist(n->%s.%s);\n",
+						sp->tag, fp->name, sp->tag, fp->name);
+				}
+				break;
+			case T_STRING:
+				if (calcsize) {
+					indent(12, cfile);
+					fprintf(cfile, "funcstringsize += strlen(n->%s.%s) + 1;\n",
+						sp->tag, fp->name);
+				} else {
+					indent(12, cfile);
+					fprintf(cfile, "new->%s.%s = nodesavestr(n->%s.%s);\n",
+						sp->tag, fp->name, sp->tag, fp->name);
+				}
+				break;
+			case T_INT:
+			case T_OTHER:
+				if (! calcsize) {
+					indent(12, cfile);
+					fprintf(cfile, "new->%s.%s = n->%s.%s;\n",
+						sp->tag, fp->name, sp->tag, fp->name);
+				}
+				break;
+			}
+		}
+		indent(12, cfile);
+		fputs("break;\n", cfile);
+	}
+	fputs("      };\n", cfile);
+	if (! calcsize)
+		fputs("      new->type = n->type;\n", cfile);
+}
+
+
+static void
+indent(int amount, FILE *fp)
+{
+	while (amount >= 8) {
+		putc('\t', fp);
+		amount -= 8;
+	}
+	while (--amount >= 0) {
+		putc(' ', fp);
+	}
+}
+
+
+static int
+nextfield(char *buf)
+{
+	char *p, *q;
+
+	p = linep;
+	while (*p == ' ' || *p == '\t')
+		p++;
+	q = buf;
+	while (*p != ' ' && *p != '\t' && *p != '\0')
+		*q++ = *p++;
+	*q = '\0';
+	linep = p;
+	return (q > buf);
+}
+
+
+static void
+skipbl(void)
+{
+	while (*linep == ' ' || *linep == '\t')
+		linep++;
+}
+
+
+static int
+readline(void)
+{
+	char *p;
+
+	if (fgets(line, 1024, infp) == NULL)
+		return 0;
+	for (p = line ; *p != '#' && *p != '\n' && *p != '\0' ; p++);
+	while (p > line && (p[-1] == ' ' || p[-1] == '\t'))
+		p--;
+	*p = '\0';
+	linep = line;
+	linno++;
+	if (p - line > BUFLEN)
+		error("Line too long");
+	return 1;
+}
+
+
+
+static void
+error(const char *msg, ...)
+{
+	va_list va;
+
+	va_start(va, msg);
+
+	(void) fprintf(stderr, "line %d: ", linno);
+	(void) vfprintf(stderr, msg, va);
+	(void) fputc('\n', stderr);
+
+	va_end(va);
+
+	exit(2);
+	/* NOTREACHED */
+}
+
+
+
+static char *
+savestr(const char *s)
+{
+	char *p;
+
+	if ((p = malloc(strlen(s) + 1)) == NULL)
+		error("Out of space");
+	(void) strcpy(p, s);
+	return p;
+}
diff --git a/src/mksignames.c b/src/mksignames.c
new file mode 100644
index 00000000..a832eab9
--- /dev/null
+++ b/src/mksignames.c
@@ -0,0 +1,417 @@
+/* signames.c -- Create and write `signames.c', which contains an array of
+   signal names. */
+
+/* Copyright (C) 1992 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash, the Bourne Again SHell.
+
+   Bash is free software; you can redistribute it and/or modify it under
+   the terms of the GNU General Public License as published by the Free
+   Software Foundation; either version 2, or (at your option) any later
+   version.
+
+   Bash is distributed in the hope that it will be useful, but WITHOUT ANY
+   WARRANTY; without even the implied warranty of MERCHANTABILITY or
+   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+   for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with Bash; see the file COPYING.  If not, write to the Free Software
+   Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <stdlib.h>
+
+#if !defined (NSIG)
+#  define NSIG 64
+#endif
+
+/*
+ * Special traps:
+ *	EXIT == 0
+ */
+#define LASTSIG NSIG-1
+
+char *signal_names[2 * NSIG + 3];
+
+#define signal_names_size (sizeof(signal_names)/sizeof(signal_names[0]))
+
+char *progname;
+
+/* AIX 4.3 defines SIGRTMIN and SIGRTMAX as 888 and 999 respectively.
+   I don't want to allocate so much unused space for the intervening signal
+   numbers, so we just punt if SIGRTMAX is past the bounds of the
+   signal_names array (handled in configure). */
+#if defined (SIGRTMAX) && defined (UNUSABLE_RT_SIGNALS)
+#  undef SIGRTMAX
+#  undef SIGRTMIN
+#endif
+
+#if defined (SIGRTMAX) || defined (SIGRTMIN)
+#  define RTLEN 14
+#  define RTLIM 256
+#endif
+
+void
+initialize_signames ()
+{
+  register int i;
+#if defined (SIGRTMAX) || defined (SIGRTMIN)
+  int rtmin, rtmax, rtcnt;
+#endif
+
+  for (i = 1; i < signal_names_size; i++)
+    signal_names[i] = (char *)NULL;
+
+  /* `signal' 0 is what we do on exit. */
+  signal_names[0] = "EXIT";
+
+  /* Place signal names which can be aliases for more common signal
+     names first.  This allows (for example) SIGABRT to overwrite SIGLOST. */
+
+  /* POSIX 1003.1b-1993 real time signals, but take care of incomplete
+     implementations. Acoording to the standard, both, SIGRTMIN and
+     SIGRTMAX must be defined, SIGRTMIN must be stricly less than
+     SIGRTMAX, and the difference must be at least 7, that is, there
+     must be at least eight distinct real time signals. */
+
+  /* The generated signal names are SIGRTMIN, SIGRTMIN+1, ...,
+     SIGRTMIN+x, SIGRTMAX-x, ..., SIGRTMAX-1, SIGRTMAX. If the number
+     of RT signals is odd, there is an extra SIGRTMIN+(x+1).
+     These names are the ones used by ksh and /usr/xpg4/bin/sh on SunOS5. */
+
+#if defined (SIGRTMIN)
+  rtmin = SIGRTMIN;
+  signal_names[rtmin] = "RTMIN";
+#endif
+
+#if defined (SIGRTMAX)
+  rtmax = SIGRTMAX;
+  signal_names[rtmax] = "RTMAX";
+#endif
+
+#if defined (SIGRTMAX) && defined (SIGRTMIN)
+  if (rtmax > rtmin)
+    {
+      rtcnt = (rtmax - rtmin - 1) / 2;
+      /* croak if there are too many RT signals */
+      if (rtcnt >= RTLIM/2)
+	{
+	  rtcnt = RTLIM/2-1;
+	  fprintf(stderr, "%s: error: more than %i real time signals, fix `%s'\n",
+		  progname, RTLIM, progname);
+	}
+
+      for (i = 1; i <= rtcnt; i++)
+	{
+	  signal_names[rtmin+i] = (char *)malloc(RTLEN);
+	  if (signal_names[rtmin+i])
+	    sprintf (signal_names[rtmin+i], "RTMIN+%d", i);
+	  signal_names[rtmax-i] = (char *)malloc(RTLEN);
+	  if (signal_names[rtmax-i])
+	    sprintf (signal_names[rtmax-i], "RTMAX-%d", i);
+	}
+
+      if (rtcnt < RTLIM/2-1 && rtcnt != (rtmax-rtmin)/2)
+	{
+	  /* Need an extra RTMIN signal */
+	  signal_names[rtmin+rtcnt+1] = (char *)malloc(RTLEN);
+	  if (signal_names[rtmin+rtcnt+1])
+	    sprintf (signal_names[rtmin+rtcnt+1], "RTMIN+%d", rtcnt+1);
+	}
+    }
+#endif /* SIGRTMIN && SIGRTMAX */
+
+/* AIX */
+#if defined (SIGLOST)	/* resource lost (eg, record-lock lost) */
+  signal_names[SIGLOST] = "LOST";
+#endif
+
+#if defined (SIGMSG)	/* HFT input data pending */
+  signal_names[SIGMSG] = "MSG";
+#endif
+
+#if defined (SIGDANGER)	/* system crash imminent */
+  signal_names[SIGDANGER] = "DANGER";
+#endif
+
+#if defined (SIGMIGRATE) /* migrate process to another CPU */
+  signal_names[SIGMIGRATE] = "MIGRATE";
+#endif
+
+#if defined (SIGPRE)	/* programming error */
+  signal_names[SIGPRE] = "PRE";
+#endif
+
+#if defined (SIGVIRT)	/* AIX virtual time alarm */
+  signal_names[SIGVIRT] = "VIRT";
+#endif
+
+#if defined (SIGALRM1)	/* m:n condition variables */
+  signal_names[SIGALRM1] = "ALRM1";
+#endif
+
+#if defined (SIGWAITING)	/* m:n scheduling */
+  signal_names[SIGWAITING] = "WAITING";
+#endif
+
+#if defined (SIGGRANT)	/* HFT monitor mode granted */
+  signal_names[SIGGRANT] = "GRANT";
+#endif
+
+#if defined (SIGKAP)	/* keep alive poll from native keyboard */
+  signal_names[SIGKAP] = "KAP";
+#endif
+
+#if defined (SIGRETRACT) /* HFT monitor mode retracted */
+  signal_names[SIGRETRACT] = "RETRACT";
+#endif
+
+#if defined (SIGSOUND)	/* HFT sound sequence has completed */
+  signal_names[SIGSOUND] = "SOUND";
+#endif
+
+#if defined (SIGSAK)	/* Secure Attention Key */
+  signal_names[SIGSAK] = "SAK";
+#endif
+
+/* SunOS5 */
+#if defined (SIGLWP)	/* special signal used by thread library */
+  signal_names[SIGLWP] = "LWP";
+#endif
+
+#if defined (SIGFREEZE)	/* special signal used by CPR */
+  signal_names[SIGFREEZE] = "FREEZE";
+#endif
+
+#if defined (SIGTHAW)	/* special signal used by CPR */
+  signal_names[SIGTHAW] = "THAW";
+#endif
+
+#if defined (SIGCANCEL)	/* thread cancellation signal used by libthread */
+  signal_names[SIGCANCEL] = "CANCEL";
+#endif
+
+/* HP-UX */
+#if defined (SIGDIL)	/* DIL signal (?) */
+  signal_names[SIGDIL] = "DIL";
+#endif
+
+/* System V */
+#if defined (SIGCLD)	/* Like SIGCHLD.  */
+  signal_names[SIGCLD] = "CLD";
+#endif
+
+#if defined (SIGPWR)	/* power state indication */
+  signal_names[SIGPWR] = "PWR";
+#endif
+
+#if defined (SIGPOLL)	/* Pollable event (for streams)  */
+  signal_names[SIGPOLL] = "POLL";
+#endif
+
+/* Unknown */
+#if defined (SIGWINDOW)
+  signal_names[SIGWINDOW] = "WINDOW";
+#endif
+
+/* Common */
+#if defined (SIGHUP)	/* hangup */
+  signal_names[SIGHUP] = "HUP";
+#endif
+
+#if defined (SIGINT)	/* interrupt */
+  signal_names[SIGINT] = "INT";
+#endif
+
+#if defined (SIGQUIT)	/* quit */
+  signal_names[SIGQUIT] = "QUIT";
+#endif
+
+#if defined (SIGILL)	/* illegal instruction (not reset when caught) */
+  signal_names[SIGILL] = "ILL";
+#endif
+
+#if defined (SIGTRAP)	/* trace trap (not reset when caught) */
+  signal_names[SIGTRAP] = "TRAP";
+#endif
+
+#if defined (SIGIOT)	/* IOT instruction */
+  signal_names[SIGIOT] = "IOT";
+#endif
+
+#if defined (SIGABRT)	/* Cause current process to dump core. */
+  signal_names[SIGABRT] = "ABRT";
+#endif
+
+#if defined (SIGEMT)	/* EMT instruction */
+  signal_names[SIGEMT] = "EMT";
+#endif
+
+#if defined (SIGFPE)	/* floating point exception */
+  signal_names[SIGFPE] = "FPE";
+#endif
+
+#if defined (SIGKILL)	/* kill (cannot be caught or ignored) */
+  signal_names[SIGKILL] = "KILL";
+#endif
+
+#if defined (SIGBUS)	/* bus error */
+  signal_names[SIGBUS] = "BUS";
+#endif
+
+#if defined (SIGSEGV)	/* segmentation violation */
+  signal_names[SIGSEGV] = "SEGV";
+#endif
+
+#if defined (SIGSYS)	/* bad argument to system call */
+  signal_names[SIGSYS] = "SYS";
+#endif
+
+#if defined (SIGPIPE)	/* write on a pipe with no one to read it */
+  signal_names[SIGPIPE] = "PIPE";
+#endif
+
+#if defined (SIGALRM)	/* alarm clock */
+  signal_names[SIGALRM] = "ALRM";
+#endif
+
+#if defined (SIGTERM)	/* software termination signal from kill */
+  signal_names[SIGTERM] = "TERM";
+#endif
+
+#if defined (SIGURG)	/* urgent condition on IO channel */
+  signal_names[SIGURG] = "URG";
+#endif
+
+#if defined (SIGSTOP)	/* sendable stop signal not from tty */
+  signal_names[SIGSTOP] = "STOP";
+#endif
+
+#if defined (SIGTSTP)	/* stop signal from tty */
+  signal_names[SIGTSTP] = "TSTP";
+#endif
+
+#if defined (SIGCONT)	/* continue a stopped process */
+  signal_names[SIGCONT] = "CONT";
+#endif
+
+#if defined (SIGCHLD)	/* to parent on child stop or exit */
+  signal_names[SIGCHLD] = "CHLD";
+#endif
+
+#if defined (SIGTTIN)	/* to readers pgrp upon background tty read */
+  signal_names[SIGTTIN] = "TTIN";
+#endif
+
+#if defined (SIGTTOU)	/* like TTIN for output if (tp->t_local&LTOSTOP) */
+  signal_names[SIGTTOU] = "TTOU";
+#endif
+
+#if defined (SIGIO)	/* input/output possible signal */
+  signal_names[SIGIO] = "IO";
+#endif
+
+#if defined (SIGXCPU)	/* exceeded CPU time limit */
+  signal_names[SIGXCPU] = "XCPU";
+#endif
+
+#if defined (SIGXFSZ)	/* exceeded file size limit */
+  signal_names[SIGXFSZ] = "XFSZ";
+#endif
+
+#if defined (SIGVTALRM)	/* virtual time alarm */
+  signal_names[SIGVTALRM] = "VTALRM";
+#endif
+
+#if defined (SIGPROF)	/* profiling time alarm */
+  signal_names[SIGPROF] = "PROF";
+#endif
+
+#if defined (SIGWINCH)	/* window changed */
+  signal_names[SIGWINCH] = "WINCH";
+#endif
+
+/* 4.4 BSD */
+#if defined (SIGINFO) && !defined (_SEQUENT_)	/* information request */
+  signal_names[SIGINFO] = "INFO";
+#endif
+
+#if defined (SIGUSR1)	/* user defined signal 1 */
+  signal_names[SIGUSR1] = "USR1";
+#endif
+
+#if defined (SIGUSR2)	/* user defined signal 2 */
+  signal_names[SIGUSR2] = "USR2";
+#endif
+
+#if defined (SIGKILLTHR)	/* BeOS: Kill Thread */
+  signal_names[SIGKILLTHR] = "KILLTHR";
+#endif
+
+  for (i = 0; i < NSIG; i++)
+    if (signal_names[i] == (char *)NULL)
+      {
+	signal_names[i] = (char *)malloc (18);
+	if (signal_names[i])
+	  sprintf (signal_names[i], "%d", i);
+      }
+}
+
+void
+write_signames (stream)
+     FILE *stream;
+{
+  register int i;
+
+  fprintf (stream, "/* This file was automatically created by %s.\n",
+	   progname);
+  fprintf (stream, "   Do not edit.  Edit support/mksignames.c instead. */\n\n");
+  fprintf (stream, "#include <signal.h>\n\n");
+  fprintf (stream,
+	   "/* A translation list so we can be polite to our users. */\n");
+  fprintf (stream, "const char *const signal_names[NSIG + 1] = {\n");
+
+  for (i = 0; i <= LASTSIG; i++)
+    fprintf (stream, "    \"%s\",\n", signal_names[i]);
+
+  fprintf (stream, "    (char *)0x0\n");
+  fprintf (stream, "};\n");
+}
+
+int
+main(int argc, char **argv)
+{
+  char *stream_name;
+  FILE *stream;
+
+  progname = argv[0];
+
+  if (argc == 1)
+    {
+      stream_name = "signames.c";
+    }
+  else if (argc == 2)
+    {
+      stream_name = argv[1];
+    }
+  else
+    {
+      fprintf (stderr, "Usage: %s [output-file]\n", progname);
+      exit (1);
+    }
+
+  stream = fopen (stream_name, "w");
+  if (!stream)
+    {
+      fprintf (stderr, "%s: %s: cannot open for writing\n",
+	       progname, stream_name);
+      exit (2);
+    }
+
+  initialize_signames ();
+  write_signames (stream);
+  exit (0);
+}
diff --git a/src/mksyntax.c b/src/mksyntax.c
new file mode 100644
index 00000000..a23c18ca
--- /dev/null
+++ b/src/mksyntax.c
@@ -0,0 +1,315 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * This program creates syntax.h and syntax.c.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include "parser.h"
+
+
+struct synclass {
+	char *name;
+	char *comment;
+};
+
+/* Syntax classes */
+struct synclass synclass[] = {
+	{ "CWORD",	"character is nothing special" },
+	{ "CNL",	"newline character" },
+	{ "CBACK",	"a backslash character" },
+	{ "CSQUOTE",	"single quote" },
+	{ "CDQUOTE",	"double quote" },
+	{ "CENDQUOTE",	"a terminating quote" },
+	{ "CBQUOTE",	"backwards single quote" },
+	{ "CVAR",	"a dollar sign" },
+	{ "CENDVAR",	"a '}' character" },
+	{ "CLP",	"a left paren in arithmetic" },
+	{ "CRP",	"a right paren in arithmetic" },
+	{ "CEOF",	"end of file" },
+	{ "CCTL",	"like CWORD, except it must be escaped" },
+	{ "CSPCL",	"these terminate a word" },
+	{ "CIGN",	"character should be ignored" },
+	{ NULL,		NULL }
+};
+
+
+/*
+ * Syntax classes for is_ functions.  Warning:  if you add new classes
+ * you may have to change the definition of the is_in_name macro.
+ */
+struct synclass is_entry[] = {
+	{ "ISDIGIT",	"a digit" },
+	{ "ISUPPER",	"an upper case letter" },
+	{ "ISLOWER",	"a lower case letter" },
+	{ "ISUNDER",	"an underscore" },
+	{ "ISSPECL",	"the name of a special parameter" },
+	{ NULL, 	NULL }
+};
+
+static char writer[] = "\
+/*\n\
+ * This file was generated by the mksyntax program.\n\
+ */\n\
+\n";
+
+
+static FILE *cfile;
+static FILE *hfile;
+static char *syntax[513];
+
+static void filltable(char *);
+static void init(void);
+static void add(char *, char *);
+static void print(char *);
+static void output_type_macros(void);
+int main(int, char **);
+
+int
+main(int argc, char **argv)
+{
+	int i;
+	char buf[80];
+	int pos;
+
+	/* Create output files */
+	if ((cfile = fopen("syntax.c", "w")) == NULL) {
+		perror("syntax.c");
+		exit(2);
+	}
+	if ((hfile = fopen("syntax.h", "w")) == NULL) {
+		perror("syntax.h");
+		exit(2);
+	}
+	fputs(writer, hfile);
+	fputs(writer, cfile);
+
+	fputs("#include <ctype.h>\n", hfile);
+	fputs("\n", hfile);
+	fputs("#ifdef CEOF\n", hfile);
+	fputs("#undef CEOF\n", hfile);
+	fputs("#endif\n", hfile);
+	fputs("\n", hfile);
+
+	/* Generate the #define statements in the header file */
+	fputs("/* Syntax classes */\n", hfile);
+	for (i = 0 ; synclass[i].name ; i++) {
+		sprintf(buf, "#define %s %d", synclass[i].name, i);
+		fputs(buf, hfile);
+		for (pos = strlen(buf) ; pos < 32 ; pos = (pos + 8) & ~07)
+			putc('\t', hfile);
+		fprintf(hfile, "/* %s */\n", synclass[i].comment);
+	}
+	putc('\n', hfile);
+	fputs("/* Syntax classes for is_ functions */\n", hfile);
+	for (i = 0 ; is_entry[i].name ; i++) {
+		sprintf(buf, "#define %s %#o", is_entry[i].name, 1 << i);
+		fputs(buf, hfile);
+		for (pos = strlen(buf) ; pos < 32 ; pos = (pos + 8) & ~07)
+			putc('\t', hfile);
+		fprintf(hfile, "/* %s */\n", is_entry[i].comment);
+	}
+	putc('\n', hfile);
+	fprintf(hfile, "#define SYNBASE %d\n", 130);
+	fprintf(hfile, "#define PEOF %d\n\n", -130);
+	fprintf(hfile, "#define PEOA %d\n\n", -129);
+	putc('\n', hfile);
+	fputs("#define BASESYNTAX (basesyntax + SYNBASE)\n", hfile);
+	fputs("#define DQSYNTAX (dqsyntax + SYNBASE)\n", hfile);
+	fputs("#define SQSYNTAX (sqsyntax + SYNBASE)\n", hfile);
+	fputs("#define ARISYNTAX (arisyntax + SYNBASE)\n", hfile);
+	putc('\n', hfile);
+	output_type_macros();		/* is_digit, etc. */
+	putc('\n', hfile);
+
+	/* Generate the syntax tables. */
+	fputs("#include \"shell.h\"\n", cfile);
+	fputs("#include \"syntax.h\"\n\n", cfile);
+	init();
+	fputs("/* syntax table used when not in quotes */\n", cfile);
+	add("\n", "CNL");
+	add("\\", "CBACK");
+	add("'", "CSQUOTE");
+	add("\"", "CDQUOTE");
+	add("`", "CBQUOTE");
+	add("$", "CVAR");
+	add("}", "CENDVAR");
+	add("<>();&| \t", "CSPCL");
+	syntax[1] = "CSPCL";
+	print("basesyntax");
+	init();
+	fputs("\n/* syntax table used when in double quotes */\n", cfile);
+	add("\n", "CNL");
+	add("\\", "CBACK");
+	add("\"", "CENDQUOTE");
+	add("`", "CBQUOTE");
+	add("$", "CVAR");
+	add("}", "CENDVAR");
+	/* ':/' for tilde expansion, '-' for [a\-x] pattern ranges */
+	add("!*?[=~:/-]", "CCTL");
+	print("dqsyntax");
+	init();
+	fputs("\n/* syntax table used when in single quotes */\n", cfile);
+	add("\n", "CNL");
+	add("'", "CENDQUOTE");
+	/* ':/' for tilde expansion, '-' for [a\-x] pattern ranges */
+	add("!*?[=~:/-]\\", "CCTL");
+	print("sqsyntax");
+	init();
+	fputs("\n/* syntax table used when in arithmetic */\n", cfile);
+	add("\n", "CNL");
+	add("\\", "CBACK");
+	add("`", "CBQUOTE");
+	add("$", "CVAR");
+	add("}", "CENDVAR");
+	add("(", "CLP");
+	add(")", "CRP");
+	print("arisyntax");
+	filltable("0");
+	fputs("\n/* character classification table */\n", cfile);
+	add("0123456789", "ISDIGIT");
+	add("abcdefghijklmnopqrstucvwxyz", "ISLOWER");
+	add("ABCDEFGHIJKLMNOPQRSTUCVWXYZ", "ISUPPER");
+	add("_", "ISUNDER");
+	add("#?$!-*@", "ISSPECL");
+	print("is_type");
+	exit(0);
+	/* NOTREACHED */
+}
+
+
+
+/*
+ * Clear the syntax table.
+ */
+
+static void
+filltable(char *dftval)
+{
+	int i;
+
+	for (i = 0 ; i < 258; i++)
+		syntax[i] = dftval;
+}
+
+
+/*
+ * Initialize the syntax table with default values.
+ */
+
+static void
+init(void)
+{
+	int ctl;
+
+	filltable("CWORD");
+	syntax[0] = "CEOF";
+	syntax[1] = "CIGN";
+	for (ctl = CTL_FIRST; ctl <= CTL_LAST; ctl++ )
+		syntax[130 + ctl] = "CCTL";
+}
+
+
+/*
+ * Add entries to the syntax table.
+ */
+
+static void
+add(char *p, char *type)
+{
+	while (*p)
+		syntax[(signed char)*p++ + 130] = type;
+}
+
+
+
+/*
+ * Output the syntax table.
+ */
+
+static void
+print(char *name)
+{
+	int i;
+	int col;
+
+	fprintf(hfile, "extern const char %s[];\n", name);
+	fprintf(cfile, "const char %s[] = {\n", name);
+	col = 0;
+	for (i = 0 ; i < 258; i++) {
+		if (i == 0) {
+			fputs("      ", cfile);
+		} else if ((i & 03) == 0) {
+			fputs(",\n      ", cfile);
+			col = 0;
+		} else {
+			putc(',', cfile);
+			while (++col < 9 * (i & 03))
+				putc(' ', cfile);
+		}
+		fputs(syntax[i], cfile);
+		col += strlen(syntax[i]);
+	}
+	fputs("\n};\n", cfile);
+}
+
+
+
+/*
+ * Output character classification macros (e.g. is_digit).  If digits are
+ * contiguous, we can test for them quickly.
+ */
+
+static char *macro[] = {
+	"#define is_digit(c)\t((unsigned)((c) - '0') <= 9)\n",
+	"#define is_alpha(c)\tisalpha((unsigned char)(c))\n",
+	"#define is_name(c)\t((c) == '_' || isalpha((unsigned char)(c)))\n",
+	"#define is_in_name(c)\t((c) == '_' || isalnum((unsigned char)(c)))\n",
+	"#define is_special(c)\t((is_type+SYNBASE)[(signed char)(c)] & (ISSPECL|ISDIGIT))\n",
+	NULL
+};
+
+static void
+output_type_macros(void)
+{
+	char **pp;
+
+	for (pp = macro ; *pp ; pp++)
+		fputs(*pp, hfile);
+	fputs("#define digit_val(c)\t((c) - '0')\n", hfile);
+}
diff --git a/src/mktokens b/src/mktokens
new file mode 100644
index 00000000..78055be8
--- /dev/null
+++ b/src/mktokens
@@ -0,0 +1,97 @@
+#!/bin/sh -
+# Copyright (c) 1991, 1993
+#	The Regents of the University of California.  All rights reserved.
+# Copyright (c) 1997-2005
+#	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+#
+# This code is derived from software contributed to Berkeley by
+# Kenneth Almquist.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+#	@(#)mktokens	8.1 (Berkeley) 5/31/93
+
+# The following is a list of tokens.  The second column is nonzero if the
+# token marks the end of a list.  The third column is the name to print in
+# error messages.
+
+: "${TMPDIR:=/tmp}"
+
+cat > "${TMPDIR}"/ka$$ <<\!
+TEOF	1	end of file
+TNL	0	newline
+TSEMI	0	";"
+TBACKGND 0	"&"
+TAND	0	"&&"
+TOR	0	"||"
+TPIPE	0	"|"
+TLP	0	"("
+TRP	1	")"
+TENDCASE 1	";;"
+TENDBQUOTE 1	"`"
+TREDIR	0	redirection
+TWORD	0	word
+TNOT	0	"!"
+TCASE	0	"case"
+TDO	1	"do"
+TDONE	1	"done"
+TELIF	1	"elif"
+TELSE	1	"else"
+TESAC	1	"esac"
+TFI	1	"fi"
+TFOR	0	"for"
+TIF	0	"if"
+TIN	0	"in"
+TTHEN	1	"then"
+TUNTIL	0	"until"
+TWHILE	0	"while"
+TBEGIN	0	"{"
+TEND	1	"}"
+!
+nl=`wc -l "${TMPDIR}"/ka$$`
+exec > token.h
+awk '{print "#define " $1 " " NR-1}' "${TMPDIR}"/ka$$
+
+exec > token_vars.h
+
+echo '
+/* Array indicating which tokens mark the end of a list */
+static const char tokendlist[] = {'
+awk '{print "\t" $2 ","}' "${TMPDIR}"/ka$$
+echo '};
+
+static const char *const tokname[] = {'
+sed -e 's/"/\\"/g' \
+    -e 's/[^	 ]*[	 ][	 ]*[^	 ]*[	 ][	 ]*\(.*\)/	"\1",/' \
+    "${TMPDIR}"/ka$$
+echo '};
+'
+sed 's/"//g' "${TMPDIR}"/ka$$ | awk '
+/TNOT/{print "#define KWDOFFSET " NR-1; print ""; 
+      print "static const char *const parsekwd[] = {"}
+/TNOT/,/neverfound/{if (last) print "	\"" last "\","; last = $3}
+END{print "	\"" last "\"\n};"}'
+
+rm "${TMPDIR}"/ka$$
diff --git a/src/myhistedit.h b/src/myhistedit.h
new file mode 100644
index 00000000..22e5c438
--- /dev/null
+++ b/src/myhistedit.h
@@ -0,0 +1,46 @@
+/*-
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)myhistedit.h	8.2 (Berkeley) 5/4/95
+ */
+
+#include <histedit.h>
+
+extern History *hist;
+extern EditLine *el;
+extern int displayhist;
+
+void histedit(void);
+void sethistsize(const char *);
+void setterm(const char *);
+int histcmd(int, char **);
+int not_fcnumber(char *);
+int str_to_event(const char *, int);
+
diff --git a/src/mystring.c b/src/mystring.c
new file mode 100644
index 00000000..de624b89
--- /dev/null
+++ b/src/mystring.c
@@ -0,0 +1,257 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * String functions.
+ *
+ *	equal(s1, s2)		Return true if strings are equal.
+ *	scopy(from, to)		Copy a string.
+ *	scopyn(from, to, n)	Like scopy, but checks for overflow.
+ *	number(s)		Convert a string of digits to an integer.
+ *	is_number(s)		Return true if s is a string of digits.
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include "shell.h"
+#include "syntax.h"
+#include "error.h"
+#include "mystring.h"
+#include "memalloc.h"
+#include "parser.h"
+#include "system.h"
+
+
+char nullstr[1];		/* zero length string */
+const char spcstr[] = " ";
+const char snlfmt[] = "%s\n";
+const char dolatstr[] = { CTLQUOTEMARK, CTLVAR, VSNORMAL, '@', '=',
+			  CTLQUOTEMARK, '\0' };
+const char qchars[] = { CTLESC, CTLQUOTEMARK, 0 };
+const char illnum[] = "Illegal number: %s";
+const char homestr[] = "HOME";
+
+/*
+ * equal - #defined in mystring.h
+ */
+
+/*
+ * scopy - #defined in mystring.h
+ */
+
+
+#if 0
+/*
+ * scopyn - copy a string from "from" to "to", truncating the string
+ *		if necessary.  "To" is always nul terminated, even if
+ *		truncation is performed.  "Size" is the size of "to".
+ */
+
+void
+scopyn(const char *from, char *to, int size)
+{
+
+	while (--size > 0) {
+		if ((*to++ = *from++) == '\0')
+			return;
+	}
+	*to = '\0';
+}
+#endif
+
+
+/*
+ * prefix -- see if pfx is a prefix of string.
+ */
+
+char *
+prefix(const char *string, const char *pfx)
+{
+	while (*pfx) {
+		if (*pfx++ != *string++)
+			return 0;
+	}
+	return (char *) string;
+}
+
+void badnum(const char *s)
+{
+	sh_error(illnum, s);
+}
+
+/*
+ * Convert a string into an integer of type intmax_t.  Alow trailing spaces.
+ */
+intmax_t atomax(const char *s, int base)
+{
+	char *p;
+	intmax_t r;
+
+	errno = 0;
+	r = strtoimax(s, &p, base);
+
+	if (errno == ERANGE)
+		badnum(s);
+
+	/*
+	 * Disallow completely blank strings in non-arithmetic (base != 0)
+	 * contexts.
+	 */
+	if (p == s && base)
+		badnum(s);
+
+	while (isspace((unsigned char)*p))
+	      p++;
+
+	if (*p)
+		badnum(s);
+
+	return r;
+}
+
+intmax_t atomax10(const char *s)
+{
+	return atomax(s, 10);
+}
+
+/*
+ * Convert a string of digits to an integer, printing an error message on
+ * failure.
+ */
+
+int
+number(const char *s)
+{
+	intmax_t n = atomax10(s);
+
+	if (n < 0 || n > INT_MAX)
+		badnum(s);
+
+	return n;
+}
+
+
+
+/*
+ * Check for a valid number.  This should be elsewhere.
+ */
+
+int
+is_number(const char *p)
+{
+	do {
+		if (! is_digit(*p))
+			return 0;
+	} while (*++p != '\0');
+	return 1;
+}
+
+
+/*
+ * Produce a possibly single quoted string suitable as input to the shell.
+ * The return string is allocated on the stack.
+ */
+
+char *
+single_quote(const char *s) {
+	char *p;
+
+	STARTSTACKSTR(p);
+
+	do {
+		char *q;
+		size_t len;
+
+		len = strchrnul(s, '\'') - s;
+
+		q = p = makestrspace(len + 3, p);
+
+		*q++ = '\'';
+		q = mempcpy(q, s, len);
+		*q++ = '\'';
+		s += len;
+
+		STADJUST(q - p, p);
+
+		len = strspn(s, "'");
+		if (!len)
+			break;
+
+		q = p = makestrspace(len + 3, p);
+
+		*q++ = '"';
+		q = mempcpy(q, s, len);
+		*q++ = '"';
+		s += len;
+
+		STADJUST(q - p, p);
+	} while (*s);
+
+	USTPUTC(0, p);
+
+	return stackblock();
+}
+
+/*
+ * Like strdup but works with the ash stack.
+ */
+
+char *
+sstrdup(const char *p)
+{
+	size_t len = strlen(p) + 1;
+	return memcpy(stalloc(len), p, len);
+}
+
+/*
+ * Wrapper around strcmp for qsort/bsearch/...
+ */
+int
+pstrcmp(const void *a, const void *b)
+{
+	return strcmp(*(const char *const *) a, *(const char *const *) b);
+}
+
+/*
+ * Find a string is in a sorted array.
+ */
+const char *const *
+findstring(const char *s, const char *const *array, size_t nmemb)
+{
+	return bsearch(&s, array, nmemb, sizeof(const char *), pstrcmp);
+}
diff --git a/src/mystring.h b/src/mystring.h
new file mode 100644
index 00000000..083ea98c
--- /dev/null
+++ b/src/mystring.h
@@ -0,0 +1,63 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)mystring.h	8.2 (Berkeley) 5/4/95
+ */
+
+#include <inttypes.h>
+#include <string.h>
+
+extern const char snlfmt[];
+extern const char spcstr[];
+extern const char dolatstr[];
+#define DOLATSTRLEN 6
+extern const char qchars[];
+extern const char illnum[];
+extern const char homestr[];
+
+#if 0
+void scopyn(const char *, char *, int);
+#endif
+char *prefix(const char *, const char *);
+void badnum(const char *s) __attribute__ ((noreturn));
+intmax_t atomax(const char *, int);
+intmax_t atomax10(const char *);
+int number(const char *);
+int is_number(const char *);
+char *single_quote(const char *);
+char *sstrdup(const char *);
+int pstrcmp(const void *, const void *);
+const char *const *findstring(const char *, const char *const *, size_t);
+
+#define equal(s1, s2)	(strcmp(s1, s2) == 0)
+#define scopy(s1, s2)	((void)strcpy(s2, s1))
diff --git a/src/nodes.c.pat b/src/nodes.c.pat
new file mode 100644
index 00000000..9125bc73
--- /dev/null
+++ b/src/nodes.c.pat
@@ -0,0 +1,166 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)nodes.c.pat	8.2 (Berkeley) 5/4/95
+ */
+
+#include <stdlib.h>
+/*
+ * Routine for dealing with parsed shell commands.
+ */
+
+#include "shell.h"
+#include "nodes.h"
+#include "memalloc.h"
+#include "machdep.h"
+#include "mystring.h"
+#include "system.h"
+
+
+int     funcblocksize;		/* size of structures in function */
+int     funcstringsize;		/* size of strings in node */
+pointer funcblock;		/* block to allocate function from */
+char   *funcstring;		/* block to allocate strings from */
+
+%SIZES
+
+
+STATIC void calcsize(union node *);
+STATIC void sizenodelist(struct nodelist *);
+STATIC union node *copynode(union node *);
+STATIC struct nodelist *copynodelist(struct nodelist *);
+STATIC char *nodesavestr(char *);
+
+
+
+/*
+ * Make a copy of a parse tree.
+ */
+
+struct funcnode *
+copyfunc(union node *n)
+{
+	struct funcnode *f;
+	size_t blocksize;
+
+	funcblocksize = offsetof(struct funcnode, n);
+	funcstringsize = 0;
+	calcsize(n);
+	blocksize = funcblocksize;
+	f = ckmalloc(blocksize + funcstringsize);
+	funcblock = (char *) f + offsetof(struct funcnode, n);
+	funcstring = (char *) f + blocksize;
+	copynode(n);
+	f->count = 0;
+	return f;
+}
+
+
+
+STATIC void
+calcsize(n)
+	union node *n;
+{
+	%CALCSIZE
+}
+
+
+
+STATIC void
+sizenodelist(lp)
+	struct nodelist *lp;
+{
+	while (lp) {
+		funcblocksize += SHELL_ALIGN(sizeof(struct nodelist));
+		calcsize(lp->n);
+		lp = lp->next;
+	}
+}
+
+
+
+STATIC union node *
+copynode(n)
+	union node *n;
+{
+	union node *new;
+
+	%COPY
+	return new;
+}
+
+
+STATIC struct nodelist *
+copynodelist(lp)
+	struct nodelist *lp;
+{
+	struct nodelist *start;
+	struct nodelist **lpp;
+
+	lpp = &start;
+	while (lp) {
+		*lpp = funcblock;
+		funcblock = (char *) funcblock +
+		    SHELL_ALIGN(sizeof(struct nodelist));
+		(*lpp)->n = copynode(lp->n);
+		lp = lp->next;
+		lpp = &(*lpp)->next;
+	}
+	*lpp = NULL;
+	return start;
+}
+
+
+
+STATIC char *
+nodesavestr(s)
+	char   *s;
+{
+	char   *rtn = funcstring;
+
+	funcstring = stpcpy(funcstring, s) + 1;
+	return rtn;
+}
+
+
+
+/*
+ * Free a parse tree.
+ */
+
+void
+freefunc(struct funcnode *f)
+{
+	if (f && --f->count < 0)
+		ckfree(f);
+}
diff --git a/src/nodetypes b/src/nodetypes
new file mode 100644
index 00000000..ceaf478c
--- /dev/null
+++ b/src/nodetypes
@@ -0,0 +1,151 @@
+# Copyright (c) 1991, 1993
+#	The Regents of the University of California.  All rights reserved.
+# Copyright (c) 1997-2005
+#	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+#
+# This code is derived from software contributed to Berkeley by
+# Kenneth Almquist.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. Neither the name of the University nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+#	@(#)nodetypes	8.2 (Berkeley) 5/4/95
+
+# This file describes the nodes used in parse trees.  Unindented lines
+# contain a node type followed by a structure tag.  Subsequent indented
+# lines specify the fields of the structure.  Several node types can share
+# the same structure, in which case the fields of the structure should be
+# specified only once.
+#
+# A field of a structure is described by the name of the field followed
+# by a type.  The currently implemented types are:
+#	nodeptr - a pointer to a node
+#	nodelist - a pointer to a list of nodes
+#	string - a pointer to a nul terminated string
+#	int - an integer
+#	other - any type that can be copied by assignment
+#	temp - a field that doesn't have to be copied when the node is copied
+# The last two types should be followed by the text of a C declaration for
+# the field.
+
+NCMD ncmd			# a simple command
+	type	  int
+	linno	  int
+	assign    nodeptr		# variable assignments
+	args	  nodeptr		# the arguments
+	redirect  nodeptr		# list of file redirections
+
+NPIPE npipe			# a pipeline
+	type	  int
+	backgnd	  int			# set to run pipeline in background
+	cmdlist	  nodelist		# the commands in the pipeline
+
+NREDIR nredir			# redirection (of a complex command)
+	type	  int
+	linno	  int
+	n	  nodeptr		# the command
+	redirect  nodeptr		# list of file redirections
+
+NBACKGND nredir			# run command in background
+NSUBSHELL nredir		# run command in a subshell
+
+NAND nbinary			# the && operator
+NOR nbinary			# the || operator
+
+NSEMI nbinary			# two commands separated by a semicolon
+	type	  int
+	ch1	  nodeptr		# the first child
+	ch2	  nodeptr		# the second child
+
+NIF nif				# the if statement.  Elif clauses are handled
+	type	  int		    # using multiple if nodes.
+	test	  nodeptr		# if test
+	ifpart	  nodeptr		# then ifpart
+	elsepart  nodeptr		# else elsepart
+
+NWHILE nbinary			# the while statement.  First child is the test
+NUNTIL nbinary			# the until statement
+
+NFOR nfor			# the for statement
+	type	  int
+	linno	  int
+	args	  nodeptr		# for var in args
+	body	  nodeptr		# do body; done
+	var	  string		# the for variable
+
+NCASE ncase			# a case statement
+	type	  int
+	linno	  int
+	expr	  nodeptr		# the word to switch on
+	cases	  nodeptr		# the list of cases (NCLIST nodes)
+
+NCLIST nclist			# a case
+	type	  int
+	next	  nodeptr		# the next case in list
+	pattern	  nodeptr		# list of patterns for this case
+	body	  nodeptr		# code to execute for this case
+
+
+NDEFUN ndefun			# a function
+	type	  int
+	linno	  int
+	text	  string
+	body	  nodeptr
+
+NARG narg			# represents a word
+	type	  int
+	next	  nodeptr		# next word in list
+	text	  string		# the text of the word
+	backquote nodelist		# list of commands in back quotes
+
+NTO nfile			# fd> fname
+NCLOBBER nfile			# fd>| fname
+NFROM nfile			# fd< fname
+NFROMTO nfile			# fd<> fname
+NAPPEND nfile			# fd>> fname
+	type	  int
+	next	  nodeptr		# next redirection in list
+	fd	  int			# file descriptor being redirected
+	fname	  nodeptr		# file name, in a NARG node
+	expfname  temp	char *expfname	# actual file name
+
+NTOFD ndup			# fd<&dupfd
+NFROMFD ndup			# fd>&dupfd
+	type	  int
+	next	  nodeptr		# next redirection in list
+	fd	  int			# file descriptor being redirected
+	dupfd	  int			# file descriptor to duplicate
+	vname	  nodeptr		# file name if fd>&$var
+
+
+NHERE nhere			# fd<<\!
+NXHERE nhere			# fd<<!
+	type	  int
+	next	  nodeptr		# next redirection in list
+	fd	  int			# file descriptor being redirected
+	doc	  nodeptr		# input to command (NARG node)
+
+NNOT nnot			# ! command  (actually pipeline)
+	type	int
+	com	nodeptr
diff --git a/src/options.c b/src/options.c
new file mode 100644
index 00000000..a46c23b9
--- /dev/null
+++ b/src/options.c
@@ -0,0 +1,558 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <signal.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#include "shell.h"
+#define DEFINE_OPTIONS
+#include "options.h"
+#undef DEFINE_OPTIONS
+#include "nodes.h"	/* for other header files */
+#include "eval.h"
+#include "jobs.h"
+#include "input.h"
+#include "output.h"
+#include "trap.h"
+#include "var.h"
+#include "memalloc.h"
+#include "error.h"
+#include "mystring.h"
+#ifndef SMALL
+#include "myhistedit.h"
+#endif
+#include "show.h"
+
+char *arg0;			/* value of $0 */
+struct shparam shellparam;	/* current positional parameters */
+char **argptr;			/* argument list for builtin commands */
+char *optionarg;		/* set by nextopt (like getopt) */
+char *optptr;			/* used by nextopt */
+
+char *minusc;			/* argument to -c option */
+
+static const char *const optnames[NOPTS] = {
+	"errexit",
+	"noglob",
+	"ignoreeof",
+	"interactive",
+	"monitor",
+	"noexec",
+	"stdin",
+	"xtrace",
+	"verbose",
+	"vi",
+	"emacs",
+	"noclobber",
+	"allexport",
+	"notify",
+	"nounset",
+	"nolog",
+	"debug",
+};
+
+const char optletters[NOPTS] = {
+	'e',
+	'f',
+	'I',
+	'i',
+	'm',
+	'n',
+	's',
+	'x',
+	'v',
+	'V',
+	'E',
+	'C',
+	'a',
+	'b',
+	'u',
+	0,
+	0,
+};
+
+char optlist[NOPTS];
+
+
+static int options(int);
+STATIC void minus_o(char *, int);
+STATIC void setoption(int, int);
+STATIC int getopts(char *, char *, char **);
+
+
+/*
+ * Process the shell command line arguments.
+ */
+
+int
+procargs(int argc, char **argv)
+{
+	int i;
+	const char *xminusc;
+	char **xargv;
+	int login;
+
+	xargv = argv;
+	login = xargv[0] && xargv[0][0] == '-';
+	arg0 = xargv[0];
+	if (argc > 0)
+		xargv++;
+	for (i = 0; i < NOPTS; i++)
+		optlist[i] = 2;
+	argptr = xargv;
+	login |= options(1);
+	xargv = argptr;
+	xminusc = minusc;
+	if (*xargv == NULL) {
+		if (xminusc)
+			sh_error("-c requires an argument");
+		sflag = 1;
+	}
+	if (iflag == 2 && sflag == 1 && isatty(0) && isatty(1))
+		iflag = 1;
+	if (mflag == 2)
+		mflag = iflag;
+	for (i = 0; i < NOPTS; i++)
+		if (optlist[i] == 2)
+			optlist[i] = 0;
+#if DEBUG == 2
+	debug = 1;
+#endif
+	/* POSIX 1003.2: first arg after -c cmd is $0, remainder $1... */
+	if (xminusc) {
+		minusc = *xargv++;
+		if (*xargv)
+			goto setarg0;
+	} else if (!sflag) {
+		setinputfile(*xargv, 0);
+setarg0:
+		arg0 = *xargv++;
+	}
+
+	shellparam.p = xargv;
+	shellparam.optind = 1;
+	shellparam.optoff = -1;
+	/* assert(shellparam.malloc == 0 && shellparam.nparam == 0); */
+	while (*xargv) {
+		shellparam.nparam++;
+		xargv++;
+	}
+	optschanged();
+
+	return login;
+}
+
+
+void
+optschanged(void)
+{
+#ifdef DEBUG
+	opentrace();
+#endif
+	setinteractive(iflag);
+#ifndef SMALL
+	histedit();
+#endif
+	setjobctl(mflag);
+}
+
+/*
+ * Process shell options.  The global variable argptr contains a pointer
+ * to the argument list; we advance it past the options.
+ */
+
+STATIC int
+options(int cmdline)
+{
+	char *p;
+	int val;
+	int c;
+	int login = 0;
+
+	if (cmdline)
+		minusc = NULL;
+	while ((p = *argptr) != NULL) {
+		argptr++;
+		if ((c = *p++) == '-') {
+			val = 1;
+                        if (p[0] == '\0' || (p[0] == '-' && p[1] == '\0')) {
+                                if (!cmdline) {
+                                        /* "-" means turn off -x and -v */
+                                        if (p[0] == '\0')
+                                                xflag = vflag = 0;
+                                        /* "--" means reset params */
+                                        else if (*argptr == NULL)
+						setparam(argptr);
+                                }
+				break;	  /* "-" or  "--" terminates options */
+			}
+		} else if (c == '+') {
+			val = 0;
+		} else {
+			argptr--;
+			break;
+		}
+		while ((c = *p++) != '\0') {
+			if (c == 'c' && cmdline) {
+				minusc = p;	/* command is after shell args*/
+			} else if (c == 'l' && cmdline) {
+				login = 1;
+			} else if (c == 'o') {
+				minus_o(*argptr, val);
+				if (*argptr)
+					argptr++;
+			} else {
+				setoption(c, val);
+			}
+		}
+	}
+
+	return login;
+}
+
+STATIC void
+minus_o(char *name, int val)
+{
+	int i;
+
+	if (name == NULL) {
+		if (val) {
+			out1str("Current option settings\n");
+			for (i = 0; i < NOPTS; i++)
+				out1fmt("%-16s%s\n", optnames[i],
+					optlist[i] ? "on" : "off");
+		} else {
+			for (i = 0; i < NOPTS; i++)
+				out1fmt("set %s %s\n",
+					optlist[i] ? "-o" : "+o",
+					optnames[i]);
+
+		}
+	} else {
+		for (i = 0; i < NOPTS; i++)
+			if (equal(name, optnames[i])) {
+				optlist[i] = val;
+				return;
+			}
+		sh_error("Illegal option -o %s", name);
+	}
+}
+
+
+STATIC void
+setoption(int flag, int val)
+{
+	int i;
+
+	for (i = 0; i < NOPTS; i++)
+		if (optletters[i] == flag) {
+			optlist[i] = val;
+			if (val) {
+				/* #%$ hack for ksh semantics */
+				if (flag == 'V')
+					Eflag = 0;
+				else if (flag == 'E')
+					Vflag = 0;
+			}
+			return;
+		}
+	sh_error("Illegal option -%c", flag);
+	/* NOTREACHED */
+}
+
+
+
+/*
+ * Set the shell parameters.
+ */
+
+void
+setparam(char **argv)
+{
+	char **newparam;
+	char **ap;
+	int nparam;
+
+	for (nparam = 0 ; argv[nparam] ; nparam++);
+	ap = newparam = ckmalloc((nparam + 1) * sizeof *ap);
+	while (*argv) {
+		*ap++ = savestr(*argv++);
+	}
+	*ap = NULL;
+	freeparam(&shellparam);
+	shellparam.malloc = 1;
+	shellparam.nparam = nparam;
+	shellparam.p = newparam;
+	shellparam.optind = 1;
+	shellparam.optoff = -1;
+}
+
+
+/*
+ * Free the list of positional parameters.
+ */
+
+void
+freeparam(volatile struct shparam *param)
+{
+	char **ap;
+
+	if (param->malloc) {
+		for (ap = param->p ; *ap ; ap++)
+			ckfree(*ap);
+		ckfree(param->p);
+	}
+}
+
+
+
+/*
+ * The shift builtin command.
+ */
+
+int
+shiftcmd(int argc, char **argv)
+{
+	int n;
+	char **ap1, **ap2;
+
+	n = 1;
+	if (argc > 1)
+		n = number(argv[1]);
+	if (n > shellparam.nparam)
+		sh_error("can't shift that many");
+	INTOFF;
+	shellparam.nparam -= n;
+	for (ap1 = shellparam.p ; --n >= 0 ; ap1++) {
+		if (shellparam.malloc)
+			ckfree(*ap1);
+	}
+	ap2 = shellparam.p;
+	while ((*ap2++ = *ap1++) != NULL);
+	shellparam.optind = 1;
+	shellparam.optoff = -1;
+	INTON;
+	return 0;
+}
+
+
+
+/*
+ * The set command builtin.
+ */
+
+int
+setcmd(int argc, char **argv)
+{
+	if (argc == 1)
+		return showvars(nullstr, 0, VUNSET);
+	INTOFF;
+	options(0);
+	optschanged();
+	if (*argptr != NULL) {
+		setparam(argptr);
+	}
+	INTON;
+	return 0;
+}
+
+
+void
+getoptsreset(value)
+	const char *value;
+{
+	shellparam.optind = number(value) ?: 1;
+	shellparam.optoff = -1;
+}
+
+/*
+ * The getopts builtin.  Shellparam.optnext points to the next argument
+ * to be processed.  Shellparam.optptr points to the next character to
+ * be processed in the current argument.  If shellparam.optnext is NULL,
+ * then it's the first time getopts has been called.
+ */
+
+int
+getoptscmd(int argc, char **argv)
+{
+	char **optbase;
+
+	if (argc < 3)
+		sh_error("Usage: getopts optstring var [arg]");
+	else if (argc == 3) {
+		optbase = shellparam.p;
+		if ((unsigned)shellparam.optind > shellparam.nparam + 1) {
+			shellparam.optind = 1;
+			shellparam.optoff = -1;
+		}
+	}
+	else {
+		optbase = &argv[3];
+		if ((unsigned)shellparam.optind > argc - 2) {
+			shellparam.optind = 1;
+			shellparam.optoff = -1;
+		}
+	}
+
+	return getopts(argv[1], argv[2], optbase);
+}
+
+STATIC int
+getopts(char *optstr, char *optvar, char **optfirst)
+{
+	char *p, *q;
+	char c = '?';
+	int done = 0;
+	char s[2];
+	char **optnext;
+	int ind = shellparam.optind;
+	int off = shellparam.optoff;
+
+	shellparam.optind = -1;
+	optnext = optfirst + ind - 1;
+
+	if (ind <= 1 || off < 0 || strlen(optnext[-1]) < off)
+		p = NULL;
+	else
+		p = optnext[-1] + off;
+	if (p == NULL || *p == '\0') {
+		/* Current word is done, advance */
+		p = *optnext;
+		if (p == NULL || *p != '-' || *++p == '\0') {
+atend:
+			p = NULL;
+			done = 1;
+			goto out;
+		}
+		optnext++;
+		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
+			goto atend;
+	}
+
+	c = *p++;
+	for (q = optstr; *q != c; ) {
+		if (*q == '\0') {
+			if (optstr[0] == ':') {
+				s[0] = c;
+				s[1] = '\0';
+				setvar("OPTARG", s, 0);
+			} else {
+				outfmt(&errout, "Illegal option -%c\n", c);
+				(void) unsetvar("OPTARG");
+			}
+			c = '?';
+			goto out;
+		}
+		if (*++q == ':')
+			q++;
+	}
+
+	if (*++q == ':') {
+		if (*p == '\0' && (p = *optnext) == NULL) {
+			if (optstr[0] == ':') {
+				s[0] = c;
+				s[1] = '\0';
+				setvar("OPTARG", s, 0);
+				c = ':';
+			} else {
+				outfmt(&errout, "No arg for -%c option\n", c);
+				(void) unsetvar("OPTARG");
+				c = '?';
+			}
+			goto out;
+		}
+
+		if (p == *optnext)
+			optnext++;
+		setvar("OPTARG", p, 0);
+		p = NULL;
+	} else
+		setvar("OPTARG", nullstr, 0);
+
+out:
+	ind = optnext - optfirst + 1;
+	setvarint("OPTIND", ind, VNOFUNC);
+	s[0] = c;
+	s[1] = '\0';
+	setvar(optvar, s, 0);
+
+	shellparam.optoff = p ? p - *(optnext - 1) : -1;
+	shellparam.optind = ind;
+
+	return done;
+}
+
+/*
+ * XXX - should get rid of.  have all builtins use getopt(3).  the
+ * library getopt must have the BSD extension static variable "optreset"
+ * otherwise it can't be used within the shell safely.
+ *
+ * Standard option processing (a la getopt) for builtin routines.  The
+ * only argument that is passed to nextopt is the option string; the
+ * other arguments are unnecessary.  It return the character, or '\0' on
+ * end of input.
+ */
+
+int
+nextopt(const char *optstring)
+{
+	char *p;
+	const char *q;
+	char c;
+
+	if ((p = optptr) == NULL || *p == '\0') {
+		p = *argptr;
+		if (p == NULL || *p != '-' || *++p == '\0')
+			return '\0';
+		argptr++;
+		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
+			return '\0';
+	}
+	c = *p++;
+	for (q = optstring ; *q != c ; ) {
+		if (*q == '\0')
+			sh_error("Illegal option -%c", c);
+		if (*++q == ':')
+			q++;
+	}
+	if (*++q == ':') {
+		if (*p == '\0' && (p = *argptr++) == NULL)
+			sh_error("No arg for -%c option", c);
+		optionarg = p;
+		p = NULL;
+	}
+	optptr = p;
+	return c;
+}
diff --git a/src/options.h b/src/options.h
new file mode 100644
index 00000000..975fe339
--- /dev/null
+++ b/src/options.h
@@ -0,0 +1,86 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)options.h	8.2 (Berkeley) 5/4/95
+ */
+
+struct shparam {
+	int nparam;		/* # of positional parameters (without $0) */
+	unsigned char malloc;	/* if parameter list dynamically allocated */
+	char **p;		/* parameter list */
+	int optind;		/* next parameter to be processed by getopts */
+	int optoff;		/* used by getopts */
+};
+
+
+
+#define eflag optlist[0]
+#define fflag optlist[1]
+#define Iflag optlist[2]
+#define iflag optlist[3]
+#define mflag optlist[4]
+#define nflag optlist[5]
+#define sflag optlist[6]
+#define xflag optlist[7]
+#define vflag optlist[8]
+#define Vflag optlist[9]
+#define	Eflag optlist[10]
+#define	Cflag optlist[11]
+#define	aflag optlist[12]
+#define	bflag optlist[13]
+#define	uflag optlist[14]
+#define	nolog optlist[15]
+#define	debug optlist[16]
+
+#define NOPTS	17
+
+extern const char optletters[NOPTS];
+extern char optlist[NOPTS];
+
+
+extern char *minusc;		/* argument to -c option */
+extern char *arg0;		/* $0 */
+extern struct shparam shellparam;  /* $@ */
+extern char **argptr;		/* argument list for builtin commands */
+extern char *optionarg;		/* set by nextopt */
+extern char *optptr;		/* used by nextopt */
+
+int procargs(int, char **);
+void optschanged(void);
+void setparam(char **);
+void freeparam(volatile struct shparam *);
+int shiftcmd(int, char **);
+int setcmd(int, char **);
+int getoptscmd(int, char **);
+int nextopt(const char *);
+void getoptsreset(const char *);
diff --git a/src/output.c b/src/output.c
new file mode 100644
index 00000000..e9ee9b4d
--- /dev/null
+++ b/src/output.c
@@ -0,0 +1,429 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Shell output routines.  We use our own output routines because:
+ *	When a builtin command is interrupted we have to discard
+ *		any pending output.
+ *	When a builtin command appears in back quotes, we want to
+ *		save the output of the command in a region obtained
+ *		via malloc, rather than doing a fork and reading the
+ *		output of the command via a pipe.
+ *	Our output routines may be smaller than the stdio routines.
+ */
+
+#include <sys/types.h>		/* quad_t */
+#include <sys/param.h>		/* BSD4_4 */
+#include <sys/ioctl.h>
+
+#include <stdio.h>	/* defines BUFSIZ */
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#ifdef USE_GLIBC_STDIO
+#include <fcntl.h>
+#endif
+#include <limits.h>
+
+#include "shell.h"
+#include "syntax.h"
+#include "output.h"
+#include "memalloc.h"
+#include "error.h"
+#include "main.h"
+#include "system.h"
+
+
+#define OUTBUFSIZ BUFSIZ
+#define MEM_OUT -3		/* output to dynamically allocated memory */
+
+
+#ifdef USE_GLIBC_STDIO
+struct output output = {
+	.stream = 0, .nextc = 0, .end = 0, .buf = 0, .bufsize = 0, .fd = 1, .flags = 0
+};
+struct output errout = {
+	.stream = 0, .nextc = 0, .end = 0, .buf = 0, .bufsize = 0, .fd = 2, .flags = 0
+}
+#ifdef notyet
+struct output memout = {
+	.stream = 0, .nextc = 0, .end = 0, .buf = 0, .bufsize = 0, .fd = MEM_OUT, .flags = 0
+};
+#endif
+#else
+struct output output = {
+	.nextc = 0, .end = 0, .buf = 0, .bufsize = OUTBUFSIZ, .fd = 1, .flags = 0
+};
+struct output errout = {
+	.nextc = 0, .end = 0, .buf = 0, .bufsize = 0, .fd = 2, .flags = 0
+};
+struct output preverrout;
+#ifdef notyet
+struct output memout = {
+	.nextc = 0, .end = 0, .buf = 0, .bufsize = 0, .fd = MEM_OUT, .flags = 0
+};
+#endif
+#endif
+struct output *out1 = &output;
+struct output *out2 = &errout;
+
+
+static int xvsnprintf(char *, size_t, const char *, va_list);
+
+
+#ifdef mkinit
+
+INCLUDE "output.h"
+INCLUDE "memalloc.h"
+
+INIT {
+#ifdef USE_GLIBC_STDIO
+	initstreams();
+#endif
+}
+
+RESET {
+#ifdef notyet
+	out1 = &output;
+	out2 = &errout;
+#ifdef USE_GLIBC_STDIO
+	if (memout.stream != NULL)
+		__closememout();
+#endif
+	if (memout.buf != NULL) {
+		ckfree(memout.buf);
+		memout.buf = NULL;
+	}
+#endif
+}
+
+#endif
+
+
+void
+outmem(const char *p, size_t len, struct output *dest)
+{
+#ifdef USE_GLIBC_STDIO
+	INTOFF;
+	fwrite(p, 1, len, dest->stream);
+	INTON;
+#else
+	size_t bufsize;
+	size_t offset;
+	size_t nleft;
+
+	nleft = dest->end - dest->nextc;
+	if (likely(nleft >= len)) {
+buffered:
+		dest->nextc = mempcpy(dest->nextc, p, len);
+		return;
+	}
+
+	bufsize = dest->bufsize;
+	if (!bufsize) {
+		;
+	} else if (dest->buf == NULL) {
+#ifdef notyet
+		if (dest->fd == MEM_OUT && len > bufsize) {
+			bufsize = len;
+		}
+#endif
+		offset = 0;
+#ifdef notyet
+		goto alloc;
+	} else if (dest->fd == MEM_OUT) {
+		offset = bufsize;
+		if (bufsize >= len) {
+			bufsize <<= 1;
+		} else {
+			bufsize += len;
+		}
+		if (bufsize < offset)
+			goto err;
+alloc:
+#endif
+		INTOFF;
+		dest->buf = ckrealloc(dest->buf, bufsize);
+		dest->bufsize = bufsize;
+		dest->end = dest->buf + bufsize;
+		dest->nextc = dest->buf + offset;
+		INTON;
+	} else {
+		flushout(dest);
+	}
+
+	nleft = dest->end - dest->nextc;
+	if (nleft > len)
+		goto buffered;
+
+	if ((xwrite(dest->fd, p, len))) {
+#ifdef notyet
+err:
+#endif
+		dest->flags |= OUTPUT_ERR;
+	}
+#endif
+}
+
+
+void
+outstr(const char *p, struct output *file)
+{
+#ifdef USE_GLIBC_STDIO
+	INTOFF;
+	fputs(p, file->stream);
+	INTON;
+#else
+	size_t len;
+
+	len = strlen(p);
+	outmem(p, len, file);
+#endif
+}
+
+
+#ifndef USE_GLIBC_STDIO
+
+
+void
+outcslow(int c, struct output *dest)
+{
+	char buf = c;
+	outmem(&buf, 1, dest);
+}
+#endif
+
+
+void
+flushall(void)
+{
+	flushout(&output);
+#ifdef FLUSHERR
+	flushout(&errout);
+#endif
+}
+
+
+void
+flushout(struct output *dest)
+{
+#ifdef USE_GLIBC_STDIO
+	INTOFF;
+	fflush(dest->stream);
+	INTON;
+#else
+	size_t len;
+
+	len = dest->nextc - dest->buf;
+	if (!len || dest->fd < 0)
+		return;
+	dest->nextc = dest->buf;
+	if ((xwrite(dest->fd, dest->buf, len)))
+		dest->flags |= OUTPUT_ERR;
+#endif
+}
+
+
+void
+outfmt(struct output *file, const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	doformat(file, fmt, ap);
+	va_end(ap);
+}
+
+
+void
+out1fmt(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	doformat(out1, fmt, ap);
+	va_end(ap);
+}
+
+
+int
+fmtstr(char *outbuf, size_t length, const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+
+	va_start(ap, fmt);
+	ret = xvsnprintf(outbuf, length, fmt, ap);
+	va_end(ap);
+	return ret > (int)length ? length : ret;
+}
+
+
+static int xvasprintf(char **sp, size_t size, const char *f, va_list ap)
+{
+	char *s;
+	int len;
+	va_list ap2;
+
+	va_copy(ap2, ap);
+	len = xvsnprintf(*sp, size, f, ap2);
+	va_end(ap2);
+	if (len < 0)
+		sh_error("xvsnprintf failed");
+	if (len < size)
+		return len;
+
+	s = stalloc((len >= stackblocksize() ? len : stackblocksize()) + 1);
+	*sp = s;
+	len = xvsnprintf(s, len + 1, f, ap);
+	return len;
+}
+
+
+int xasprintf(char **sp, const char *f, ...)
+{
+	va_list ap;
+	int ret;
+
+	va_start(ap, f);
+	ret = xvasprintf(sp, 0, f, ap);
+	va_end(ap);
+	return ret;
+}
+
+
+#ifndef USE_GLIBC_STDIO
+void
+doformat(struct output *dest, const char *f, va_list ap)
+{
+	struct stackmark smark;
+	char *s;
+	int len;
+	int olen;
+
+	setstackmark(&smark);
+	s = dest->nextc;
+	olen = dest->end - dest->nextc;
+	len = xvasprintf(&s, olen, f, ap);
+	if (likely(olen > len)) {
+		dest->nextc += len;
+		goto out;
+	}
+	outmem(s, len, dest);
+out:
+	popstackmark(&smark);
+}
+#endif
+
+
+
+/*
+ * Version of write which resumes after a signal is caught.
+ */
+
+int
+xwrite(int fd, const void *p, size_t n)
+{
+	const char *buf = p;
+
+	while (n) {
+		ssize_t i;
+		size_t m;
+
+		m = n;
+		if (m > SSIZE_MAX)
+			m = SSIZE_MAX;
+		do {
+			i = write(fd, buf, m);
+		} while (i < 0 && errno == EINTR);
+		if (i < 0)
+			return -1;
+		buf += i;
+		n -= i;
+	}
+	return 0;
+}
+
+
+#ifdef notyet
+#ifdef USE_GLIBC_STDIO
+void initstreams() {
+	output.stream = stdout;
+	errout.stream = stderr;
+}
+
+
+void
+openmemout(void) {
+	INTOFF;
+	memout.stream = open_memstream(&memout.buf, &memout.bufsize);
+	INTON;
+}
+
+
+int
+__closememout(void) {
+	int error;
+	error = fclose(memout.stream);
+	memout.stream = NULL;
+	return error;
+}
+#endif
+#endif
+
+
+static int
+xvsnprintf(char *outbuf, size_t length, const char *fmt, va_list ap)
+{
+	int ret;
+
+#ifdef __sun
+	/*
+	 * vsnprintf() on older versions of Solaris returns -1 when
+	 * passed a length of 0.  To avoid this, use a dummy
+	 * 1-character buffer instead.
+	 */
+	char dummy[1];
+
+	if (length == 0) {
+		outbuf = dummy;
+		length = sizeof(dummy);
+	}
+#endif
+
+	INTOFF;
+	ret = vsnprintf(outbuf, length, fmt, ap);
+	INTON;
+	return ret;
+}
diff --git a/src/output.h b/src/output.h
new file mode 100644
index 00000000..c43d4937
--- /dev/null
+++ b/src/output.h
@@ -0,0 +1,126 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)output.h	8.2 (Berkeley) 5/4/95
+ */
+
+#ifndef OUTPUT_INCL
+
+#include <stdarg.h>
+#ifdef USE_GLIBC_STDIO
+#include <stdio.h>
+#endif
+#include <sys/types.h>
+
+struct output {
+#ifdef USE_GLIBC_STDIO
+	FILE *stream;
+#endif
+	char *nextc;
+	char *end;
+	char *buf;
+	size_t bufsize;
+	int fd;
+	int flags;
+};
+
+extern struct output output;
+extern struct output errout;
+extern struct output preverrout;
+#ifdef notyet
+extern struct output memout;
+#endif
+extern struct output *out1;
+extern struct output *out2;
+
+void outmem(const char *, size_t, struct output *);
+void outstr(const char *, struct output *);
+#ifndef USE_GLIBC_STDIO
+void outcslow(int, struct output *);
+#endif
+void flushall(void);
+void flushout(struct output *);
+void outfmt(struct output *, const char *, ...)
+    __attribute__((__format__(__printf__,2,3)));
+void out1fmt(const char *, ...)
+    __attribute__((__format__(__printf__,1,2)));
+int fmtstr(char *, size_t, const char *, ...)
+    __attribute__((__format__(__printf__,3,4)));
+int xasprintf(char **, const char *, ...);
+#ifndef USE_GLIBC_STDIO
+void doformat(struct output *, const char *, va_list);
+#endif
+int xwrite(int, const void *, size_t);
+#ifdef notyet
+#ifdef USE_GLIBC_STDIO
+void initstreams(void);
+void openmemout(void);
+int __closememout(void);
+#endif
+#endif
+
+static inline void
+freestdout()
+{
+	output.nextc = output.buf;
+	output.flags = 0;
+}
+
+#define OUTPUT_ERR 01		/* error occurred on output */
+
+#ifdef USE_GLIBC_STDIO
+static inline void outc(int ch, struct output *file)
+{
+	putc(ch, file->stream);
+}
+#define doformat(d, f, a)	vfprintf((d)->stream, (f), (a))
+#else
+static inline void outc(int ch, struct output *file)
+{
+	if (file->nextc == file->end)
+		outcslow(ch, file);
+	else {
+		*file->nextc = ch;
+		file->nextc++;
+	}
+}
+#endif
+#define out1c(c)	outc((c), out1)
+#define out2c(c)	outcslow((c), out2)
+#define out1mem(s, l)	outmem((s), (l), out1)
+#define out1str(s)	outstr((s), out1)
+#define out2str(s)	outstr((s), out2)
+#define outerr(f)	(f)->flags
+
+#define OUTPUT_INCL
+#endif
diff --git a/src/parser.c b/src/parser.c
new file mode 100644
index 00000000..a47022e0
--- /dev/null
+++ b/src/parser.c
@@ -0,0 +1,1647 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if HAVE_ALLOCA_H
+#include <alloca.h>
+#endif
+
+#include <stdlib.h>
+
+#include "shell.h"
+#include "parser.h"
+#include "nodes.h"
+#include "expand.h"	/* defines rmescapes() */
+#include "exec.h"	/* defines find_builtin() */
+#include "syntax.h"
+#include "options.h"
+#include "input.h"
+#include "output.h"
+#include "var.h"
+#include "error.h"
+#include "memalloc.h"
+#include "mystring.h"
+#include "alias.h"
+#include "show.h"
+#include "builtins.h"
+#include "system.h"
+#ifndef SMALL
+#include "myhistedit.h"
+#endif
+
+/*
+ * Shell command parser.
+ */
+
+/* values returned by readtoken */
+#include "token_vars.h"
+
+
+
+/* Used by expandstr to get here-doc like behaviour. */
+#define FAKEEOFMARK (char *)1
+
+
+
+struct heredoc {
+	struct heredoc *next;	/* next here document in list */
+	union node *here;		/* redirection node */
+	char *eofmark;		/* string indicating end of input */
+	int striptabs;		/* if set, strip leading tabs */
+};
+
+struct synstack {
+	const char *syntax;
+	struct synstack *prev;
+	struct synstack *next;
+	int innerdq;
+	int varpushed;
+	int dblquote;
+	int varnest;		/* levels of variables expansion */
+	int parenlevel;		/* levels of parens in arithmetic */
+	int dqvarnest;		/* levels of variables expansion within double quotes */
+};
+
+
+
+struct heredoc *heredoclist;	/* list of here documents to read */
+int doprompt;			/* if set, prompt the user */
+int needprompt;			/* true if interactive and at start of line */
+int lasttoken;			/* last token read */
+int tokpushback;		/* last token pushed back */
+char *wordtext;			/* text of last word returned by readtoken */
+int checkkwd;
+struct nodelist *backquotelist;
+union node *redirnode;
+struct heredoc *heredoc;
+int quoteflag;			/* set if (part of) last token was quoted */
+
+
+STATIC union node *list(int);
+STATIC union node *andor(void);
+STATIC union node *pipeline(void);
+STATIC union node *command(void);
+STATIC union node *simplecmd(void);
+STATIC union node *makename(void);
+STATIC void parsefname(void);
+STATIC void parseheredoc(void);
+STATIC int readtoken(void);
+STATIC int xxreadtoken(void);
+STATIC int pgetc_eatbnl();
+STATIC int readtoken1(int, char const *, char *, int);
+STATIC void synexpect(int) __attribute__((__noreturn__));
+STATIC void synerror(const char *) __attribute__((__noreturn__));
+STATIC void setprompt(int);
+
+
+int isassignment(const char *p)
+{
+	const char *q = endofname(p);
+	if (p == q)
+		return 0;
+	return *q == '=';
+}
+
+static inline int realeofmark(const char *eofmark)
+{
+	return eofmark && eofmark != FAKEEOFMARK;
+}
+
+
+/*
+ * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
+ * valid parse tree indicating a blank line.)
+ */
+
+union node *
+parsecmd(int interact)
+{
+	tokpushback = 0;
+	checkkwd = 0;
+	heredoclist = 0;
+	doprompt = interact;
+	if (doprompt)
+		setprompt(doprompt);
+	needprompt = 0;
+	return list(1);
+}
+
+
+STATIC union node *
+list(int nlflag)
+{
+	int chknl = nlflag & 1 ? 0 : CHKNL;
+	union node *n1, *n2, *n3;
+	int tok;
+
+	n1 = NULL;
+	for (;;) {
+		checkkwd = chknl | CHKKWD | CHKALIAS;
+		tok = readtoken();
+		switch (tok) {
+		case TNL:
+			parseheredoc();
+			return n1;
+
+		case TEOF:
+			if (!n1 && !chknl)
+				n1 = NEOF;
+out_eof:
+			parseheredoc();
+			tokpushback++;
+			lasttoken = TEOF;
+			return n1;
+		}
+
+		tokpushback++;
+		if (nlflag == 2 && tokendlist[tok])
+			return n1;
+		nlflag |= 2;
+
+		n2 = andor();
+		tok = readtoken();
+		if (tok == TBACKGND) {
+			if (n2->type == NPIPE) {
+				n2->npipe.backgnd = 1;
+			} else {
+				if (n2->type != NREDIR) {
+					n3 = stalloc(sizeof(struct nredir));
+					n3->nredir.n = n2;
+					n3->nredir.redirect = NULL;
+					n2 = n3;
+				}
+				n2->type = NBACKGND;
+			}
+		}
+		if (n1 == NULL) {
+			n1 = n2;
+		}
+		else {
+			n3 = (union node *)stalloc(sizeof (struct nbinary));
+			n3->type = NSEMI;
+			n3->nbinary.ch1 = n1;
+			n3->nbinary.ch2 = n2;
+			n1 = n3;
+		}
+		switch (tok) {
+		case TEOF:
+			goto out_eof;
+		case TNL:
+			tokpushback++;
+			/* fall through */
+		case TBACKGND:
+		case TSEMI:
+			break;
+		default:
+			if (!chknl)
+				synexpect(-1);
+			tokpushback++;
+			return n1;
+		}
+	}
+}
+
+
+
+STATIC union node *
+andor(void)
+{
+	union node *n1, *n2, *n3;
+	int t;
+
+	n1 = pipeline();
+	for (;;) {
+		if ((t = readtoken()) == TAND) {
+			t = NAND;
+		} else if (t == TOR) {
+			t = NOR;
+		} else {
+			tokpushback++;
+			return n1;
+		}
+		checkkwd = CHKNL | CHKKWD | CHKALIAS;
+		n2 = pipeline();
+		n3 = (union node *)stalloc(sizeof (struct nbinary));
+		n3->type = t;
+		n3->nbinary.ch1 = n1;
+		n3->nbinary.ch2 = n2;
+		n1 = n3;
+	}
+}
+
+
+
+STATIC union node *
+pipeline(void)
+{
+	union node *n1, *n2, *pipenode;
+	struct nodelist *lp, *prev;
+	int negate;
+
+	negate = 0;
+	TRACE(("pipeline: entered\n"));
+	if (readtoken() == TNOT) {
+		negate = !negate;
+		checkkwd = CHKKWD | CHKALIAS;
+	} else
+		tokpushback++;
+	n1 = command();
+	if (readtoken() == TPIPE) {
+		pipenode = (union node *)stalloc(sizeof (struct npipe));
+		pipenode->type = NPIPE;
+		pipenode->npipe.backgnd = 0;
+		lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
+		pipenode->npipe.cmdlist = lp;
+		lp->n = n1;
+		do {
+			prev = lp;
+			lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
+			checkkwd = CHKNL | CHKKWD | CHKALIAS;
+			lp->n = command();
+			prev->next = lp;
+		} while (readtoken() == TPIPE);
+		lp->next = NULL;
+		n1 = pipenode;
+	}
+	tokpushback++;
+	if (negate) {
+		n2 = (union node *)stalloc(sizeof (struct nnot));
+		n2->type = NNOT;
+		n2->nnot.com = n1;
+		return n2;
+	} else
+		return n1;
+}
+
+
+
+STATIC union node *
+command(void)
+{
+	union node *n1, *n2;
+	union node *ap, **app;
+	union node *cp, **cpp;
+	union node *redir, **rpp;
+	union node **rpp2;
+	int t;
+	int savelinno;
+
+	redir = NULL;
+	rpp2 = &redir;
+
+	savelinno = plinno;
+
+	switch (readtoken()) {
+	default:
+		synexpect(-1);
+		/* NOTREACHED */
+	case TIF:
+		n1 = (union node *)stalloc(sizeof (struct nif));
+		n1->type = NIF;
+		n1->nif.test = list(0);
+		if (readtoken() != TTHEN)
+			synexpect(TTHEN);
+		n1->nif.ifpart = list(0);
+		n2 = n1;
+		while (readtoken() == TELIF) {
+			n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
+			n2 = n2->nif.elsepart;
+			n2->type = NIF;
+			n2->nif.test = list(0);
+			if (readtoken() != TTHEN)
+				synexpect(TTHEN);
+			n2->nif.ifpart = list(0);
+		}
+		if (lasttoken == TELSE)
+			n2->nif.elsepart = list(0);
+		else {
+			n2->nif.elsepart = NULL;
+			tokpushback++;
+		}
+		t = TFI;
+		break;
+	case TWHILE:
+	case TUNTIL: {
+		int got;
+		n1 = (union node *)stalloc(sizeof (struct nbinary));
+		n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL;
+		n1->nbinary.ch1 = list(0);
+		if ((got=readtoken()) != TDO) {
+TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : ""));
+			synexpect(TDO);
+		}
+		n1->nbinary.ch2 = list(0);
+		t = TDONE;
+		break;
+	}
+	case TFOR:
+		if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
+			synerror("Bad for loop variable");
+		n1 = (union node *)stalloc(sizeof (struct nfor));
+		n1->type = NFOR;
+		n1->nfor.linno = savelinno;
+		n1->nfor.var = wordtext;
+		checkkwd = CHKNL | CHKKWD | CHKALIAS;
+		if (readtoken() == TIN) {
+			app = &ap;
+			while (readtoken() == TWORD) {
+				n2 = (union node *)stalloc(sizeof (struct narg));
+				n2->type = NARG;
+				n2->narg.text = wordtext;
+				n2->narg.backquote = backquotelist;
+				*app = n2;
+				app = &n2->narg.next;
+			}
+			*app = NULL;
+			n1->nfor.args = ap;
+			if (lasttoken != TNL && lasttoken != TSEMI)
+				synexpect(-1);
+		} else {
+			n2 = (union node *)stalloc(sizeof (struct narg));
+			n2->type = NARG;
+			n2->narg.text = (char *)dolatstr;
+			n2->narg.backquote = NULL;
+			n2->narg.next = NULL;
+			n1->nfor.args = n2;
+			/*
+			 * Newline or semicolon here is optional (but note
+			 * that the original Bourne shell only allowed NL).
+			 */
+			if (lasttoken != TSEMI)
+				tokpushback++;
+		}
+		checkkwd = CHKNL | CHKKWD | CHKALIAS;
+		if (readtoken() != TDO)
+			synexpect(TDO);
+		n1->nfor.body = list(0);
+		t = TDONE;
+		break;
+	case TCASE:
+		n1 = (union node *)stalloc(sizeof (struct ncase));
+		n1->type = NCASE;
+		n1->ncase.linno = savelinno;
+		if (readtoken() != TWORD)
+			synexpect(TWORD);
+		n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg));
+		n2->type = NARG;
+		n2->narg.text = wordtext;
+		n2->narg.backquote = backquotelist;
+		n2->narg.next = NULL;
+		checkkwd = CHKNL | CHKKWD | CHKALIAS;
+		if (readtoken() != TIN)
+			synexpect(TIN);
+		cpp = &n1->ncase.cases;
+next_case:
+		checkkwd = CHKNL | CHKKWD;
+		t = readtoken();
+		while(t != TESAC) {
+			if (lasttoken == TLP)
+				readtoken();
+			*cpp = cp = (union node *)stalloc(sizeof (struct nclist));
+			cp->type = NCLIST;
+			app = &cp->nclist.pattern;
+			for (;;) {
+				*app = ap = (union node *)stalloc(sizeof (struct narg));
+				ap->type = NARG;
+				ap->narg.text = wordtext;
+				ap->narg.backquote = backquotelist;
+				if (readtoken() != TPIPE)
+					break;
+				app = &ap->narg.next;
+				readtoken();
+			}
+			ap->narg.next = NULL;
+			if (lasttoken != TRP)
+				synexpect(TRP);
+			cp->nclist.body = list(2);
+
+			cpp = &cp->nclist.next;
+
+			checkkwd = CHKNL | CHKKWD;
+			if ((t = readtoken()) != TESAC) {
+				if (t != TENDCASE)
+					synexpect(TENDCASE);
+				else
+					goto next_case;
+			}
+		}
+		*cpp = NULL;
+		goto redir;
+	case TLP:
+		n1 = (union node *)stalloc(sizeof (struct nredir));
+		n1->type = NSUBSHELL;
+		n1->nredir.linno = savelinno;
+		n1->nredir.n = list(0);
+		n1->nredir.redirect = NULL;
+		t = TRP;
+		break;
+	case TBEGIN:
+		n1 = list(0);
+		t = TEND;
+		break;
+	case TWORD:
+	case TREDIR:
+		tokpushback++;
+		return simplecmd();
+	}
+
+	if (readtoken() != t)
+		synexpect(t);
+
+redir:
+	/* Now check for redirection which may follow command */
+	checkkwd = CHKKWD | CHKALIAS;
+	rpp = rpp2;
+	while (readtoken() == TREDIR) {
+		*rpp = n2 = redirnode;
+		rpp = &n2->nfile.next;
+		parsefname();
+	}
+	tokpushback++;
+	*rpp = NULL;
+	if (redir) {
+		if (n1->type != NSUBSHELL) {
+			n2 = (union node *)stalloc(sizeof (struct nredir));
+			n2->type = NREDIR;
+			n2->nredir.linno = savelinno;
+			n2->nredir.n = n1;
+			n1 = n2;
+		}
+		n1->nredir.redirect = redir;
+	}
+
+	return n1;
+}
+
+
+STATIC union node *
+simplecmd(void) {
+	union node *args, **app;
+	union node *n = NULL;
+	union node *vars, **vpp;
+	union node **rpp, *redir;
+	int savecheckkwd;
+	int savelinno;
+
+	args = NULL;
+	app = &args;
+	vars = NULL;
+	vpp = &vars;
+	redir = NULL;
+	rpp = &redir;
+
+	savecheckkwd = CHKALIAS;
+	savelinno = plinno;
+	for (;;) {
+		checkkwd = savecheckkwd;
+		switch (readtoken()) {
+		case TWORD:
+			n = (union node *)stalloc(sizeof (struct narg));
+			n->type = NARG;
+			n->narg.text = wordtext;
+			n->narg.backquote = backquotelist;
+			if (savecheckkwd && isassignment(wordtext)) {
+				*vpp = n;
+				vpp = &n->narg.next;
+			} else {
+				*app = n;
+				app = &n->narg.next;
+				savecheckkwd = 0;
+			}
+			break;
+		case TREDIR:
+			*rpp = n = redirnode;
+			rpp = &n->nfile.next;
+			parsefname();	/* read name of redirection file */
+			break;
+		case TLP:
+			if (
+				args && app == &args->narg.next &&
+				!vars && !redir
+			) {
+				struct builtincmd *bcmd;
+				const char *name;
+
+				/* We have a function */
+				if (readtoken() != TRP)
+					synexpect(TRP);
+				name = n->narg.text;
+				if (
+					!goodname(name) || (
+						(bcmd = find_builtin(name)) &&
+						bcmd->flags & BUILTIN_SPECIAL
+					)
+				)
+					synerror("Bad function name");
+				n->type = NDEFUN;
+				checkkwd = CHKNL | CHKKWD | CHKALIAS;
+				n->ndefun.text = n->narg.text;
+				n->ndefun.linno = plinno;
+				n->ndefun.body = command();
+				return n;
+			}
+			/* fall through */
+		default:
+			tokpushback++;
+			goto out;
+		}
+	}
+out:
+	*app = NULL;
+	*vpp = NULL;
+	*rpp = NULL;
+	n = (union node *)stalloc(sizeof (struct ncmd));
+	n->type = NCMD;
+	n->ncmd.linno = savelinno;
+	n->ncmd.args = args;
+	n->ncmd.assign = vars;
+	n->ncmd.redirect = redir;
+	return n;
+}
+
+STATIC union node *
+makename(void)
+{
+	union node *n;
+
+	n = (union node *)stalloc(sizeof (struct narg));
+	n->type = NARG;
+	n->narg.next = NULL;
+	n->narg.text = wordtext;
+	n->narg.backquote = backquotelist;
+	return n;
+}
+
+void fixredir(union node *n, const char *text, int err)
+	{
+	TRACE(("Fix redir %s %d\n", text, err));
+	if (!err)
+		n->ndup.vname = NULL;
+
+	if (is_digit(text[0]) && text[1] == '\0')
+		n->ndup.dupfd = digit_val(text[0]);
+	else if (text[0] == '-' && text[1] == '\0')
+		n->ndup.dupfd = -1;
+	else {
+
+		if (err)
+			synerror("Bad fd number");
+		else
+			n->ndup.vname = makename();
+	}
+}
+
+
+STATIC void
+parsefname(void)
+{
+	union node *n = redirnode;
+
+	if (n->type == NHERE)
+		checkkwd = CHKEOFMARK;
+	if (readtoken() != TWORD)
+		synexpect(-1);
+	if (n->type == NHERE) {
+		struct heredoc *here = heredoc;
+		struct heredoc *p;
+
+		if (quoteflag == 0)
+			n->type = NXHERE;
+		TRACE(("Here document %d\n", n->type));
+		rmescapes(wordtext);
+		here->eofmark = wordtext;
+		here->next = NULL;
+		if (heredoclist == NULL)
+			heredoclist = here;
+		else {
+			for (p = heredoclist ; p->next ; p = p->next);
+			p->next = here;
+		}
+	} else if (n->type == NTOFD || n->type == NFROMFD) {
+		fixredir(n, wordtext, 0);
+	} else {
+		n->nfile.fname = makename();
+	}
+}
+
+
+/*
+ * Input any here documents.
+ */
+
+STATIC void
+parseheredoc(void)
+{
+	struct heredoc *here;
+	union node *n;
+
+	here = heredoclist;
+	heredoclist = 0;
+
+	while (here) {
+		if (needprompt) {
+			setprompt(2);
+		}
+		if (here->here->type == NHERE)
+			readtoken1(pgetc(), SQSYNTAX, here->eofmark, here->striptabs);
+		else
+			readtoken1(pgetc_eatbnl(), DQSYNTAX, here->eofmark, here->striptabs);
+		n = (union node *)stalloc(sizeof (struct narg));
+		n->narg.type = NARG;
+		n->narg.next = NULL;
+		n->narg.text = wordtext;
+		n->narg.backquote = backquotelist;
+		here->here->nhere.doc = n;
+		here = here->next;
+	}
+}
+
+STATIC int
+readtoken(void)
+{
+	int t;
+	int kwd = checkkwd;
+#ifdef DEBUG
+	int alreadyseen = tokpushback;
+#endif
+
+top:
+	t = xxreadtoken();
+
+	/*
+	 * eat newlines
+	 */
+	if (kwd & CHKNL) {
+		while (t == TNL) {
+			parseheredoc();
+			checkkwd = 0;
+			t = xxreadtoken();
+		}
+	}
+
+	kwd |= checkkwd;
+	checkkwd = 0;
+
+	if (t != TWORD || quoteflag) {
+		goto out;
+	}
+
+	/*
+	 * check for keywords
+	 */
+	if (kwd & CHKKWD) {
+		const char *const *pp;
+
+		if ((pp = findkwd(wordtext))) {
+			lasttoken = t = pp - parsekwd + KWDOFFSET;
+			TRACE(("keyword %s recognized\n", tokname[t]));
+			goto out;
+		}
+	}
+
+	if (kwd & CHKALIAS) {
+		struct alias *ap;
+		if ((ap = lookupalias(wordtext, 1)) != NULL) {
+			if (*ap->val) {
+				pushstring(ap->val, ap);
+			}
+			goto top;
+		}
+	}
+out:
+#ifdef DEBUG
+	if (!alreadyseen)
+	    TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
+	else
+	    TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : ""));
+#endif
+	return (t);
+}
+
+static void nlprompt(void)
+{
+	plinno++;
+	if (doprompt)
+		setprompt(2);
+}
+
+static void nlnoprompt(void)
+{
+	plinno++;
+	needprompt = doprompt;
+}
+
+
+/*
+ * Read the next input token.
+ * If the token is a word, we set backquotelist to the list of cmds in
+ *	backquotes.  We set quoteflag to true if any part of the word was
+ *	quoted.
+ * If the token is TREDIR, then we set redirnode to a structure containing
+ *	the redirection.
+ *
+ * [Change comment:  here documents and internal procedures]
+ * [Readtoken shouldn't have any arguments.  Perhaps we should make the
+ *  word parsing code into a separate routine.  In this case, readtoken
+ *  doesn't need to have any internal procedures, but parseword does.
+ *  We could also make parseoperator in essence the main routine, and
+ *  have parseword (readtoken1?) handle both words and redirection.]
+ */
+
+#define RETURN(token)	return lasttoken = token
+
+STATIC int
+xxreadtoken(void)
+{
+	int c;
+
+	if (tokpushback) {
+		tokpushback = 0;
+		return lasttoken;
+	}
+	if (needprompt) {
+		setprompt(2);
+	}
+	for (;;) {	/* until token or start of word found */
+		c = pgetc_eatbnl();
+		switch (c) {
+		case ' ': case '\t':
+		case PEOA:
+			continue;
+		case '#':
+			while ((c = pgetc()) != '\n' && c != PEOF);
+			pungetc();
+			continue;
+		case '\n':
+			nlnoprompt();
+			RETURN(TNL);
+		case PEOF:
+			RETURN(TEOF);
+		case '&':
+			if (pgetc_eatbnl() == '&')
+				RETURN(TAND);
+			pungetc();
+			RETURN(TBACKGND);
+		case '|':
+			if (pgetc_eatbnl() == '|')
+				RETURN(TOR);
+			pungetc();
+			RETURN(TPIPE);
+		case ';':
+			if (pgetc_eatbnl() == ';')
+				RETURN(TENDCASE);
+			pungetc();
+			RETURN(TSEMI);
+		case '(':
+			RETURN(TLP);
+		case ')':
+			RETURN(TRP);
+		}
+		break;
+	}
+	return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
+#undef RETURN
+}
+
+static int pgetc_eatbnl(void)
+{
+	int c;
+
+	while ((c = pgetc()) == '\\') {
+		if (pgetc2() != '\n') {
+			pungetc();
+			break;
+		}
+
+		nlprompt();
+	}
+
+	return c;
+}
+
+static int pgetc_top(struct synstack *stack)
+{
+	return stack->syntax == SQSYNTAX ? pgetc() : pgetc_eatbnl();
+}
+
+static void synstack_push(struct synstack **stack, struct synstack *next,
+			  const char *syntax)
+{
+	memset(next, 0, sizeof(*next));
+	next->syntax = syntax;
+	next->next = *stack;
+	(*stack)->prev = next;
+	*stack = next;
+}
+
+static void synstack_pop(struct synstack **stack)
+{
+	*stack = (*stack)->next;
+}
+
+
+
+/*
+ * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
+ * is not NULL, read a here document.  In the latter case, eofmark is the
+ * word which marks the end of the document and striptabs is true if
+ * leading tabs should be stripped from the document.  The argument firstc
+ * is the first character of the input token or document.
+ *
+ * Because C does not have internal subroutines, I have simulated them
+ * using goto's to implement the subroutine linkage.  The following macros
+ * will run code that appears at the end of readtoken1.
+ */
+
+#define CHECKEND()	{goto checkend; checkend_return:;}
+#define PARSEREDIR()	{goto parseredir; parseredir_return:;}
+#define PARSESUB()	{goto parsesub; parsesub_return:;}
+#define PARSEBACKQOLD()	{oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
+#define PARSEBACKQNEW()	{oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
+#define	PARSEARITH()	{goto parsearith; parsearith_return:;}
+
+STATIC int
+readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs)
+{
+	int c = firstc;
+	char *out;
+	size_t len;
+	struct nodelist *bqlist;
+	int quotef;
+	int oldstyle;
+	/* syntax stack */
+	struct synstack synbase = { .syntax = syntax };
+	struct synstack *synstack = &synbase;
+
+	if (syntax == DQSYNTAX)
+		synstack->dblquote = 1;
+	quotef = 0;
+	bqlist = NULL;
+
+	STARTSTACKSTR(out);
+	loop: {	/* for each line, until end of word */
+#if ATTY
+		if (c == '\034' && doprompt
+		 && attyset() && ! equal(termval(), "emacs")) {
+			attyline();
+			if (synstack->syntax == BASESYNTAX)
+				return readtoken();
+			c = pgetc_top(synstack);
+			goto loop;
+		}
+#endif
+		CHECKEND();	/* set c to PEOF if at end of here document */
+		for (;;) {	/* until end of line or end of word */
+			CHECKSTRSPACE(4, out);	/* permit 4 calls to USTPUTC */
+			switch(synstack->syntax[c]) {
+			case CNL:	/* '\n' */
+				if (synstack->syntax == BASESYNTAX &&
+				    !synstack->varnest)
+					goto endword;	/* exit outer loop */
+				USTPUTC(c, out);
+				nlprompt();
+				c = pgetc_top(synstack);
+				goto loop;		/* continue outer loop */
+			case CWORD:
+				USTPUTC(c, out);
+				break;
+			case CCTL:
+				if ((!eofmark) | synstack->dblquote |
+				    synstack->varnest)
+					USTPUTC(CTLESC, out);
+				USTPUTC(c, out);
+				break;
+			/* backslash */
+			case CBACK:
+				c = pgetc2();
+				if (c == PEOF) {
+					USTPUTC(CTLESC, out);
+					USTPUTC('\\', out);
+					pungetc();
+				} else {
+					if (
+						synstack->dblquote &&
+						c != '\\' && c != '`' &&
+						c != '$' && (
+							c != '"' ||
+							(eofmark != NULL &&
+							 !synstack->varnest)
+						) && (
+							c != '}' ||
+							!synstack->varnest
+						)
+					) {
+						USTPUTC(CTLESC, out);
+						USTPUTC('\\', out);
+					}
+					USTPUTC(CTLESC, out);
+					USTPUTC(c, out);
+					quotef++;
+				}
+				break;
+			case CSQUOTE:
+				synstack->syntax = SQSYNTAX;
+quotemark:
+				if (eofmark == NULL) {
+					USTPUTC(CTLQUOTEMARK, out);
+				}
+				break;
+			case CDQUOTE:
+				synstack->syntax = DQSYNTAX;
+				synstack->dblquote = 1;
+toggledq:
+				if (synstack->varnest)
+					synstack->innerdq ^= 1;
+				goto quotemark;
+			case CENDQUOTE:
+				if (eofmark && !synstack->varnest) {
+					USTPUTC(c, out);
+					break;
+				}
+
+				if (synstack->dqvarnest == 0) {
+					synstack->syntax = BASESYNTAX;
+					synstack->dblquote = 0;
+				}
+
+				quotef++;
+
+				if (c == '"')
+					goto toggledq;
+
+				goto quotemark;
+			case CVAR:	/* '$' */
+				PARSESUB();		/* parse substitution */
+				break;
+			case CENDVAR:	/* '}' */
+				if (!synstack->innerdq &&
+				    synstack->varnest > 0) {
+					if (!--synstack->varnest &&
+					    synstack->varpushed)
+						synstack_pop(&synstack);
+					else if (synstack->dqvarnest > 0)
+						synstack->dqvarnest--;
+					USTPUTC(CTLENDVAR, out);
+				} else {
+					USTPUTC(c, out);
+				}
+				break;
+			case CLP:	/* '(' in arithmetic */
+				synstack->parenlevel++;
+				USTPUTC(c, out);
+				break;
+			case CRP:	/* ')' in arithmetic */
+				if (synstack->parenlevel > 0) {
+					USTPUTC(c, out);
+					--synstack->parenlevel;
+				} else {
+					if (pgetc_eatbnl() == ')') {
+						USTPUTC(CTLENDARI, out);
+						synstack_pop(&synstack);
+					} else {
+						/*
+						 * unbalanced parens
+						 *  (don't 2nd guess - no error)
+						 */
+						pungetc();
+						USTPUTC(')', out);
+					}
+				}
+				break;
+			case CBQUOTE:	/* '`' */
+				if (checkkwd & CHKEOFMARK) {
+					USTPUTC('`', out);
+					break;
+				}
+
+				PARSEBACKQOLD();
+				break;
+			case CEOF:
+				goto endword;		/* exit outer loop */
+			case CIGN:
+				break;
+			default:
+				if (synstack->varnest == 0)
+					goto endword;	/* exit outer loop */
+				if (c != PEOA) {
+					USTPUTC(c, out);
+				}
+			}
+			c = pgetc_top(synstack);
+		}
+	}
+endword:
+	if (synstack->syntax == ARISYNTAX)
+		synerror("Missing '))'");
+	if (synstack->syntax != BASESYNTAX && eofmark == NULL)
+		synerror("Unterminated quoted string");
+	if (synstack->varnest != 0) {
+		/* { */
+		synerror("Missing '}'");
+	}
+	USTPUTC('\0', out);
+	len = out - (char *)stackblock();
+	out = stackblock();
+	if (eofmark == NULL) {
+		if ((c == '>' || c == '<')
+		 && quotef == 0
+		 && len <= 2
+		 && (*out == '\0' || is_digit(*out))) {
+			PARSEREDIR();
+			return lasttoken = TREDIR;
+		} else {
+			pungetc();
+		}
+	}
+	quoteflag = quotef;
+	backquotelist = bqlist;
+	grabstackblock(len);
+	wordtext = out;
+	return lasttoken = TWORD;
+/* end of readtoken routine */
+
+
+
+/*
+ * Check to see whether we are at the end of the here document.  When this
+ * is called, c is set to the first character of the next input line.  If
+ * we are at the end of the here document, this routine sets the c to PEOF.
+ */
+
+checkend: {
+	if (realeofmark(eofmark)) {
+		int markloc;
+		char *p;
+
+		if (c == PEOA) {
+			c = pgetc2();
+		}
+		if (striptabs) {
+			while (c == '\t') {
+				c = pgetc2();
+			}
+		}
+
+		markloc = out - (char *)stackblock();
+		for (p = eofmark; STPUTC(c, out), *p; p++) {
+			if (c != *p)
+				goto more_heredoc;
+
+			c = pgetc2();
+		}
+
+		if (c == '\n' || c == PEOF) {
+			c = PEOF;
+			nlnoprompt();
+		} else {
+			int len;
+
+more_heredoc:
+			p = (char *)stackblock() + markloc + 1;
+			len = out - p;
+
+			if (len) {
+				len -= c < 0;
+				c = p[-1];
+
+				if (len) {
+					char *str;
+
+					str = alloca(len + 1);
+					*(char *)mempcpy(str, p, len) = 0;
+
+					pushstring(str, NULL);
+				}
+			}
+		}
+
+		STADJUST((char *)stackblock() + markloc - out, out);
+	}
+	goto checkend_return;
+}
+
+
+/*
+ * Parse a redirection operator.  The variable "out" points to a string
+ * specifying the fd to be redirected.  The variable "c" contains the
+ * first character of the redirection operator.
+ */
+
+parseredir: {
+	char fd = *out;
+	union node *np;
+
+	np = (union node *)stalloc(sizeof (struct nfile));
+	if (c == '>') {
+		np->nfile.fd = 1;
+		c = pgetc_eatbnl();
+		if (c == '>')
+			np->type = NAPPEND;
+		else if (c == '|')
+			np->type = NCLOBBER;
+		else if (c == '&')
+			np->type = NTOFD;
+		else {
+			np->type = NTO;
+			pungetc();
+		}
+	} else {	/* c == '<' */
+		np->nfile.fd = 0;
+		switch (c = pgetc_eatbnl()) {
+		case '<':
+			if (sizeof (struct nfile) != sizeof (struct nhere)) {
+				np = (union node *)stalloc(sizeof (struct nhere));
+				np->nfile.fd = 0;
+			}
+			np->type = NHERE;
+			heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
+			heredoc->here = np;
+			if ((c = pgetc_eatbnl()) == '-') {
+				heredoc->striptabs = 1;
+			} else {
+				heredoc->striptabs = 0;
+				pungetc();
+			}
+			break;
+
+		case '&':
+			np->type = NFROMFD;
+			break;
+
+		case '>':
+			np->type = NFROMTO;
+			break;
+
+		default:
+			np->type = NFROM;
+			pungetc();
+			break;
+		}
+	}
+	if (fd != '\0')
+		np->nfile.fd = digit_val(fd);
+	redirnode = np;
+	goto parseredir_return;
+}
+
+
+/*
+ * Parse a substitution.  At this point, we have read the dollar sign
+ * and nothing else.
+ */
+
+parsesub: {
+	int subtype;
+	int typeloc;
+	char *p;
+	static const char types[] = "}-+?=";
+
+	c = pgetc_eatbnl();
+	if (
+		(checkkwd & CHKEOFMARK) ||
+		c <= PEOA  ||
+		(c != '(' && c != '{' && !is_name(c) && !is_special(c))
+	) {
+		USTPUTC('$', out);
+		pungetc();
+	} else if (c == '(') {	/* $(command) or $((arith)) */
+		if (pgetc_eatbnl() == '(') {
+			PARSEARITH();
+		} else {
+			pungetc();
+			PARSEBACKQNEW();
+		}
+	} else {
+		const char *newsyn = synstack->syntax;
+
+		USTPUTC(CTLVAR, out);
+		typeloc = out - (char *)stackblock();
+		STADJUST(1, out);
+		subtype = VSNORMAL;
+		if (likely(c == '{')) {
+			c = pgetc_eatbnl();
+			subtype = 0;
+		}
+varname:
+		if (is_name(c)) {
+			do {
+				STPUTC(c, out);
+				c = pgetc_eatbnl();
+			} while (is_in_name(c));
+		} else if (is_digit(c)) {
+			do {
+				STPUTC(c, out);
+				c = pgetc_eatbnl();
+			} while (!subtype && is_digit(c));
+		} else if (c != '}') {
+			int cc = c;
+
+			c = pgetc_eatbnl();
+
+			if (!subtype && cc == '#') {
+				subtype = VSLENGTH;
+
+				if (c == '_' || isalnum(c))
+					goto varname;
+
+				cc = c;
+				c = pgetc_eatbnl();
+				if (cc == '}' || c != '}') {
+					pungetc();
+					subtype = 0;
+					c = cc;
+					cc = '#';
+				}
+			}
+
+			if (!is_special(cc)) {
+				if (subtype == VSLENGTH)
+					subtype = 0;
+				goto badsub;
+			}
+
+			USTPUTC(cc, out);
+		} else
+			goto badsub;
+
+		if (subtype == 0) {
+			int cc = c;
+
+			switch (c) {
+			case ':':
+				subtype = VSNUL;
+				c = pgetc_eatbnl();
+				/*FALLTHROUGH*/
+			default:
+				p = strchr(types, c);
+				if (p == NULL)
+					break;
+				subtype |= p - types + VSNORMAL;
+				break;
+			case '%':
+			case '#':
+				subtype = c == '#' ? VSTRIMLEFT :
+						     VSTRIMRIGHT;
+				c = pgetc_eatbnl();
+				if (c == cc)
+					subtype++;
+				else
+					pungetc();
+
+				newsyn = BASESYNTAX;
+				break;
+			}
+		} else {
+badsub:
+			pungetc();
+		}
+
+		if (newsyn == ARISYNTAX)
+			newsyn = DQSYNTAX;
+
+		if ((newsyn != synstack->syntax || synstack->innerdq) &&
+		    subtype != VSNORMAL) {
+			synstack_push(&synstack,
+				      synstack->prev ?:
+				      alloca(sizeof(*synstack)),
+				      newsyn);
+
+			synstack->varpushed++;
+			synstack->dblquote = newsyn != BASESYNTAX;
+		}
+
+		*((char *)stackblock() + typeloc) = subtype;
+		if (subtype != VSNORMAL) {
+			synstack->varnest++;
+			if (synstack->dblquote)
+				synstack->dqvarnest++;
+		}
+		STPUTC('=', out);
+	}
+	goto parsesub_return;
+}
+
+
+/*
+ * Called to parse command substitutions.  Newstyle is set if the command
+ * is enclosed inside $(...); nlpp is a pointer to the head of the linked
+ * list of commands (passed by reference), and savelen is the number of
+ * characters on the top of the stack which must be preserved.
+ */
+
+parsebackq: {
+	struct nodelist **nlpp;
+	union node *n;
+	char *str;
+	size_t savelen;
+	struct heredoc *saveheredoclist;
+	int uninitialized_var(saveprompt);
+
+	str = NULL;
+	savelen = out - (char *)stackblock();
+	if (savelen > 0) {
+		str = alloca(savelen);
+		memcpy(str, stackblock(), savelen);
+	}
+        if (oldstyle) {
+                /* We must read until the closing backquote, giving special
+                   treatment to some slashes, and then push the string and
+                   reread it as input, interpreting it normally.  */
+                char *pout;
+                int pc;
+                size_t psavelen;
+                char *pstr;
+
+
+                STARTSTACKSTR(pout);
+		for (;;) {
+			if (needprompt) {
+				setprompt(2);
+			}
+			switch (pc = pgetc_eatbnl()) {
+			case '`':
+				goto done;
+
+			case '\\':
+                                pc = pgetc();
+                                if (pc != '\\' && pc != '`' && pc != '$'
+                                    && (!synstack->dblquote || pc != '"'))
+                                        STPUTC('\\', pout);
+				if (pc > PEOA) {
+					break;
+				}
+				/* fall through */
+
+			case PEOF:
+			case PEOA:
+				synerror("EOF in backquote substitution");
+
+			case '\n':
+				nlnoprompt();
+				break;
+
+			default:
+				break;
+			}
+			STPUTC(pc, pout);
+                }
+done:
+                STPUTC('\0', pout);
+                psavelen = pout - (char *)stackblock();
+                if (psavelen > 0) {
+			pstr = grabstackstr(pout);
+			setinputstring(pstr);
+                }
+        }
+	nlpp = &bqlist;
+	while (*nlpp)
+		nlpp = &(*nlpp)->next;
+	*nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
+	(*nlpp)->next = NULL;
+
+	saveheredoclist = heredoclist;
+	heredoclist = NULL;
+
+	if (oldstyle) {
+		saveprompt = doprompt;
+		doprompt = 0;
+	}
+
+	n = list(2);
+
+	if (oldstyle)
+		doprompt = saveprompt;
+	else {
+		if (readtoken() != TRP)
+			synexpect(TRP);
+		setinputstring(nullstr);
+	}
+
+	parseheredoc();
+	heredoclist = saveheredoclist;
+
+	(*nlpp)->n = n;
+	/* Start reading from old file again. */
+	popfile();
+	/* Ignore any pushed back tokens left from the backquote parsing. */
+	if (oldstyle)
+		tokpushback = 0;
+	out = growstackto(savelen + 1);
+	if (str) {
+		memcpy(out, str, savelen);
+		STADJUST(savelen, out);
+	}
+	USTPUTC(CTLBACKQ, out);
+	if (oldstyle)
+		goto parsebackq_oldreturn;
+	else
+		goto parsebackq_newreturn;
+}
+
+/*
+ * Parse an arithmetic expansion (indicate start of one and set state)
+ */
+parsearith: {
+
+	synstack_push(&synstack,
+		      synstack->prev ?: alloca(sizeof(*synstack)),
+		      ARISYNTAX);
+	synstack->dblquote = 1;
+	USTPUTC(CTLARI, out);
+	goto parsearith_return;
+}
+
+} /* end of readtoken */
+
+
+
+#ifdef mkinit
+INCLUDE "parser.h"
+#endif
+
+
+/*
+ * Return of a legal variable name (a letter or underscore followed by zero or
+ * more letters, underscores, and digits).
+ */
+
+char *
+endofname(const char *name)
+	{
+	char *p;
+
+	p = (char *) name;
+	if (! is_name(*p))
+		return p;
+	while (*++p) {
+		if (! is_in_name(*p))
+			break;
+	}
+	return p;
+}
+
+
+/*
+ * Called when an unexpected token is read during the parse.  The argument
+ * is the token that is expected, or -1 if more than one type of token can
+ * occur at this point.
+ */
+
+STATIC void
+synexpect(int token)
+{
+	char msg[64];
+
+	if (token >= 0) {
+		fmtstr(msg, 64, "%s unexpected (expecting %s)",
+			tokname[lasttoken], tokname[token]);
+	} else {
+		fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]);
+	}
+	synerror(msg);
+	/* NOTREACHED */
+}
+
+
+STATIC void
+synerror(const char *msg)
+{
+	errlinno = plinno;
+	sh_error("Syntax error: %s", msg);
+	/* NOTREACHED */
+}
+
+STATIC void
+setprompt(int which)
+{
+	struct stackmark smark;
+	int show;
+
+	needprompt = 0;
+	whichprompt = which;
+
+#ifdef SMALL
+	show = 1;
+#else
+	show = !el;
+#endif
+	if (show) {
+		pushstackmark(&smark, stackblocksize());
+		out2str(getprompt(NULL));
+		popstackmark(&smark);
+	}
+}
+
+const char *
+expandstr(const char *ps)
+{
+	struct parsefile *file_stop;
+	struct jmploc *volatile savehandler;
+	struct heredoc *saveheredoclist;
+	const char *result;
+	int saveprompt;
+	struct jmploc jmploc;
+	union node n;
+	int err;
+
+	file_stop = parsefile;
+
+	/* XXX Fix (char *) cast. */
+	setinputstring((char *)ps);
+
+	saveheredoclist = heredoclist;
+	heredoclist = NULL;
+	saveprompt = doprompt;
+	doprompt = 0;
+	result = ps;
+	savehandler = handler;
+	if (unlikely(err = setjmp(jmploc.loc)))
+		goto out;
+	handler = &jmploc;
+
+	readtoken1(pgetc_eatbnl(), DQSYNTAX, FAKEEOFMARK, 0);
+
+	n.narg.type = NARG;
+	n.narg.next = NULL;
+	n.narg.text = wordtext;
+	n.narg.backquote = backquotelist;
+
+	expandarg(&n, NULL, EXP_QUOTED);
+	result = stackblock();
+
+out:
+	handler = savehandler;
+	if (err && exception != EXERROR)
+		longjmp(handler->loc, 1);
+
+	doprompt = saveprompt;
+	unwindfiles(file_stop);
+	heredoclist = saveheredoclist;
+
+	return result;
+}
+
+/*
+ * called by editline -- any expansions to the prompt
+ *    should be added here.
+ */
+const char *
+getprompt(void *unused)
+{
+	const char *prompt;
+
+	switch (whichprompt) {
+	default:
+#ifdef DEBUG
+		return "<internal prompt error>";
+#endif
+	case 0:
+		return nullstr;
+	case 1:
+		prompt = ps1val();
+		break;
+	case 2:
+		prompt = ps2val();
+		break;
+	}
+
+	return expandstr(prompt);
+}
+
+const char *const *
+findkwd(const char *s)
+{
+	return findstring(
+		s, parsekwd, sizeof(parsekwd) / sizeof(const char *)
+	);
+}
diff --git a/src/parser.h b/src/parser.h
new file mode 100644
index 00000000..524ac1c7
--- /dev/null
+++ b/src/parser.h
@@ -0,0 +1,102 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)parser.h	8.3 (Berkeley) 5/4/95
+ */
+
+#include "token.h"
+
+/* control characters in argument strings */
+#define CTL_FIRST -127		/* first 'special' character */
+#define CTLESC -127		/* escape next character */
+#define CTLVAR -126		/* variable defn */
+#define CTLENDVAR -125
+#define CTLBACKQ -124
+#define	CTLARI -122		/* arithmetic expression */
+#define	CTLENDARI -121
+#define	CTLQUOTEMARK -120
+#define	CTL_LAST -120		/* last 'special' character */
+
+/* variable substitution byte (follows CTLVAR) */
+#define VSTYPE	0x0f		/* type of variable substitution */
+#define VSNUL	0x10		/* colon--treat the empty string as unset */
+
+/* values of VSTYPE field */
+#define VSNORMAL	0x1		/* normal variable:  $var or ${var} */
+#define VSMINUS		0x2		/* ${var-text} */
+#define VSPLUS		0x3		/* ${var+text} */
+#define VSQUESTION	0x4		/* ${var?message} */
+#define VSASSIGN	0x5		/* ${var=text} */
+#define VSTRIMRIGHT	0x6		/* ${var%pattern} */
+#define VSTRIMRIGHTMAX 	0x7		/* ${var%%pattern} */
+#define VSTRIMLEFT	0x8		/* ${var#pattern} */
+#define VSTRIMLEFTMAX	0x9		/* ${var##pattern} */
+#define VSLENGTH	0xa		/* ${#var} */
+
+/* values of checkkwd variable */
+#define CHKALIAS	0x1
+#define CHKKWD		0x2
+#define CHKNL		0x4
+#define CHKEOFMARK	0x8
+
+
+/*
+ * NEOF is returned by parsecmd when it encounters an end of file.  It
+ * must be distinct from NULL, so we use the address of a variable that
+ * happens to be handy.
+ */
+extern int lasttoken;
+extern int tokpushback;
+#define NEOF ((union node *)&tokpushback)
+extern int whichprompt;		/* 1 == PS1, 2 == PS2 */
+extern int checkkwd;
+
+
+int isassignment(const char *p);
+union node *parsecmd(int);
+void fixredir(union node *, const char *, int);
+const char *getprompt(void *);
+const char *const *findkwd(const char *);
+char *endofname(const char *);
+const char *expandstr(const char *);
+
+static inline int
+goodname(const char *p)
+{
+	return !*endofname(p);
+}
+
+static inline int parser_eof(void)
+{
+	return tokpushback && lasttoken == TEOF;
+}
diff --git a/src/redir.c b/src/redir.c
new file mode 100644
index 00000000..895140c3
--- /dev/null
+++ b/src/redir.c
@@ -0,0 +1,483 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/param.h>	/* PIPE_BUF */
+#include <signal.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+/*
+ * Code for dealing with input/output redirection.
+ */
+
+#include "main.h"
+#include "shell.h"
+#include "nodes.h"
+#include "jobs.h"
+#include "options.h"
+#include "expand.h"
+#include "redir.h"
+#include "output.h"
+#include "memalloc.h"
+#include "error.h"
+
+
+#define EMPTY -2		/* marks an unused slot in redirtab */
+#define CLOSED -1		/* fd opened for redir needs to be closed */
+
+#ifndef PIPE_BUF
+# define PIPESIZE 4096		/* amount of buffering in a pipe */
+#else
+# define PIPESIZE PIPE_BUF
+#endif
+
+
+MKINIT
+struct redirtab {
+	struct redirtab *next;
+	int renamed[10];
+};
+
+
+MKINIT struct redirtab *redirlist;
+
+/* Bit map of currently closed file descriptors. */
+static unsigned closed_redirs;
+
+STATIC int openredirect(union node *);
+#ifdef notyet
+STATIC void dupredirect(union node *, int, char[10]);
+#else
+STATIC void dupredirect(union node *, int);
+#endif
+STATIC int openhere(union node *);
+
+
+static unsigned update_closed_redirs(int fd, int nfd)
+{
+	unsigned val = closed_redirs;
+	unsigned bit = 1 << fd;
+
+	if (nfd >= 0)
+		closed_redirs &= ~bit;
+	else
+		closed_redirs |= bit;
+
+	return val & bit;
+}
+
+
+/*
+ * Process a list of redirection commands.  If the REDIR_PUSH flag is set,
+ * old file descriptors are stashed away so that the redirection can be
+ * undone by calling popredir.  If the REDIR_BACKQ flag is set, then the
+ * standard output, and the standard error if it becomes a duplicate of
+ * stdout, is saved in memory.
+ */
+
+void
+redirect(union node *redir, int flags)
+{
+	union node *n;
+	struct redirtab *sv;
+	int i;
+	int fd;
+	int newfd;
+	int *p;
+#if notyet
+	char memory[10];	/* file descriptors to write to memory */
+
+	for (i = 10 ; --i >= 0 ; )
+		memory[i] = 0;
+	memory[1] = flags & REDIR_BACKQ;
+#endif
+	if (!redir)
+		return;
+	sv = NULL;
+	INTOFF;
+	if (likely(flags & REDIR_PUSH))
+		sv = redirlist;
+	n = redir;
+	do {
+		newfd = openredirect(n);
+		if (newfd < -1)
+			continue;
+
+		fd = n->nfile.fd;
+
+		if (sv) {
+			int closed;
+
+			p = &sv->renamed[fd];
+			i = *p;
+
+			closed = update_closed_redirs(fd, newfd);
+
+			if (likely(i == EMPTY)) {
+				i = CLOSED;
+				if (fd != newfd && !closed) {
+					i = savefd(fd, fd);
+					fd = -1;
+				}
+			}
+
+			*p = i;
+		}
+
+		if (fd == newfd)
+			continue;
+
+#ifdef notyet
+		dupredirect(n, newfd, memory);
+#else
+		dupredirect(n, newfd);
+#endif
+	} while ((n = n->nfile.next));
+	INTON;
+#ifdef notyet
+	if (memory[1])
+		out1 = &memout;
+	if (memory[2])
+		out2 = &memout;
+#endif
+	if (flags & REDIR_SAVEFD2 && sv->renamed[2] >= 0)
+		preverrout.fd = sv->renamed[2];
+}
+
+
+STATIC int
+openredirect(union node *redir)
+{
+	struct stat64 sb;
+	char *fname;
+	int f;
+
+	switch (redir->nfile.type) {
+	case NFROM:
+		fname = redir->nfile.expfname;
+		if ((f = open64(fname, O_RDONLY)) < 0)
+			goto eopen;
+		break;
+	case NFROMTO:
+		fname = redir->nfile.expfname;
+		if ((f = open64(fname, O_RDWR|O_CREAT, 0666)) < 0)
+			goto ecreate;
+		break;
+	case NTO:
+		/* Take care of noclobber mode. */
+		if (Cflag) {
+			fname = redir->nfile.expfname;
+			if (stat64(fname, &sb) < 0) {
+				if ((f = open64(fname, O_WRONLY|O_CREAT|O_EXCL, 0666)) < 0)
+					goto ecreate;
+			} else if (!S_ISREG(sb.st_mode)) {
+				if ((f = open64(fname, O_WRONLY, 0666)) < 0)
+					goto ecreate;
+				if (!fstat64(f, &sb) && S_ISREG(sb.st_mode)) {
+					close(f);
+					errno = EEXIST;
+					goto ecreate;
+				}
+			} else {
+				errno = EEXIST;
+				goto ecreate;
+			}
+			break;
+		}
+		/* FALLTHROUGH */
+	case NCLOBBER:
+		fname = redir->nfile.expfname;
+		if ((f = open64(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) < 0)
+			goto ecreate;
+		break;
+	case NAPPEND:
+		fname = redir->nfile.expfname;
+		if ((f = open64(fname, O_WRONLY|O_CREAT|O_APPEND, 0666)) < 0)
+			goto ecreate;
+		break;
+	case NTOFD:
+	case NFROMFD:
+		f = redir->ndup.dupfd;
+		if (f == redir->nfile.fd)
+			f = -2;
+		break;
+	default:
+#ifdef DEBUG
+		abort();
+#endif
+		/* Fall through to eliminate warning. */
+	case NHERE:
+	case NXHERE:
+		f = openhere(redir);
+		break;
+	}
+
+	return f;
+ecreate:
+	sh_error("cannot create %s: %s", fname, errmsg(errno, E_CREAT));
+eopen:
+	sh_error("cannot open %s: %s", fname, errmsg(errno, E_OPEN));
+}
+
+
+STATIC void
+#ifdef notyet
+dupredirect(redir, f, memory)
+#else
+dupredirect(redir, f)
+#endif
+	union node *redir;
+	int f;
+#ifdef notyet
+	char memory[10];
+#endif
+	{
+	int fd = redir->nfile.fd;
+	int err = 0;
+
+#ifdef notyet
+	memory[fd] = 0;
+#endif
+	if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) {
+		/* if not ">&-" */
+		if (f >= 0) {
+#ifdef notyet
+			if (memory[f])
+				memory[fd] = 1;
+			else
+#endif
+				if (dup2(f, fd) < 0) {
+					err = errno;
+					goto err;
+				}
+			return;
+		}
+		f = fd;
+	} else if (dup2(f, fd) < 0)
+		err = errno;
+
+	close(f);
+	if (err < 0)
+		goto err;
+
+	return;
+
+err:
+	sh_error("%d: %s", f, strerror(err));
+}
+
+
+/*
+ * Handle here documents.  Normally we fork off a process to write the
+ * data to a pipe.  If the document is short, we can stuff the data in
+ * the pipe without forking.
+ */
+
+STATIC int
+openhere(union node *redir)
+{
+	char *p;
+	int pip[2];
+	size_t len = 0;
+
+	if (pipe(pip) < 0)
+		sh_error("Pipe call failed");
+
+	p = redir->nhere.doc->narg.text;
+	if (redir->type == NXHERE) {
+		expandarg(redir->nhere.doc, NULL, EXP_QUOTED);
+		p = stackblock();
+	}
+
+	len = strlen(p);
+	if (len <= PIPESIZE) {
+		xwrite(pip[1], p, len);
+		goto out;
+	}
+
+	if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) {
+		close(pip[0]);
+		signal(SIGINT, SIG_IGN);
+		signal(SIGQUIT, SIG_IGN);
+		signal(SIGHUP, SIG_IGN);
+#ifdef SIGTSTP
+		signal(SIGTSTP, SIG_IGN);
+#endif
+		signal(SIGPIPE, SIG_DFL);
+		xwrite(pip[1], p, len);
+		_exit(0);
+	}
+out:
+	close(pip[1]);
+	return pip[0];
+}
+
+
+
+/*
+ * Undo the effects of the last redirection.
+ */
+
+void
+popredir(int drop)
+{
+	struct redirtab *rp;
+	int i;
+
+	INTOFF;
+	rp = redirlist;
+	for (i = 0 ; i < 10 ; i++) {
+		int closed;
+
+		if (rp->renamed[i] == EMPTY)
+			continue;
+
+		closed = drop ? 1 : update_closed_redirs(i, rp->renamed[i]);
+
+		switch (rp->renamed[i]) {
+		case CLOSED:
+			if (!closed)
+				close(i);
+			break;
+		default:
+			if (!drop)
+				dup2(rp->renamed[i], i);
+			close(rp->renamed[i]);
+			break;
+		}
+	}
+	redirlist = rp->next;
+	ckfree(rp);
+	INTON;
+}
+
+/*
+ * Undo all redirections.  Called on error or interrupt.
+ */
+
+#ifdef mkinit
+
+INCLUDE "redir.h"
+
+EXITRESET {
+	/*
+	 * Discard all saved file descriptors.
+	 */
+	unwindredir(0);
+}
+
+FORKRESET {
+	redirlist = NULL;
+}
+
+#endif
+
+
+
+/*
+ * Move a file descriptor to > 10.  Invokes sh_error on error unless
+ * the original file dscriptor is not open.
+ */
+
+int
+savefd(int from, int ofd)
+{
+	int newfd;
+	int err;
+
+	newfd = fcntl(from, F_DUPFD, 10);
+	err = newfd < 0 ? errno : 0;
+	if (err != EBADF) {
+		close(ofd);
+		if (err)
+			sh_error("%d: %s", from, strerror(err));
+		else
+			fcntl(newfd, F_SETFD, FD_CLOEXEC);
+	}
+
+	return newfd;
+}
+
+
+int
+redirectsafe(union node *redir, int flags)
+{
+	int err;
+	volatile int saveint;
+	struct jmploc *volatile savehandler = handler;
+	struct jmploc jmploc;
+
+	SAVEINT(saveint);
+	if (!(err = setjmp(jmploc.loc) * 2)) {
+		handler = &jmploc;
+		redirect(redir, flags);
+	}
+	handler = savehandler;
+	if (err && exception != EXERROR)
+		longjmp(handler->loc, 1);
+	RESTOREINT(saveint);
+	return err;
+}
+
+
+void unwindredir(struct redirtab *stop)
+{
+	while (redirlist != stop)
+		popredir(0);
+}
+
+
+struct redirtab *pushredir(union node *redir)
+{
+	struct redirtab *sv;
+	struct redirtab *q;
+	int i;
+
+	q = redirlist;
+	if (!redir)
+		goto out;
+
+	sv = ckmalloc(sizeof (struct redirtab));
+	sv->next = q;
+	redirlist = sv;
+	for (i = 0; i < 10; i++)
+		sv->renamed[i] = EMPTY;
+
+out:
+	return q;
+}
diff --git a/src/redir.h b/src/redir.h
new file mode 100644
index 00000000..1cf27616
--- /dev/null
+++ b/src/redir.h
@@ -0,0 +1,52 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)redir.h	8.2 (Berkeley) 5/4/95
+ */
+
+/* flags passed to redirect */
+#define REDIR_PUSH 01		/* save previous values of file descriptors */
+#ifdef notyet
+#define REDIR_BACKQ 02		/* save the command output in memory */
+#endif
+#define REDIR_SAVEFD2 03	/* set preverrout */
+
+struct redirtab;
+union node;
+void redirect(union node *, int);
+void popredir(int);
+int savefd(int, int);
+int redirectsafe(union node *, int);
+void unwindredir(struct redirtab *stop);
+struct redirtab *pushredir(union node *redir);
+
diff --git a/src/shell.h b/src/shell.h
new file mode 100644
index 00000000..98edc8be
--- /dev/null
+++ b/src/shell.h
@@ -0,0 +1,104 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)shell.h	8.2 (Berkeley) 5/4/95
+ */
+
+/*
+ * The follow should be set to reflect the type of system you have:
+ *	JOBS -> 1 if you have Berkeley job control, 0 otherwise.
+ *	SHORTNAMES -> 1 if your linker cannot handle long names.
+ *	define BSD if you are running 4.2 BSD or later.
+ *	define SYSV if you are running under System V.
+ *	define DEBUG=1 to compile in debugging ('set -o debug' to turn on)
+ *	define DEBUG=2 to compile in and turn on debugging.
+ *	define DO_SHAREDVFORK to indicate that vfork(2) shares its address
+ *	       with its parent.
+ *
+ * When debugging is on, debugging info will be written to ./trace and
+ * a quit signal will generate a core dump.
+ */
+
+#include <sys/param.h>
+
+#ifndef JOBS
+#define JOBS 1
+#endif
+#ifndef BSD
+#define BSD 1
+#endif
+
+#ifndef DO_SHAREDVFORK
+#if __NetBSD_Version__ >= 104000000
+#define DO_SHAREDVFORK
+#endif
+#endif
+
+typedef void *pointer;
+#ifndef NULL
+#define NULL (void *)0
+#endif
+#define STATIC static
+#define MKINIT	/* empty */
+
+extern char nullstr[1];		/* null string */
+
+
+#ifdef DEBUG
+#define TRACE(param)	trace param
+#define TRACEV(param)	tracev param
+#else
+#define TRACE(param)
+#define TRACEV(param)
+#endif
+
+#if defined(__GNUC__) && __GNUC__ < 3
+#define va_copy __va_copy
+#endif
+
+#if !defined(__GNUC__) || (__GNUC__ == 2 && __GNUC_MINOR__ < 96)
+#define __builtin_expect(x, expected_value) (x)
+#endif
+
+#define likely(x)	__builtin_expect(!!(x),1)
+#define unlikely(x)	__builtin_expect(!!(x),0)
+
+/*
+ * Hack to calculate maximum length.
+ * (length * 8 - 1) * log10(2) + 1 + 1 + 12
+ * The second 1 is for the minus sign and the 12 is a safety margin.
+ */
+static inline int max_int_length(int bytes)
+{
+	return (bytes * 8 - 1) * 0.30102999566398119521 + 14;
+}
diff --git a/src/show.c b/src/show.c
new file mode 100644
index 00000000..4a049e93
--- /dev/null
+++ b/src/show.c
@@ -0,0 +1,406 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "shell.h"
+#include "parser.h"
+#include "nodes.h"
+#include "mystring.h"
+#include "show.h"
+#include "options.h"
+
+
+#ifdef DEBUG
+static void shtree(union node *, int, char *, FILE*);
+static void shcmd(union node *, FILE *);
+static void sharg(union node *, FILE *);
+static void indent(int, char *, FILE *);
+static void trstring(char *);
+
+
+void
+showtree(union node *n)
+{
+	trputs("showtree called\n");
+	shtree(n, 1, NULL, stdout);
+}
+
+
+static void
+shtree(union node *n, int ind, char *pfx, FILE *fp)
+{
+	struct nodelist *lp;
+	const char *s;
+
+	if (n == NULL)
+		return;
+
+	indent(ind, pfx, fp);
+	switch(n->type) {
+	case NSEMI:
+		s = "; ";
+		goto binop;
+	case NAND:
+		s = " && ";
+		goto binop;
+	case NOR:
+		s = " || ";
+binop:
+		shtree(n->nbinary.ch1, ind, NULL, fp);
+	   /*    if (ind < 0) */
+			fputs(s, fp);
+		shtree(n->nbinary.ch2, ind, NULL, fp);
+		break;
+	case NCMD:
+		shcmd(n, fp);
+		if (ind >= 0)
+			putc('\n', fp);
+		break;
+	case NPIPE:
+		for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
+			shcmd(lp->n, fp);
+			if (lp->next)
+				fputs(" | ", fp);
+		}
+		if (n->npipe.backgnd)
+			fputs(" &", fp);
+		if (ind >= 0)
+			putc('\n', fp);
+		break;
+	default:
+		fprintf(fp, "<node type %d>", n->type);
+		if (ind >= 0)
+			putc('\n', fp);
+		break;
+	}
+}
+
+
+
+static void
+shcmd(union node *cmd, FILE *fp)
+{
+	union node *np;
+	int first;
+	const char *s;
+	int dftfd;
+
+	first = 1;
+	for (np = cmd->ncmd.args ; np ; np = np->narg.next) {
+		if (! first)
+			putchar(' ');
+		sharg(np, fp);
+		first = 0;
+	}
+	for (np = cmd->ncmd.redirect ; np ; np = np->nfile.next) {
+		if (! first)
+			putchar(' ');
+		switch (np->nfile.type) {
+			case NTO:	s = ">";  dftfd = 1; break;
+			case NCLOBBER:	s = ">|"; dftfd = 1; break;
+			case NAPPEND:	s = ">>"; dftfd = 1; break;
+			case NTOFD:	s = ">&"; dftfd = 1; break;
+			case NFROM:	s = "<";  dftfd = 0; break;
+			case NFROMFD:	s = "<&"; dftfd = 0; break;
+			case NFROMTO:	s = "<>"; dftfd = 0; break;
+			default:  	s = "*error*"; dftfd = 0; break;
+		}
+		if (np->nfile.fd != dftfd)
+			fprintf(fp, "%d", np->nfile.fd);
+		fputs(s, fp);
+		if (np->nfile.type == NTOFD || np->nfile.type == NFROMFD) {
+			fprintf(fp, "%d", np->ndup.dupfd);
+		} else {
+			sharg(np->nfile.fname, fp);
+		}
+		first = 0;
+	}
+}
+
+
+
+static void
+sharg(union node *arg, FILE *fp)
+{
+	char *p;
+	struct nodelist *bqlist;
+	int subtype;
+
+	if (arg->type != NARG) {
+		printf("<node type %d>\n", arg->type);
+		abort();
+	}
+	bqlist = arg->narg.backquote;
+	for (p = arg->narg.text ; *p ; p++) {
+		switch ((signed char)*p) {
+		case CTLESC:
+			putc(*++p, fp);
+			break;
+		case CTLVAR:
+			putc('$', fp);
+			putc('{', fp);
+			subtype = *++p;
+			if (subtype == VSLENGTH)
+				putc('#', fp);
+
+			while (*p != '=')
+				putc(*p++, fp);
+
+			if (subtype & VSNUL)
+				putc(':', fp);
+
+			switch (subtype & VSTYPE) {
+			case VSNORMAL:
+				putc('}', fp);
+				break;
+			case VSMINUS:
+				putc('-', fp);
+				break;
+			case VSPLUS:
+				putc('+', fp);
+				break;
+			case VSQUESTION:
+				putc('?', fp);
+				break;
+			case VSASSIGN:
+				putc('=', fp);
+				break;
+			case VSTRIMLEFT:
+				putc('#', fp);
+				break;
+			case VSTRIMLEFTMAX:
+				putc('#', fp);
+				putc('#', fp);
+				break;
+			case VSTRIMRIGHT:
+				putc('%', fp);
+				break;
+			case VSTRIMRIGHTMAX:
+				putc('%', fp);
+				putc('%', fp);
+				break;
+			case VSLENGTH:
+				break;
+			default:
+				printf("<subtype %d>", subtype);
+			}
+			break;
+		case CTLENDVAR:
+		     putc('}', fp);
+		     break;
+		case CTLBACKQ:
+			putc('$', fp);
+			putc('(', fp);
+			shtree(bqlist->n, -1, NULL, fp);
+			putc(')', fp);
+			break;
+		default:
+			putc(*p, fp);
+			break;
+		}
+	}
+}
+
+
+static void
+indent(int amount, char *pfx, FILE *fp)
+{
+	int i;
+
+	for (i = 0 ; i < amount ; i++) {
+		if (pfx && i == amount - 1)
+			fputs(pfx, fp);
+		putc('\t', fp);
+	}
+}
+
+
+
+/*
+ * Debugging stuff.
+ */
+
+
+FILE *tracefile;
+
+
+void
+trputc(int c)
+{
+	if (debug != 1)
+		return;
+	putc(c, tracefile);
+}
+
+void
+trace(const char *fmt, ...)
+{
+	va_list va;
+
+	if (debug != 1)
+		return;
+	va_start(va, fmt);
+	(void) vfprintf(tracefile, fmt, va);
+	va_end(va);
+}
+
+void
+tracev(const char *fmt, va_list va)
+{
+	if (debug != 1)
+		return;
+	(void) vfprintf(tracefile, fmt, va);
+}
+
+
+void
+trputs(const char *s)
+{
+	if (debug != 1)
+		return;
+	fputs(s, tracefile);
+}
+
+
+static void
+trstring(char *s)
+{
+	char *p;
+	char c;
+
+	if (debug != 1)
+		return;
+	putc('"', tracefile);
+	for (p = s ; *p ; p++) {
+		switch ((signed char)*p) {
+		case '\n':  c = 'n';  goto backslash;
+		case '\t':  c = 't';  goto backslash;
+		case '\r':  c = 'r';  goto backslash;
+		case '"':  c = '"';  goto backslash;
+		case '\\':  c = '\\';  goto backslash;
+		case CTLESC:  c = 'e';  goto backslash;
+		case CTLVAR:  c = 'v';  goto backslash;
+		case CTLBACKQ:  c = 'q';  goto backslash;
+backslash:	  putc('\\', tracefile);
+			putc(c, tracefile);
+			break;
+		default:
+			if (*p >= ' ' && *p <= '~')
+				putc(*p, tracefile);
+			else {
+				putc('\\', tracefile);
+				putc(*p >> 6 & 03, tracefile);
+				putc(*p >> 3 & 07, tracefile);
+				putc(*p & 07, tracefile);
+			}
+			break;
+		}
+	}
+	putc('"', tracefile);
+}
+
+
+void
+trargs(char **ap)
+{
+	if (debug != 1)
+		return;
+	while (*ap) {
+		trstring(*ap++);
+		if (*ap)
+			putc(' ', tracefile);
+		else
+			putc('\n', tracefile);
+	}
+}
+
+
+void
+opentrace(void)
+{
+	char s[100];
+#ifdef O_APPEND
+	int flags;
+#endif
+
+	if (debug != 1) {
+		if (tracefile)
+			fflush(tracefile);
+		/* leave open because libedit might be using it */
+		return;
+	}
+#ifdef not_this_way
+	{
+		char *p;
+		if ((p = getenv(homestr)) == NULL) {
+			if (geteuid() == 0)
+				p = "/";
+			else
+				p = "/tmp";
+		}
+		scopy(p, s);
+		strcat(s, "/trace");
+	}
+#else
+	scopy("./trace", s);
+#endif /* not_this_way */
+	if (tracefile) {
+#ifndef __KLIBC__
+		if (!freopen(s, "a", tracefile)) {
+#else
+		if (!(!fclose(tracefile) && (tracefile = fopen(s, "a")))) {
+#endif /* __KLIBC__ */
+			fprintf(stderr, "Can't re-open %s\n", s);
+			debug = 0;
+			return;
+		}
+	} else {
+		if ((tracefile = fopen(s, "a")) == NULL) {
+			fprintf(stderr, "Can't open %s\n", s);
+			debug = 0;
+			return;
+		}
+	}
+#ifdef O_APPEND
+	if ((flags = fcntl(fileno(tracefile), F_GETFL, 0)) >= 0)
+		fcntl(fileno(tracefile), F_SETFL, flags | O_APPEND);
+#endif
+#ifndef __KLIBC__
+	setlinebuf(tracefile);
+#endif /* __KLIBC__ */
+	fputs("\nTracing started.\n", tracefile);
+}
+#endif /* DEBUG */
diff --git a/src/show.h b/src/show.h
new file mode 100644
index 00000000..d0ccac79
--- /dev/null
+++ b/src/show.h
@@ -0,0 +1,45 @@
+/*-
+ * Copyright (c) 1995
+ *      The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)show.h	1.1 (Berkeley) 5/4/95
+ */
+
+#include <stdarg.h>
+
+#ifdef DEBUG
+union node;
+void showtree(union node *);
+void trace(const char *, ...);
+void tracev(const char *, va_list);
+void trargs(char **);
+void trputc(int);
+void trputs(const char *);
+void opentrace(void);
+#endif
diff --git a/src/system.c b/src/system.c
new file mode 100644
index 00000000..844a6410
--- /dev/null
+++ b/src/system.c
@@ -0,0 +1,199 @@
+/*
+ * Copyright (c) 2004
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef HAVE_ISALPHA
+#define isalnum _isalnum
+#define iscntrl _iscntrl
+#define islower _islower
+#define isspace _isspace
+#define isalpha _isalpha
+#define isdigit _isdigit
+#define isprint _isprint
+#define isupper _isupper
+#define isblank _isblank
+#define isgraph _isgraph
+#define ispunct _ispunct
+#define isxdigit _isxdigit
+#include <ctype.h>
+#undef isalnum
+#undef iscntrl
+#undef islower
+#undef isspace
+#undef isalpha
+#undef isdigit
+#undef isprint
+#undef isupper
+#undef isblank
+#undef isgraph
+#undef ispunct
+#undef isxdigit
+#endif
+
+#include <signal.h>
+#include <string.h>
+
+#include "error.h"
+#include "output.h"
+#include "system.h"
+
+#ifndef HAVE_MEMPCPY
+void *mempcpy(void *dest, const void *src, size_t n)
+{
+	return memcpy(dest, src, n) + n;
+}
+#endif
+
+#ifndef HAVE_STPCPY
+char *stpcpy(char *dest, const char *src)
+{
+	size_t len = strlen(src);
+	dest[len] = 0;
+	return mempcpy(dest, src, len);
+}
+#endif
+
+#ifndef HAVE_STRCHRNUL
+char *strchrnul(const char *s, int c)
+{
+	char *p = strchr(s, c);
+	if (!p)
+		p = (char *)s + strlen(s);
+	return p;
+}
+#endif
+
+#ifndef HAVE_STRSIGNAL
+char *strsignal(int sig)
+{
+	static char buf[19];
+
+	if ((unsigned)sig < NSIG && sys_siglist[sig])
+		return (char *)sys_siglist[sig];
+	fmtstr(buf, sizeof(buf), "Signal %d", sig); 
+	return buf;
+}
+#endif
+
+#ifndef HAVE_BSEARCH
+void *bsearch(const void *key, const void *base, size_t nmemb,
+	      size_t size, int (*cmp)(const void *, const void *))
+{
+	while (nmemb) {
+		size_t mididx = nmemb / 2;
+		const void *midobj = base + mididx * size;
+		int diff = cmp(key, midobj);
+
+		if (diff == 0)
+			return (void *)midobj;
+
+		if (diff > 0) {
+			base = midobj + size;
+			nmemb -= mididx + 1;
+		} else
+			nmemb = mididx;
+	}
+
+	return 0;
+}
+#endif
+
+#ifndef HAVE_SYSCONF
+long sysconf(int name)
+{
+	sh_error("no sysconf for: %d", name);
+}
+#endif
+
+#ifndef HAVE_ISALPHA
+int isalnum(int c) {
+	return _isalnum(c);
+}
+
+
+int iscntrl(int c) {
+	return _iscntrl(c);
+}
+
+
+int islower(int c) {
+	return _islower(c);
+}
+
+
+int isspace(int c) {
+	return _isspace(c);
+}
+
+
+int isalpha(int c) {
+	return _isalpha(c);
+}
+
+
+int isdigit(int c) {
+	return _isdigit(c);
+}
+
+
+int isprint(int c) {
+	return _isprint(c);
+}
+
+
+int isupper(int c) {
+	return _isupper(c);
+}
+
+
+#if HAVE_DECL_ISBLANK
+int isblank(int c) {
+	return _isblank(c);
+}
+#endif
+
+
+int isgraph(int c) {
+	return _isgraph(c);
+}
+
+
+int ispunct(int c) {
+	return _ispunct(c);
+}
+
+
+int isxdigit(int c) {
+	return _isxdigit(c);
+}
+#endif
+
+#if !HAVE_DECL_ISBLANK
+int isblank(int c) {
+	return c == ' ' || c == '\t';
+}
+#endif
diff --git a/src/system.h b/src/system.h
new file mode 100644
index 00000000..007952c5
--- /dev/null
+++ b/src/system.h
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2004
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <limits.h>
+#include <signal.h>
+#include <sys/types.h>
+
+#ifndef SSIZE_MAX
+#define SSIZE_MAX ((ssize_t)((size_t)-1 >> 1))
+#endif
+
+static inline void sigclearmask(void)
+{
+#if defined(HAVE_SIGSETMASK) && \
+    (!defined(__GLIBC__) || \
+     (defined(__GNUC__) && (__GNUC__ * 1000 + __GNUC_MINOR__) >= 4006))
+#ifdef __GLIBC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#endif
+	sigsetmask(0);
+#ifdef __GLIBC__
+#pragma GCC diagnostic pop
+#endif
+#else
+	sigset_t set;
+	sigemptyset(&set);
+	sigprocmask(SIG_SETMASK, &set, 0);
+#endif
+}
+
+#ifndef HAVE_MEMPCPY
+void *mempcpy(void *, const void *, size_t);
+#endif
+
+#ifndef HAVE_STPCPY
+char *stpcpy(char *, const char *);
+#endif
+
+#ifndef HAVE_STRCHRNUL
+char *strchrnul(const char *, int);
+#endif
+
+#ifndef HAVE_STRSIGNAL
+char *strsignal(int);
+#endif
+
+#ifndef HAVE_STRTOD
+static inline double strtod(const char *nptr, char **endptr)
+{
+	*endptr = (char *)nptr;
+	return 0;
+}
+#endif
+
+#ifndef HAVE_STRTOIMAX
+#define strtoimax strtoll
+#endif
+
+#ifndef HAVE_STRTOUMAX
+#define strtoumax strtoull
+#endif
+
+#ifndef HAVE_BSEARCH
+void *bsearch(const void *, const void *, size_t, size_t,
+	      int (*)(const void *, const void *));
+#endif
+
+#ifndef HAVE_KILLPG
+static inline int killpg(pid_t pid, int signal)
+{
+#ifdef DEBUG
+	if (pid < 0)
+		abort();
+#endif
+	return kill(-pid, signal);
+}
+#endif
+
+#ifndef HAVE_SYSCONF
+#define _SC_CLK_TCK 2
+long sysconf(int) __attribute__((__noreturn__));
+#endif
+
+#if !HAVE_DECL_ISBLANK
+int isblank(int c);
+#endif
+
+/*
+ * A trick to suppress uninitialized variable warning without generating any
+ * code
+ */
+#define uninitialized_var(x) x = x
diff --git a/src/trap.c b/src/trap.c
new file mode 100644
index 00000000..cd84814f
--- /dev/null
+++ b/src/trap.c
@@ -0,0 +1,446 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <signal.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "shell.h"
+#include "main.h"
+#include "nodes.h"	/* for other headers */
+#include "eval.h"
+#include "init.h"
+#include "jobs.h"
+#include "show.h"
+#include "options.h"
+#include "syntax.h"
+#include "output.h"
+#include "memalloc.h"
+#include "error.h"
+#include "trap.h"
+#include "mystring.h"
+
+/*
+ * Sigmode records the current value of the signal handlers for the various
+ * modes.  A value of zero means that the current handler is not known.
+ * S_HARD_IGN indicates that the signal was ignored on entry to the shell,
+ */
+
+#define S_DFL 1			/* default signal handling (SIG_DFL) */
+#define S_CATCH 2		/* signal is caught */
+#define S_IGN 3			/* signal is ignored (SIG_IGN) */
+#define S_HARD_IGN 4		/* signal is ignored permenantly */
+#define S_RESET 5		/* temporary - to reset a hard ignored sig */
+
+
+/* trap handler commands */
+MKINIT char *trap[NSIG];
+/* number of non-null traps */
+int trapcnt;
+/* current value of signal */
+char sigmode[NSIG - 1];
+/* indicates specified signal received */
+static char gotsig[NSIG - 1];
+/* last pending signal */
+volatile sig_atomic_t pending_sig;
+/* received SIGCHLD */
+volatile sig_atomic_t gotsigchld;
+
+extern char *signal_names[];
+
+static int decode_signum(const char *);
+
+#ifdef mkinit
+INCLUDE "memalloc.h"
+INCLUDE "trap.h"
+
+INIT {
+	sigmode[SIGCHLD - 1] = S_DFL;
+	setsignal(SIGCHLD);
+}
+
+FORKRESET {
+	char **tp;
+
+	INTOFF;
+	for (tp = trap ; tp < &trap[NSIG] ; tp++) {
+		if (*tp && **tp) {	/* trap not NULL or SIG_IGN */
+			ckfree(*tp);
+			*tp = NULL;
+			if (tp != &trap[0])
+				setsignal(tp - trap);
+		}
+	}
+	trapcnt = 0;
+	INTON;
+}
+#endif
+
+/*
+ * The trap builtin.
+ */
+
+int
+trapcmd(int argc, char **argv)
+{
+	char *action;
+	char **ap;
+	int signo;
+
+	nextopt(nullstr);
+	ap = argptr;
+	if (!*ap) {
+		for (signo = 0 ; signo < NSIG ; signo++) {
+			if (trap[signo] != NULL) {
+				out1fmt(
+					"trap -- %s %s\n",
+					single_quote(trap[signo]),
+					signal_names[signo]
+				);
+			}
+		}
+		return 0;
+	}
+	if (!ap[1] || decode_signum(*ap) >= 0)
+		action = NULL;
+	else
+		action = *ap++;
+	while (*ap) {
+		if ((signo = decode_signal(*ap, 0)) < 0) {
+			outfmt(out2, "trap: %s: bad trap\n", *ap);
+			return 1;
+		}
+		INTOFF;
+		if (action) {
+			if (action[0] == '-' && action[1] == '\0')
+				action = NULL;
+			else {
+				if (*action)
+					trapcnt++;
+				action = savestr(action);
+			}
+		}
+		if (trap[signo]) {
+			if (*trap[signo])
+				trapcnt--;
+			ckfree(trap[signo]);
+		}
+		trap[signo] = action;
+		if (signo != 0)
+			setsignal(signo);
+		INTON;
+		ap++;
+	}
+	return 0;
+}
+
+
+
+/*
+ * Set the signal handler for the specified signal.  The routine figures
+ * out what it should be set to.
+ */
+
+void
+setsignal(int signo)
+{
+	int action;
+	int lvforked;
+	char *t, tsig;
+	struct sigaction act;
+
+	lvforked = vforked;
+
+	if ((t = trap[signo]) == NULL)
+		action = S_DFL;
+	else if (*t != '\0')
+		action = S_CATCH;
+	else
+		action = S_IGN;
+	if (rootshell && action == S_DFL && !lvforked) {
+		switch (signo) {
+		case SIGINT:
+			if (iflag || minusc || sflag == 0)
+				action = S_CATCH;
+			break;
+		case SIGQUIT:
+#ifdef DEBUG
+			if (debug)
+				break;
+#endif
+			/* FALLTHROUGH */
+		case SIGTERM:
+			if (iflag)
+				action = S_IGN;
+			break;
+#if JOBS
+		case SIGTSTP:
+		case SIGTTOU:
+			if (mflag)
+				action = S_IGN;
+			break;
+#endif
+		}
+	}
+
+	if (signo == SIGCHLD)
+		action = S_CATCH;
+
+	t = &sigmode[signo - 1];
+	tsig = *t;
+	if (tsig == 0) {
+		/*
+		 * current setting unknown
+		 */
+		if (sigaction(signo, 0, &act) == -1) {
+			/*
+			 * Pretend it worked; maybe we should give a warning
+			 * here, but other shells don't. We don't alter
+			 * sigmode, so that we retry every time.
+			 */
+			return;
+		}
+		if (act.sa_handler == SIG_IGN) {
+			if (mflag && (signo == SIGTSTP ||
+			     signo == SIGTTIN || signo == SIGTTOU)) {
+				tsig = S_IGN;	/* don't hard ignore these */
+			} else
+				tsig = S_HARD_IGN;
+		} else {
+			tsig = S_RESET;	/* force to be set */
+		}
+	}
+	if (tsig == S_HARD_IGN || tsig == action)
+		return;
+	switch (action) {
+	case S_CATCH:
+		act.sa_handler = onsig;
+		break;
+	case S_IGN:
+		act.sa_handler = SIG_IGN;
+		break;
+	default:
+		act.sa_handler = SIG_DFL;
+	}
+	if (!lvforked)
+		*t = action;
+	act.sa_flags = 0;
+	sigfillset(&act.sa_mask);
+	sigaction(signo, &act, 0);
+}
+
+/*
+ * Ignore a signal.
+ */
+
+void
+ignoresig(int signo)
+{
+	if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN) {
+		signal(signo, SIG_IGN);
+	}
+	if (!vforked)
+		sigmode[signo - 1] = S_HARD_IGN;
+}
+
+
+
+/*
+ * Signal handler.
+ */
+
+void
+onsig(int signo)
+{
+	if (vforked)
+		return;
+
+	if (signo == SIGCHLD) {
+		gotsigchld = 1;
+		if (!trap[SIGCHLD])
+			return;
+	}
+
+	gotsig[signo - 1] = 1;
+	pending_sig = signo;
+
+	if (signo == SIGINT && !trap[SIGINT]) {
+		if (!suppressint)
+			onint();
+		intpending = 1;
+	}
+}
+
+
+
+/*
+ * Called to execute a trap.  Perhaps we should avoid entering new trap
+ * handlers while we are executing a trap handler.
+ */
+
+void dotrap(void)
+{
+	char *p;
+	char *q;
+	int i;
+	int status, last_status;
+
+	if (!pending_sig)
+		return;
+
+	status = savestatus;
+	last_status = status;
+	if (likely(status < 0)) {
+		status = exitstatus;
+		savestatus = status;
+	}
+	pending_sig = 0;
+	barrier();
+
+	for (i = 0, q = gotsig; i < NSIG - 1; i++, q++) {
+		if (!*q)
+			continue;
+
+		if (evalskip) {
+			pending_sig = i + 1;
+			break;
+		}
+
+		*q = 0;
+
+		p = trap[i + 1];
+		if (!p)
+			continue;
+		evalstring(p, 0);
+		if (evalskip != SKIPFUNC)
+			exitstatus = status;
+	}
+
+	savestatus = last_status;
+}
+
+
+
+/*
+ * Controls whether the shell is interactive or not.
+ */
+
+
+void
+setinteractive(int on)
+{
+	static int is_interactive;
+
+	if (++on == is_interactive)
+		return;
+	is_interactive = on;
+	setsignal(SIGINT);
+	setsignal(SIGQUIT);
+	setsignal(SIGTERM);
+}
+
+
+
+/*
+ * Called to exit the shell.
+ */
+
+void
+exitshell(void)
+{
+	struct jmploc loc;
+	char *p;
+
+	savestatus = exitstatus;
+	TRACE(("pid %d, exitshell(%d)\n", getpid(), savestatus));
+	if (setjmp(loc.loc))
+		goto out;
+	handler = &loc;
+	if ((p = trap[0])) {
+		trap[0] = NULL;
+		evalskip = 0;
+		evalstring(p, 0);
+		evalskip = SKIPFUNCDEF;
+	}
+out:
+	exitreset();
+	/*
+	 * Disable job control so that whoever had the foreground before we
+	 * started can get it back.
+	 */
+	if (likely(!setjmp(loc.loc)))
+		setjobctl(0);
+	flushall();
+	_exit(exitstatus);
+	/* NOTREACHED */
+}
+
+static int decode_signum(const char *string)
+{
+	int signo = -1;
+
+	if (is_number(string)) {
+		signo = atoi(string);
+		if (signo >= NSIG)
+			signo = -1;
+	}
+
+	return signo;
+}
+
+int decode_signal(const char *string, int minsig)
+{
+	int signo;
+
+	signo = decode_signum(string);
+	if (signo >= 0)
+		return signo;
+
+	for (signo = minsig; signo < NSIG; signo++) {
+		if (!strcasecmp(string, signal_names[signo])) {
+			return signo;
+		}
+	}
+
+	return -1;
+}
+
+void sigblockall(sigset_t *oldmask)
+{
+	sigset_t mask;
+
+	sigfillset(&mask);
+	sigprocmask(SIG_SETMASK, &mask, oldmask);
+}
diff --git a/src/trap.h b/src/trap.h
new file mode 100644
index 00000000..beaf6605
--- /dev/null
+++ b/src/trap.h
@@ -0,0 +1,57 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)trap.h	8.3 (Berkeley) 6/5/95
+ */
+
+#include <signal.h>
+
+extern int trapcnt;
+extern char sigmode[];
+extern volatile sig_atomic_t pending_sig;
+extern volatile sig_atomic_t gotsigchld;
+
+int trapcmd(int, char **);
+void setsignal(int);
+void ignoresig(int);
+void onsig(int);
+void dotrap(void);
+void setinteractive(int);
+void exitshell(void) __attribute__((__noreturn__));
+int decode_signal(const char *, int);
+void sigblockall(sigset_t *oldmask);
+
+static inline int have_traps(void)
+{
+	return trapcnt;
+}
diff --git a/src/var.c b/src/var.c
new file mode 100644
index 00000000..ef9c2bde
--- /dev/null
+++ b/src/var.c
@@ -0,0 +1,674 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+
+/*
+ * Shell variables.
+ */
+
+#include "shell.h"
+#include "output.h"
+#include "expand.h"
+#include "nodes.h"	/* for other headers */
+#include "exec.h"
+#include "syntax.h"
+#include "options.h"
+#include "mail.h"
+#include "var.h"
+#include "memalloc.h"
+#include "error.h"
+#include "mystring.h"
+#include "parser.h"
+#include "show.h"
+#ifndef SMALL
+#include "myhistedit.h"
+#endif
+#include "system.h"
+
+
+#define VTABSIZE 39
+
+
+struct localvar_list {
+	struct localvar_list *next;
+	struct localvar *lv;
+};
+
+MKINIT struct localvar_list *localvar_stack;
+
+const char defpathvar[] =
+	"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin";
+char defifsvar[] = "IFS= \t\n";
+MKINIT char defoptindvar[] = "OPTIND=1";
+
+int lineno;
+char linenovar[sizeof("LINENO=")+sizeof(int)*CHAR_BIT/3+1] = "LINENO=";
+
+/* Some macros in var.h depend on the order, add new variables to the end. */
+struct var varinit[] = {
+#if ATTY
+	{ 0,	VSTRFIXED|VTEXTFIXED|VUNSET,	"ATTY\0",	0 },
+#endif
+	{ 0,	VSTRFIXED|VTEXTFIXED,		defifsvar,	0 },
+	{ 0,	VSTRFIXED|VTEXTFIXED|VUNSET,	"MAIL\0",	changemail },
+	{ 0,	VSTRFIXED|VTEXTFIXED|VUNSET,	"MAILPATH\0",	changemail },
+	{ 0,	VSTRFIXED|VTEXTFIXED,		defpathvar,	changepath },
+	{ 0,	VSTRFIXED|VTEXTFIXED,		"PS1=$ ",	0 },
+	{ 0,	VSTRFIXED|VTEXTFIXED,		"PS2=> ",	0 },
+	{ 0,	VSTRFIXED|VTEXTFIXED,		"PS4=+ ",	0 },
+	{ 0,	VSTRFIXED|VTEXTFIXED,		defoptindvar,	getoptsreset },
+#ifdef WITH_LINENO
+	{ 0,	VSTRFIXED|VTEXTFIXED,		linenovar,	0 },
+#endif
+#ifndef SMALL
+	{ 0,	VSTRFIXED|VTEXTFIXED|VUNSET,	"TERM\0",	0 },
+	{ 0,	VSTRFIXED|VTEXTFIXED|VUNSET,	"HISTSIZE\0",	sethistsize },
+#endif
+};
+
+STATIC struct var *vartab[VTABSIZE];
+
+STATIC struct var **hashvar(const char *);
+STATIC int vpcmp(const void *, const void *);
+STATIC struct var **findvar(struct var **, const char *);
+
+/*
+ * Initialize the varable symbol tables and import the environment
+ */
+
+#ifdef mkinit
+INCLUDE <unistd.h>
+INCLUDE <sys/types.h>
+INCLUDE <sys/stat.h>
+INCLUDE "cd.h"
+INCLUDE "output.h"
+INCLUDE "var.h"
+MKINIT char **environ;
+INIT {
+	char **envp;
+	static char ppid[32] = "PPID=";
+	const char *p;
+	struct stat64 st1, st2;
+
+	initvar();
+	for (envp = environ ; *envp ; envp++) {
+		p = endofname(*envp);
+		if (p != *envp && *p == '=') {
+			setvareq(*envp, VEXPORT|VTEXTFIXED);
+		}
+	}
+
+	setvareq(defifsvar, VTEXTFIXED);
+	setvareq(defoptindvar, VTEXTFIXED);
+
+	fmtstr(ppid + 5, sizeof(ppid) - 5, "%ld", (long) getppid());
+	setvareq(ppid, VTEXTFIXED);
+
+	p = lookupvar("PWD");
+	if (p)
+		if (*p != '/' || stat64(p, &st1) || stat64(".", &st2) ||
+		    st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
+			p = 0;
+	setpwd(p, 0);
+}
+
+RESET {
+	unwindlocalvars(0);
+}
+#endif
+
+
+/*
+ * This routine initializes the builtin variables.  It is called when the
+ * shell is initialized.
+ */
+
+void
+initvar(void)
+{
+	struct var *vp;
+	struct var *end;
+	struct var **vpp;
+
+	vp = varinit;
+	end = vp + sizeof(varinit) / sizeof(varinit[0]);
+	do {
+		vpp = hashvar(vp->text);
+		vp->next = *vpp;
+		*vpp = vp;
+	} while (++vp < end);
+	/*
+	 * PS1 depends on uid
+	 */
+	if (!geteuid())
+		vps1.text = "PS1=# ";
+}
+
+/*
+ * Set the value of a variable.  The flags argument is ored with the
+ * flags of the variable.  If val is NULL, the variable is unset.
+ */
+
+struct var *setvar(const char *name, const char *val, int flags)
+{
+	char *p, *q;
+	size_t namelen;
+	char *nameeq;
+	size_t vallen;
+	struct var *vp;
+
+	q = endofname(name);
+	p = strchrnul(q, '=');
+	namelen = p - name;
+	if (!namelen || p != q)
+		sh_error("%.*s: bad variable name", namelen, name);
+	vallen = 0;
+	if (val == NULL) {
+		flags |= VUNSET;
+	} else {
+		vallen = strlen(val);
+	}
+	INTOFF;
+	p = mempcpy(nameeq = ckmalloc(namelen + vallen + 2), name, namelen);
+	if (val) {
+		*p++ = '=';
+		p = mempcpy(p, val, vallen);
+	}
+	*p = '\0';
+	vp = setvareq(nameeq, flags | VNOSAVE);
+	INTON;
+
+	return vp;
+}
+
+/*
+ * Set the given integer as the value of a variable.  The flags argument is
+ * ored with the flags of the variable.
+ */
+
+intmax_t setvarint(const char *name, intmax_t val, int flags)
+{
+	int len = max_int_length(sizeof(val));
+	char buf[len];
+
+	fmtstr(buf, len, "%" PRIdMAX, val);
+	setvar(name, buf, flags);
+	return val;
+}
+
+
+
+/*
+ * Same as setvar except that the variable and value are passed in
+ * the first argument as name=value.  Since the first argument will
+ * be actually stored in the table, it should not be a string that
+ * will go away.
+ * Called with interrupts off.
+ */
+
+struct var *setvareq(char *s, int flags)
+{
+	struct var *vp, **vpp;
+
+	vpp = hashvar(s);
+	flags |= (VEXPORT & (((unsigned) (1 - aflag)) - 1));
+	vpp = findvar(vpp, s);
+	vp = *vpp;
+	if (vp) {
+		if (vp->flags & VREADONLY) {
+			const char *n;
+
+			if (flags & VNOSAVE)
+				free(s);
+			n = vp->text;
+			sh_error("%.*s: is read only", strchrnul(n, '=') - n,
+				 n);
+		}
+
+		if (flags & VNOSET)
+			goto out;
+
+		if (vp->func && (flags & VNOFUNC) == 0)
+			(*vp->func)(strchrnul(s, '=') + 1);
+
+		if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
+			ckfree(vp->text);
+
+		if (((flags & (VEXPORT|VREADONLY|VSTRFIXED|VUNSET)) |
+		     (vp->flags & VSTRFIXED)) == VUNSET) {
+			*vpp = vp->next;
+			ckfree(vp);
+out_free:
+			if ((flags & (VTEXTFIXED|VSTACK|VNOSAVE)) == VNOSAVE)
+				ckfree(s);
+			goto out;
+		}
+
+		flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET);
+	} else {
+		if (flags & VNOSET)
+			goto out;
+		if ((flags & (VEXPORT|VREADONLY|VSTRFIXED|VUNSET)) == VUNSET)
+			goto out_free;
+		/* not found */
+		vp = ckmalloc(sizeof (*vp));
+		vp->next = *vpp;
+		vp->func = NULL;
+		*vpp = vp;
+	}
+	if (!(flags & (VTEXTFIXED|VSTACK|VNOSAVE)))
+		s = savestr(s);
+	vp->text = s;
+	vp->flags = flags;
+
+out:
+	return vp;
+}
+
+/*
+ * Find the value of a variable.  Returns NULL if not set.
+ */
+
+char *
+lookupvar(const char *name)
+{
+	struct var *v;
+
+	if ((v = *findvar(hashvar(name), name)) && !(v->flags & VUNSET)) {
+#ifdef WITH_LINENO
+		if (v == &vlineno && v->text == linenovar) {
+			fmtstr(linenovar+7, sizeof(linenovar)-7, "%d", lineno);
+		}
+#endif
+		return strchrnul(v->text, '=') + 1;
+	}
+	return NULL;
+}
+
+intmax_t lookupvarint(const char *name)
+{
+	return atomax(lookupvar(name) ?: nullstr, 0);
+}
+
+
+
+/*
+ * Generate a list of variables satisfying the given conditions.
+ */
+
+char **
+listvars(int on, int off, char ***end)
+{
+	struct var **vpp;
+	struct var *vp;
+	char **ep;
+	int mask;
+
+	STARTSTACKSTR(ep);
+	vpp = vartab;
+	mask = on | off;
+	do {
+		for (vp = *vpp ; vp ; vp = vp->next)
+			if ((vp->flags & mask) == on) {
+				if (ep == stackstrend())
+					ep = growstackstr();
+				*ep++ = (char *) vp->text;
+			}
+	} while (++vpp < vartab + VTABSIZE);
+	if (ep == stackstrend())
+		ep = growstackstr();
+	if (end)
+		*end = ep;
+	*ep++ = NULL;
+	return grabstackstr(ep);
+}
+
+
+
+/*
+ * POSIX requires that 'set' (but not export or readonly) output the
+ * variables in lexicographic order - by the locale's collating order (sigh).
+ * Maybe we could keep them in an ordered balanced binary tree
+ * instead of hashed lists.
+ * For now just roll 'em through qsort for printing...
+ */
+
+int
+showvars(const char *prefix, int on, int off)
+{
+	const char *sep;
+	char **ep, **epend;
+
+	ep = listvars(on, off, &epend);
+	qsort(ep, epend - ep, sizeof(char *), vpcmp);
+
+	sep = *prefix ? spcstr : prefix;
+
+	for (; ep < epend; ep++) {
+		const char *p;
+		const char *q;
+
+		p = strchrnul(*ep, '=');
+		q = nullstr;
+		if (*p)
+			q = single_quote(++p);
+
+		out1fmt("%s%s%.*s%s\n", prefix, sep, (int)(p - *ep), *ep, q);
+	}
+
+	return 0;
+}
+
+
+
+/*
+ * The export and readonly commands.
+ */
+
+int
+exportcmd(int argc, char **argv)
+{
+	struct var *vp;
+	char *name;
+	const char *p;
+	char **aptr;
+	int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
+	int notp;
+
+	notp = nextopt("p") - 'p';
+	if (notp && ((name = *(aptr = argptr)))) {
+		do {
+			if ((p = strchr(name, '=')) != NULL) {
+				p++;
+			} else {
+				if ((vp = *findvar(hashvar(name), name))) {
+					vp->flags |= flag;
+					continue;
+				}
+			}
+			setvar(name, p, flag);
+		} while ((name = *++aptr) != NULL);
+	} else {
+		showvars(argv[0], flag, 0);
+	}
+	return 0;
+}
+
+
+/*
+ * The "local" command.
+ */
+
+int
+localcmd(int argc, char **argv)
+{
+	char *name;
+
+	if (!localvar_stack)
+		sh_error("not in a function");
+
+	argv = argptr;
+	while ((name = *argv++) != NULL) {
+		mklocal(name, 0);
+	}
+	return 0;
+}
+
+
+/*
+ * Make a variable a local variable.  When a variable is made local, it's
+ * value and flags are saved in a localvar structure.  The saved values
+ * will be restored when the shell function returns.  We handle the name
+ * "-" as a special case.
+ */
+
+void mklocal(char *name, int flags)
+{
+	struct localvar *lvp;
+	struct var **vpp;
+	struct var *vp;
+
+	INTOFF;
+	lvp = ckmalloc(sizeof (struct localvar));
+	if (name[0] == '-' && name[1] == '\0') {
+		char *p;
+		p = ckmalloc(sizeof(optlist));
+		lvp->text = memcpy(p, optlist, sizeof(optlist));
+		vp = NULL;
+	} else {
+		char *eq;
+
+		vpp = hashvar(name);
+		vp = *findvar(vpp, name);
+		eq = strchr(name, '=');
+		if (vp == NULL) {
+			if (eq)
+				vp = setvareq(name, VSTRFIXED | flags);
+			else
+				vp = setvar(name, NULL, VSTRFIXED | flags);
+			lvp->flags = VUNSET;
+		} else {
+			lvp->text = vp->text;
+			lvp->flags = vp->flags;
+			vp->flags |= VSTRFIXED|VTEXTFIXED;
+			if (eq)
+				setvareq(name, flags);
+		}
+	}
+	lvp->vp = vp;
+	lvp->next = localvar_stack->lv;
+	localvar_stack->lv = lvp;
+	INTON;
+}
+
+
+/*
+ * Called after a function returns.
+ * Interrupts must be off.
+ */
+
+static void
+poplocalvars(void)
+{
+	struct localvar_list *ll;
+	struct localvar *lvp, *next;
+	struct var *vp;
+
+	INTOFF;
+	ll = localvar_stack;
+	localvar_stack = ll->next;
+
+	next = ll->lv;
+	ckfree(ll);
+
+	while ((lvp = next) != NULL) {
+		next = lvp->next;
+		vp = lvp->vp;
+		TRACE(("poplocalvar %s\n", vp ? vp->text : "-"));
+		if (vp == NULL) {	/* $- saved */
+			memcpy(optlist, lvp->text, sizeof(optlist));
+			ckfree(lvp->text);
+			optschanged();
+		} else if (lvp->flags == VUNSET) {
+			vp->flags &= ~(VSTRFIXED|VREADONLY);
+			unsetvar(vp->text);
+		} else {
+			if (vp->func)
+				(*vp->func)(strchrnul(lvp->text, '=') + 1);
+			if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
+				ckfree(vp->text);
+			vp->flags = lvp->flags;
+			vp->text = lvp->text;
+		}
+		ckfree(lvp);
+	}
+	INTON;
+}
+
+
+/*
+ * Create a new localvar environment.
+ */
+struct localvar_list *pushlocalvars(int push)
+{
+	struct localvar_list *ll;
+	struct localvar_list *top;
+
+	top = localvar_stack;
+	if (!push)
+		goto out;
+
+	INTOFF;
+	ll = ckmalloc(sizeof(*ll));
+	ll->lv = NULL;
+	ll->next = top;
+	localvar_stack = ll;
+	INTON;
+
+out:
+	return top;
+}
+
+
+void unwindlocalvars(struct localvar_list *stop)
+{
+	while (localvar_stack != stop)
+		poplocalvars();
+}
+
+
+/*
+ * The unset builtin command.  We unset the function before we unset the
+ * variable to allow a function to be unset when there is a readonly variable
+ * with the same name.
+ */
+
+int
+unsetcmd(int argc, char **argv)
+{
+	char **ap;
+	int i;
+	int flag = 0;
+
+	while ((i = nextopt("vf")) != '\0') {
+		flag = i;
+	}
+
+	for (ap = argptr; *ap ; ap++) {
+		if (flag != 'f') {
+			unsetvar(*ap);
+			continue;
+		}
+		if (flag != 'v')
+			unsetfunc(*ap);
+	}
+	return 0;
+}
+
+
+/*
+ * Unset the specified variable.
+ */
+
+void unsetvar(const char *s)
+{
+	setvar(s, 0, 0);
+}
+
+
+
+/*
+ * Find the appropriate entry in the hash table from the name.
+ */
+
+STATIC struct var **
+hashvar(const char *p)
+{
+	unsigned int hashval;
+
+	hashval = ((unsigned char) *p) << 4;
+	while (*p && *p != '=')
+		hashval += (unsigned char) *p++;
+	return &vartab[hashval % VTABSIZE];
+}
+
+
+
+/*
+ * Compares two strings up to the first = or '\0'.  The first
+ * string must be terminated by '='; the second may be terminated by
+ * either '=' or '\0'.
+ */
+
+int
+varcmp(const char *p, const char *q)
+{
+	int c, d;
+
+	while ((c = *p) == (d = *q)) {
+		if (!c || c == '=')
+			goto out;
+		p++;
+		q++;
+	}
+	if (c == '=')
+		c = 0;
+	if (d == '=')
+		d = 0;
+out:
+	return c - d;
+}
+
+STATIC int
+vpcmp(const void *a, const void *b)
+{
+	return varcmp(*(const char **)a, *(const char **)b);
+}
+
+STATIC struct var **
+findvar(struct var **vpp, const char *name)
+{
+	for (; *vpp; vpp = &(*vpp)->next) {
+		if (varequal((*vpp)->text, name)) {
+			break;
+		}
+	}
+	return vpp;
+}
diff --git a/src/var.h b/src/var.h
new file mode 100644
index 00000000..aa7575a7
--- /dev/null
+++ b/src/var.h
@@ -0,0 +1,169 @@
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1997-2005
+ *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)var.h	8.2 (Berkeley) 5/4/95
+ */
+
+#include <inttypes.h>
+
+/*
+ * Shell variables.
+ */
+
+/* flags */
+#define VEXPORT		0x01	/* variable is exported */
+#define VREADONLY	0x02	/* variable cannot be modified */
+#define VSTRFIXED	0x04	/* variable struct is statically allocated */
+#define VTEXTFIXED	0x08	/* text is statically allocated */
+#define VSTACK		0x10	/* text is allocated on the stack */
+#define VUNSET		0x20	/* the variable is not set */
+#define VNOFUNC		0x40	/* don't call the callback function */
+#define VNOSET		0x80	/* do not set variable - just readonly test */
+#define VNOSAVE		0x100	/* when text is on the heap before setvareq */
+
+
+struct var {
+	struct var *next;		/* next entry in hash list */
+	int flags;			/* flags are defined above */
+	const char *text;		/* name=value */
+	void (*func)(const char *);
+					/* function to be called when  */
+					/* the variable gets set/unset */
+};
+
+
+struct localvar {
+	struct localvar *next;		/* next local variable in list */
+	struct var *vp;			/* the variable that was made local */
+	int flags;			/* saved flags */
+	const char *text;		/* saved text */
+};
+
+struct localvar_list;
+
+
+extern struct localvar *localvars;
+extern struct var varinit[];
+
+#if ATTY
+#define vatty varinit[0]
+#define vifs varinit[1]
+#else
+#define vifs varinit[0]
+#endif
+#define vmail (&vifs)[1]
+#define vmpath (&vmail)[1]
+#define vpath (&vmpath)[1]
+#define vps1 (&vpath)[1]
+#define vps2 (&vps1)[1]
+#define vps4 (&vps2)[1]
+#define voptind (&vps4)[1]
+#ifdef WITH_LINENO
+#define vlineno (&voptind)[1]
+#endif
+#ifndef SMALL
+#ifdef WITH_LINENO
+#define vterm (&vlineno)[1]
+#else
+#define vterm (&voptind)[1]
+#endif
+#define vhistsize (&vterm)[1]
+#endif
+
+extern char defifsvar[];
+#define defifs (defifsvar + 4)
+extern const char defpathvar[];
+#define defpath (defpathvar + 36)
+
+extern int lineno;
+extern char linenovar[];
+
+/*
+ * The following macros access the values of the above variables.
+ * They have to skip over the name.  They return the null string
+ * for unset variables.
+ */
+
+#define ifsval()	(vifs.text + 4)
+#define ifsset()	((vifs.flags & VUNSET) == 0)
+#define mailval()	(vmail.text + 5)
+#define mpathval()	(vmpath.text + 9)
+#define pathval()	(vpath.text + 5)
+#define ps1val()	(vps1.text + 4)
+#define ps2val()	(vps2.text + 4)
+#define ps4val()	(vps4.text + 4)
+#define optindval()	(voptind.text + 7)
+#define linenoval()	(vlineno.text + 7)
+#ifndef SMALL
+#define histsizeval()	(vhistsize.text + 9)
+#define termval()	(vterm.text + 5)
+#endif
+
+#if ATTY
+#define attyset()	((vatty.flags & VUNSET) == 0)
+#endif
+#define mpathset()	((vmpath.flags & VUNSET) == 0)
+
+void initvar(void);
+struct var *setvar(const char *name, const char *val, int flags);
+intmax_t setvarint(const char *, intmax_t, int);
+struct var *setvareq(char *s, int flags);
+struct strlist;
+char *lookupvar(const char *);
+intmax_t lookupvarint(const char *);
+char **listvars(int, int, char ***);
+#define environment() listvars(VEXPORT, VUNSET, 0)
+int showvars(const char *, int, int);
+int exportcmd(int, char **);
+int localcmd(int, char **);
+void mklocal(char *name, int flags);
+struct localvar_list *pushlocalvars(int push);
+void unwindlocalvars(struct localvar_list *stop);
+int unsetcmd(int, char **);
+void unsetvar(const char *);
+int varcmp(const char *, const char *);
+
+static inline int varequal(const char *a, const char *b) {
+	return !varcmp(a, b);
+}
+
+/*
+ * Search the environment of a builtin command.
+ */
+
+static inline char *bltinlookup(const char *name)
+{
+	return lookupvar(name);
+}
+
+