1 files changed, 1139 insertions, 0 deletions

diff --git a/bin/dash/src/eval.c b/bin/dash/src/eval.c
new file mode 100644
index 00000000..d4190f95
--- /dev/null
+++ b/bin/dash/src/eval.c
@@ -0,0 +1,1139 @@
+/*-
+ * 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:
+		evalfn = evalcommand;
+checkexit:
+		checkexit = ~flags & EV_TESTED;
+		goto calleval;
+	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 (eflag && 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;
+}