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# 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
	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
	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
	args	  nodeptr		# for var in args
	body	  nodeptr		# do body; done
	var	  string		# the for variable

NCASE ncase			# a case statement
	type	  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 narg			# define a function.  The "next" field contains
				# the body of the function.

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
cea81b489819f753451c1ad2fe435f148&follow=1'>eval: Restore input files in evalcommandHerbert Xu When evalcommand invokes a command that modifies parsefile and then bails out without popping the file, we need to ensure the input file is restored so that the shell can continue to execute. Reported-by: Martijn Dekker <martijn@inlv.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 2018-04-19eval: Reap zombies after built-in commands and functionsHerbert Xu Currently dash does not reap dead children after built-in commands or functions. This means that if you construct a loop consisting of solely built-in commands and functions, then zombies can hang around indefinitely. This patch fixes this by reaping when necessary after each built-in command and function. Reported-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 2018-04-19redir: Fix typo in noclobber codeHerbert Xu The noclobber code has a typo in it that causes it to fail. This patch fixes it. Reported-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 2018-04-19expand: Fix glibc glob(3) supportHerbert Xu It's been a while since we disabled glob(3) support by default. It appears to be working now, however, we have to change our code to detect the no-match case correctly. In particular, we need to test for GLOB_NOMAGIC | GLOB_NOCHECK instead of GLOB_MAGCHAR. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 2018-04-02expand: Fix buffer overflow in expandmetaHerbert Xu The native version of expandmeta allocates a buffer that may be overrun for two reasons. First of all the size is 1 byte too small but this is normally hidden because the minimum size is rounded up to 2048 bytes. Secondly, if the directory level is deep enough, any buffer can be overrun. This patch fixes both problems by calling realloc when necessary. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 2018-04-02builtin: Move echo space/nl handling into print_escape_strHerbert Xu Currently echocmd uses print_escape_str to do everything apart from printing the spaces/newlines separating its arguments. This patch moves the actual printing into print_escape_str as well using the format parameter. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 2018-04-02builtin: Fix echo performance regressionHerbert Xu The commit d6c0e1e2ffbf7913ab69d51cc794d48d41c8fcb1 ("[BUILTIN] Handle embedded NULs correctly in printf") caused a performance regression in the echo built-in because every echo call now goes through the printf %b slow path where the string is always printed twice to ensure the space padding is correct in the presence of NUL characters. In fact this regression applies to printf %b as well. This is easily fixed by making printf %b take the fast path when no precision/field width modifiers are present. This patch also changes the second strchurnul call to strspn which generates slightly better code. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 2018-04-02expand: Fix ghost fields with unquoted $@/$*Herbert Xu Harald van Dijk <harald@gigawatt.nl> wrote: > On 22/03/2018 22:38, Martijn Dekker wrote: >> Op 22-03-18 om 20:28 schreef Harald van Dijk: >>> On 22/03/2018 03:40, Martijn Dekker wrote: >>>> This patch fixes the bug that, given no positional parameters, unquoted >>>> $@ and $* incorrectly generate one empty field (they should generate no >>>> fields). Apparently that was a side effect of the above. >>> >>> This seems weird though. If you want to remove the recording of empty >>> regions because they are pointless, then how does removing them fix a >>> bug? Doesn't this show that empty regions do have an effect? Perhaps >>> they're not supposed to have any effect, perhaps it's a specific >>> combination of empty regions and something else that triggers some bug, >>> and perhaps that combination can no longer occur with your patch. >> >> The latter is my guess, but I haven't had time to investigate it. > > Looking into it again: > > When IFS is set to an empty string, sepc is set to '\0' in varvalue(). > This then causes *quotedp to be set to true, meaning evalvar()'s quoted > variable is turned on. quoted is then passed to recordregion() as the > nulonly parameter. > > ifsp->nulonly has a bigger effect than merely selecting whether to use > $IFS or whether to only split on null bytes: in ifsbreakup(), nulonly > also causes string termination to be suppressed. That's correct: that > special treatment is required to preserve empty fields in "$@" > expansion. But it should *only* be used when $@ is quoted: ifsbreakup() > takes nulonly from the last IFS region, even if it's empty, so having an > additional zero-length region with nulonly enabled causes confusion. > > Passing quoted by value to varvalue() and not attempting to modify it > should therefore, and in my quick testing does, also work to fix the > original $@ bug. You're right. The proper fix to this is to ensure that nulonly is not set in varvalue for $*. It should only be set for $@ when it's inside double quotes. In fact there is another bug while we're playing with $@/$*. When IFS is set to a non-whitespace character such as :, $* outside quotes won't remove empty fields as it should. This patch fixes both problems. Reported-by: Martijn Dekker <martijn@inlv.org> Suggested-by: Harald van Dijk <harald@gigawatt.nl> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 2018-04-02parser: Allow newlines within parameter substitutionHerbert Xu On Fri, Mar 16, 2018 at 11:27:22AM +0800, Herbert Xu wrote: > On Thu, Mar 15, 2018 at 10:49:15PM +0100, Harald van Dijk wrote: > > > > Okay, it can be trivially modified to something that does work in other > > shells (even if it were actually executed), but gets rejected at parse time > > by dash: > > > > if false; then > > : ${$+ > > } > > fi > > That's just a bug in dash's parser with ${} in general, because > it bombs out without the if clause too: > > : ${$+ > } This patch fixes the parsing of newlines with parameter substitution. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 2018-04-02expand: Fix bugs with words connected to the right of $@Herbert Xu On Sun, Mar 04, 2018 at 12:44:59PM +0100, Harald van Dijk wrote: > > command: set -- a ""; space=" "; printf "<%s>" "$@"$space > bash: <a><> > dash 0.5.8: <a>< > > dash 0.5.9.1: <a>< > > dash patched: <a><> This is actually composed of two bugs. First of all our tracking of quotemark is wrong so anything after "$@" becomes quoted. Once we fix that then the problem is that the first space character after "$@" is not recognised as an IFS. This patch fixes both. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 2018-03-25Revert "[BUILTIN] Remove unnecessary restoration of format string in printf"Herbert Xu This reverts commit 7bb413255368e94395237d789f522891093c5774. The commit breaks printf with more than argument. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 2018-03-22parser: Fix backquote support in here-document EOF markHerbert Xu