jilles 74d9b02bb0 sh: Don't do optimized command substitution if expansions have side effects. ... Before considering to execute a command substitution in the same process, check if any of the expansions may have a side effect; if so, execute it in a new process just like happens if it is not a single simple command. Although the check happens at run time, it is a static check that does not depend on current state. It is triggered by: - expanding $! (which may cause the job to be remembered) - ${var=value} default value assignment - assignment operators in arithmetic - parameter substitutions in arithmetic except ${#param}, $$, $# and $? - command substitutions in arithmetic This means that $((v+1)) does not prevent optimized command substitution, whereas $(($v+1)) does, because $v might expand to something containing assignment operators. Scripts should not depend on these exact details for correctness. It is also imaginable to have the shell fork if and when a side effect is encountered or to create a new temporary namespace for variables. Due to the $! change, the construct $(jobs $!) no longer works. The value of $! should be stored in a variable outside command substitution first.		2010-12-28 21:27:08 +00:00
..
bltin	sh: Add kill builtin.	2010-12-21 22:47:34 +00:00
funcs	sh: Update the suspend example for the change of the job control flag	2010-11-13 22:20:46 +00:00
alias.c	sh: Add a function to print warnings (with command name and newline).	2010-12-21 20:47:06 +00:00
alias.h	sh: Constify various strings.	2009-12-24 18:41:14 +00:00
arith_lex.l	sh: arith: Disallow decimal constants starting with 0 (containing 8 or 9).	2010-12-18 23:03:51 +00:00
arith.h	sh: Constify various strings.	2009-12-24 18:41:14 +00:00
arith.y	sh: Use stalloc for arith variable names.	2010-04-25 20:43:19 +00:00
builtins.def	sh: Add kill builtin.	2010-12-21 22:47:34 +00:00
cd.c	sh: Add a function to print warnings (with command name and newline).	2010-12-21 20:47:06 +00:00
cd.h	sh: On startup of the shell, use PWD from the environment if it is valid.	2010-04-17 14:35:46 +00:00
error.c	sh: Add a function to print warnings (with command name and newline).	2010-12-21 20:47:06 +00:00
error.h	sh: Add a function to print warnings (with command name and newline).	2010-12-21 20:47:06 +00:00
eval.c	sh: Don't do optimized command substitution if expansions have side effects.	2010-12-28 21:27:08 +00:00
eval.h	sh: Various warning fixes (from WARNS=6 NO_WERROR=1):	2009-12-27 18:04:05 +00:00
exec.c	sh: Allow arbitrary large numbers in CHECKSTRSPACE.	2010-12-26 13:25:47 +00:00
exec.h	sh: Improve the command builtin:	2010-03-06 16:57:53 +00:00
expand.c	sh: Don't do optimized command substitution if expansions have side effects.	2010-12-28 21:27:08 +00:00
expand.h	sh: Don't do optimized command substitution if expansions have side effects.	2010-12-28 21:27:08 +00:00
histedit.c	sh: Code size optimizations to "stack string" memory allocation:	2010-11-23 22:17:39 +00:00
init.h
input.c	In the spirit of r90111, depend on c89 and remove the "STATIC" macro	2010-10-13 22:18:03 +00:00
input.h	sh: Constify various strings.	2009-12-24 18:41:14 +00:00
jobs.c	sh: Add kill builtin.	2010-12-21 22:47:34 +00:00
jobs.h	sh: Forget about terminated background processes sooner.	2010-06-29 22:37:45 +00:00
mail.c	Consistently use "STATIC" for all functions in order to be able to set	2010-10-13 04:01:01 +00:00
mail.h
main.c	sh: Code size optimizations to buffered output.	2010-11-20 14:14:52 +00:00
main.h	sh: Do not run callers' exception handlers in subshells.	2009-12-25 20:21:35 +00:00
Makefile	sh: Add kill builtin.	2010-12-21 22:47:34 +00:00
memalloc.c	sh: Simplify "stack string" code slightly.	2010-12-27 22:18:27 +00:00
memalloc.h	sh: Simplify "stack string" code slightly.	2010-12-27 22:18:27 +00:00
miscbltin.c	sh: Code size optimizations to "stack string" memory allocation:	2010-11-23 22:17:39 +00:00
mkbuiltins	sh: Various warning fixes (from WARNS=6 NO_WERROR=1):	2009-12-27 18:04:05 +00:00
mkinit.c	sh: Various warning fixes (from WARNS=6 NO_WERROR=1):	2009-12-27 18:04:05 +00:00
mknodes.c	sh: Fix crash with empty functions (f() { }) introduced in r196483	2009-08-28 22:41:25 +00:00
mksyntax.c	sh: Remove the check that alpha/name/in_name chars are not CTL* bytes.	2010-11-20 14:30:28 +00:00
mktokens
myhistedit.h	sh: Pass TERM changes to libedit.	2010-06-02 19:16:58 +00:00
mystring.c	sh: Various warning fixes (from WARNS=6 NO_WERROR=1):	2009-12-27 18:04:05 +00:00
mystring.h
nodes.c.pat	In the spirit of r90111, depend on c89 and remove the "STATIC" macro	2010-10-13 22:18:03 +00:00
nodetypes
options.c	sh: Code size optimizations to buffered output.	2010-11-20 14:14:52 +00:00
options.h	sh: Various warning fixes (from WARNS=6 NO_WERROR=1):	2009-12-27 18:04:05 +00:00
output.c	sh: Use vsnprintf() rather than crafting our own in fmtstr().	2010-12-11 17:47:27 +00:00
output.h	sh: Code size optimizations to buffered output.	2010-11-20 14:14:52 +00:00
parser.c	sh: Allow arbitrary large numbers in CHECKSTRSPACE.	2010-12-26 13:25:47 +00:00
parser.h	sh: Do IFS splitting on word in ${v+word} and ${v-word}.	2010-10-29 13:42:18 +00:00
redir.c	sh: Check whether dup2 was successful for >&FD and <&FD.	2010-10-24 20:09:49 +00:00
redir.h
sh.1	sh(1): Explain why it is a bad idea to use aliases in scripts.	2010-12-21 22:48:56 +00:00
shell.h	In the spirit of r90111, depend on c89 and remove the "STATIC" macro	2010-10-13 22:18:03 +00:00
show.c	In the spirit of r90111, depend on c89 and remove the "STATIC" macro	2010-10-13 22:18:03 +00:00
show.h	sh: Constify various strings.	2009-12-24 18:41:14 +00:00
TOUR	Correct assorted grammos and typos.	2006-04-16 11:54:01 +00:00
trap.c	sh: Add a function to print warnings (with command name and newline).	2010-12-21 20:47:06 +00:00
trap.h	sh: Add some __dead2 to indicate functions that do not return.	2009-12-24 20:55:14 +00:00
var.c	sh: Code size optimizations to buffered output.	2010-11-20 14:14:52 +00:00
var.h	sh: Pass TERM changes to libedit.	2010-06-02 19:16:58 +00:00