Commit Graph

61 Commits

Author SHA1 Message Date
Bryan Drewery
a59f817491 sh: Fix the trap builtin to be POSIX-compliant for 'trap exit SIG' and 'trap n n...'.
The parser considered 'trap exit INT' to reset the default for both EXIT and
INT. This beahvior is not POSIX compliant. This was avoided if a value was
specified for 'exit', but then disallows exiting with the signal received. A
possible workaround is using ' exit'.

However POSIX does allow this type of behavior if the parameters are all
integers. Fix the handling for this and clarify its support in the manpage
since it is specifically allowed by POSIX.

Differential Revision:	https://reviews.freebsd.org/D2325
Reviewed by:	jilles
MFC after:	2 weeks
2015-04-18 23:49:57 +00:00
Jilles Tjoelker
edebe56497 sh: Abort a wait builtin on any trapped signal.
This is required by POSIX.

PR:		197210
Reported by:	ache
MFC after:	2 weeks
2015-01-31 13:53:29 +00:00
Jilles Tjoelker
85052e7b56 sh: Move some code from onint() to onsig(), making onint() noreturn.
As a result, the INTON macro which is used many times generates fewer
bytes of code.
2014-12-21 23:09:59 +00:00
Jilles Tjoelker
33c5acf038 sh: Eliminate some gotos. 2014-10-05 21:51:36 +00:00
Jilles Tjoelker
d78fdfde89 sh: Remove SIGWINCH handler and just check for resize before every read.
The SIGWINCH handler triggers breakage in libedit which is hard to fix; see
PR bin/169773.

Also, window size changes while a program is in foreground (and it rather
than sh will receive SIGWINCH) will now be picked up automatically.

Downside: it is now certain that a resize is only processed after pressing
<Enter>. If libedit is fixed, sh will most likely have to be changed also.

PR:		bin/180146
2014-01-14 22:56:25 +00:00
Jilles Tjoelker
efd1946c35 sh: Allow trapping SIGINT/SIGQUIT after ignore because of '&'.
If job control is not enabled, background jobs started with  ... &  ignore
SIGINT and SIGQUIT so that they are not affected by such signals that are
intended for the foreground job. However, this should not prevent
reassigning a different action for these signals (as if the shell invocation
inherited these signal actions from its parent).

Austin group issue #751

Example:
  { trap - INT; exec sleep 10; } & wait
A Ctrl+C should terminate the sleep command.
2013-10-30 21:36:15 +00:00
Jilles Tjoelker
b823fb59f1 sh: Fix race condition with signals and wait or set -T.
The change in r238888 was incomplete. It was still possible for a trapped
signal to arrive before the shell went to sleep (sigsuspend()) because a
check was missing or because the signal arrived before in_waitcmd was set.

On SMP, this bug sometimes caused the builtins/wait4.0 test to take 1 second
to execute; it then might or might not fail. On UP, the test almost always
failed.
2013-09-02 21:57:46 +00:00
Jilles Tjoelker
0bdd387178 sh: Remove #define MKINIT.
MKINIT only served for the removed mkinit. Many variables can be static now.
2013-07-25 19:48:15 +00:00
Jilles Tjoelker
46c6b52dfb sh: Fix various compiler warnings.
It now passes WARNS=7 with clang on i386.

GCC 4.2.1 does not understand setjmp() properly so will always trigger
-Wuninitialized. I will not add the volatile keywords to suppress this.
2013-04-01 17:18:22 +00:00
Jilles Tjoelker
3fe1119f98 sh: When executing a trap, keep exit status along with evalskip.
This ensures 'return' in a trap returns the correct status to the caller.

If evalskip is not set or if it is overridden by a previous evalskip, keep
the old behaviour of restoring the exit status from before the trap.
2013-03-03 17:33:59 +00:00
Jilles Tjoelker
25e0f0f577 sh: If a SIGINT or SIGQUIT interrupts "wait", return status 128+sig. 2013-02-23 22:50:57 +00:00
Jilles Tjoelker
1794251add sh: Fix EINTR race condition in "wait" and "set -T" using sigsuspend().
When waiting for child processes using "wait" or if "set -T" is in effect, a
signal interrupts the wait. Make sure there is no window where the signal
handler may be invoked (setting a flag) just before going to sleep.

There is a similar race condition in the shell language, but scripts can
avoid it by exiting from the trap handler or enforcing synchronization using
a fifo.

If SIGCHLD is not trapped, a signal handler must be installed for it. Only
install this handler for the duration of the wait to avoid triggering
unexpected [EINTR] errors elsewhere.

Note that for some reason only SIGINT and SIGQUIT interrupt a "wait"
command. This remains the case.
2012-07-29 18:04:38 +00:00
Jilles Tjoelker
fa7ccda2c4 sh: Reset pendingsigs before checking pending traps, not after.
Otherwise, a signal arriving at exactly the right moment might not be
processed until another signal arrived.
2012-07-15 11:18:52 +00:00
Jean-Sébastien Pédron
01a43bcf7b sh: Fix execution of multiple statements in a trap when evalskip is set
Before this fix, only the first statement of the trap was executed if
evalskip was set. This is for example the case when:
    o  "-e" is set for this shell
    o  a trap is set on EXIT
    o  a function returns 1 and causes the script to abort

Reviewed by:	jilles
MFC after:	2 weeks
2012-01-16 11:07:46 +00:00
Jilles Tjoelker
52c450395a sh: Fix out of bounds array access when trap is used with an invalid signal.
MFC after:	1 week
2012-01-14 21:54:12 +00:00
Jilles Tjoelker
454a02b372 sh: Fix duplicate prototypes for builtins.
Have mkbuiltins write the prototypes for the *cmd functions to builtins.h
instead of builtins.c and include builtins.h in more .c files instead of
duplicating prototypes for *cmd functions in other headers.
2011-06-13 21:03:27 +00:00
Jilles Tjoelker
3835f47c7e sh: Remove special code for shell scripts without magic number.
These are called "shell procedures" in the source.

If execve() failed with [ENOEXEC], the shell would reinitialize itself
and execute the program as a script. This requires a fair amount of code
which is not frequently used (most scripts have a #! magic number).
Therefore just execute a new instance of sh (_PATH_BSHELL) to run the
script.
2011-02-04 22:47:55 +00:00
Jilles Tjoelker
12dacf622b Make sys_signame upper case.
This matches the constants from <signal.h> with 'SIG' removed, which POSIX
requires kill and trap to accept and 'kill -l' to write.

'kill -l', 'trap', 'trap -l' output is now upper case.

In Turkish locales, signal names with an upper case 'I' are now accepted,
while signal names with a lower case 'i' are no longer accepted, and the
output of 'killall -l' now contains proper capital 'I' without dot instead
of a dotted capital 'I'.
2011-02-04 16:40:50 +00:00
Jilles Tjoelker
ebdfd6dc4d sh: If exit is used without args from a trap action, exit on the signal.
This is useful so that it is easier to exit on a signal than to reset the
trap to default and resend the signal. It matches ksh93. POSIX says that
'exit' without args from a trap action uses the exit status from the last
command before the trap, which is different from 'exit $?' and matches this
if the previous command is assumed to have exited on the signal.

If the signal is SIGSTOP, SIGTSTP, SIGTTIN or SIGTTOU, or if the default
action for the signal is to ignore it, a normal _exit(2) is done with exit
status 128+signal_number.
2011-01-16 13:56:41 +00:00
Jilles Tjoelker
a043cc4c68 sh: Fix some things about -- in trap:
* Make 'trap --' do the same as 'trap' instead of nothing.
* Make '--' stop option processing (note that '-' action is not an option).

Side effect: The error message for an unknown option is different.
2011-01-15 21:09:00 +00:00
Jilles Tjoelker
45b3c17647 sh: Make 'trap -l' look like 'kill -l'. 2011-01-14 21:30:27 +00:00
Jilles Tjoelker
70df11eaad sh: Make exit without parameters from EXIT trap POSIX-compliant.
It should use the original exit status, just like falling off the
end of the trap handler.

Outside an EXIT trap, 'exit' is still equivalent to 'exit $?'.
2011-01-08 23:08:13 +00:00
Jilles Tjoelker
5fe9123ff5 sh: Add a function to print warnings (with command name and newline).
This is like error() but without raising an exception.
It is particularly useful as a replacement for the warnx macro in
bltin/bltin.h.
2010-12-21 20:47:06 +00:00
David E. O'Brien
8832864298 In the spirit of r90111, depend on c89 and remove the "STATIC" macro
and its usage.
2010-10-13 22:18:03 +00:00
David E. O'Brien
aa7b6f8259 Consistently use "STATIC" for all functions in order to be able to set
breakpoints with in a debugger.  And use naked "static" for variables.

Noticed by:	bde
2010-10-13 04:01:01 +00:00
Jilles Tjoelker
e3c2cd7237 trap: do not consider a bad signal name a fatal error.
POSIX explicitly prescribes this.
Continue processing any other signals and return status 1.
2009-11-21 20:44:34 +00:00
Jilles Tjoelker
3f228d7484 sh: Use sigaction instead of signal/siginterrupt combination. 2009-11-11 23:13:24 +00:00
Jilles Tjoelker
6e28dacfda Don't skip forking for an external command if any traps are active.
Example:
  sh -c '(trap "echo trapped" EXIT; sleep 3)'
now correctly prints "trapped".

With this check, it is no longer necessary to check for -T
explicitly in that case.

This is a useful bugfix by itself and also important because I plan to
skip forking more often.

PR:		bin/113860 (part of)
PR:		bin/74404 (part of)
Reviewed by:	stefanf
Approved by:	ed (mentor)
2009-06-13 21:10:41 +00:00
Stefan Farfeleder
cb806389db Fix the eval command in combination with set -e. Before this change the shell
would always terminate if eval returned with a non-zero exit status regardless
if the status was actually tested.  Unfortunately a new file-scope variable
is needed, the alternative would only be to add a new parameter to all
built-ins.

PR:	134881
2009-05-31 12:36:14 +00:00
Jens Schweikhardt
00d02f943b Whitespace nits. 2006-04-17 17:55:11 +00:00
Stefan Farfeleder
2a5e306d46 Correctly quote the output when showing the installed trap actions.
PR:		74043
Submitted by:	Jilles Tjoelker
2005-12-08 20:08:36 +00:00
Ralf S. Engelschall
f7d95a075c Various small code cleanups resulting from a code reviewing
and linting procedure:

1. Remove useless sub-expression:

   - if (*start || (!ifsspc && start > string && (nulonly || 1))) {
   + if (*start || (!ifsspc && start > string)) {

   The sub-expression "(nulonly || 1)" always evaluates to true and
   according to CVS logs seems to be just a left-over from some
   debugging and introduced by accident. Removing the sub-expression
   doesn't change semantics and a code inspection showed that the
   variable "nulonly" is also not necessary here in any way (and the
   expression would require fixing instead of removing).

2. Remove dead code:

   -                if (backslash && c == '\\') {
   -                        if (read(STDIN_FILENO, &c, 1) != 1) {
   -                                status = 1;
   -                                break;
   -                        }
   -                        STPUTC(c, p);
   -                } else if (ap[1] != NULL && strchr(ifs, c) != NULL) {
   +                if (ap[1] != NULL && strchr(ifs, c) != NULL) {

   Inspection of the control and data flow showed that variable
   "backslash" is always false (0) when the "if"-expression is
   evaluated, hence the whole block is effectively dead code.
   Additionally, the skipping of characters after a backslash is already
   performed correctly a few lines above, so this code is also not
   needed at all. According to the CVS logs and the ASH 0.2 sources,
   this code existed in this way already since its early days.

3. Cleanup Style:

   - ! trap[signo][0] == '\0' &&
   + ! (trap[signo][0] == '\0') &&

   The expression wants to ensure the trap is not assigned the empty
   string. But the "!" operator has higher precedence than "==", so the
   comparison should be put into parenthesis to form the intended way of
   expression. Nevertheless the code was effectively not really broken
   as both particular NUL comparisons are semantically equal, of course.
   But the parenthesized version is a lot more intuitive.

4. Remove shadowing variable declaration:

   - char *q;

   The declaration of symbol "q" hides another identical declaration of
   "q" in the same context. As the other "q" is already reused multiple
   times and also can be reused again without negative side-effects,
   just remove the shadowing declaration.

5. Just small cosmetics:

   - if (ifsset() != 0)
   + if (ifsset())

   The ifsset() macro is already coded by returning the boolean result
   of a comparison operator, so no need to compare this boolean result
   again against a numerical value. This also aligns the macros usage to
   the remaining existing code.

Reviewed by: stefanf@
2005-09-06 19:30:00 +00:00
Mark Murray
6195fb4102 Remove clause 3 from the UCB licenses.
OK'ed by:	imp, core
2004-04-06 20:06:54 +00:00
Nate Lawson
aa0b7126ba style(9): wrap at 80 columns. 2004-02-12 05:05:56 +00:00
Nate Lawson
97054a769f Handle proper formatting and a buffer overrun when running an old sh on
a system that has sys_nsig > NSIG (i.e. when libc is upgraded.)

Submitted by:	Matt Dillon
Reviewed by:	bde
2004-02-12 05:03:37 +00:00
Nate Lawson
1b13752a03 Use sys_nsig instead of NSIG for the length of the signal arrays. This
is important if we add new signals later.  From DragonflyBSD:
jobs.c:1.4, trap.c:1.3.

Obtained from:	DragonflyBSD
2004-01-28 19:01:10 +00:00
Tim J. Robbins
be58cc483e Avoid calling el_resize() from a signal handler, even though libedit
itself does that if you set EL_SIGNAL. Instead, set a flag and check it
before calling el_gets(). This is safer, but slower to respond to changes.

Pointed out by:	mp
2002-07-24 02:06:07 +00:00
Tim J. Robbins
9de7305e58 Catch SIGWINCH in interactive shells and call el_resize() to update
libedit's idea of the window size.
2002-07-23 15:05:00 +00:00
Tim J. Robbins
2628ebdbd1 Remove broken and incomplete support for old releases of System V,
don't support system that implement getcwd(3) with a pipe to /bin/pwd.
2002-07-19 08:09:04 +00:00
David E. O'Brien
2749b14129 Consistently use FBSDID 2002-06-30 05:15:05 +00:00
Warner Losh
5134c3f799 o __P has been reoved
o Old-style K&R declarations have been converted to new C89 style
o register has been removed
o prototype for main() has been removed (gcc3 makes it an error)
o int main(int argc, char *argv[]) is the preferred main definition.
o Attempt to not break style(9) conformance for declarations more than
  they already are.
o Change
	int
	foo() {
	...
  to
	int
	foo(void)
	{
	...
2002-02-02 06:50:57 +00:00
Peter Wemm
2a4562393f $Id$ -> $FreeBSD$ 1999-08-27 23:15:48 +00:00
Kris Kennaway
46be34b902 Various spelling/formatting changes.
Submitted by: Philippe Charnier <charnier@xp11.frmug.org>
1999-05-08 10:22:15 +00:00
Martin Cracauer
c1c72a3c2a The immediate execution of traps I introduced in September 1998 (to
make /etc/rc interruptible in cases when programs hang with blocked
signals) isn't standard enough.

It is now switched off by default and a new switch -T enables it.

You should update /etc/rc to the version I'm about to commit in a few
minutes to keep it interruptible.
1999-04-01 13:27:36 +00:00
Martin Cracauer
9bbfa41541 Narrow down conditions to break wait() to process traps.
Improve comments.
1998-09-10 22:09:11 +00:00
Martin Cracauer
e6ac45dde2 Fix an inefficiency I introduced in my last commit.
Include "expand.h" vom memalloc.c to pull function declartion into scope
1998-09-10 14:51:06 +00:00
Martin Cracauer
135421ddbf If traps are set, they are now executed even when a signal-blocking
foreground child is running. Formerly, traps were exceuted after the
next child exit.

The enables the user to put a breaking wrapper around a blocking
application:
  (trap 'echo trap ; exit 1' 2; ./pestyblocker; echo -n)

The "echo -n" after the child call is needed to prevent sh from
optimizing the trap-executing shell away. I'm working on this.
1998-09-08 13:16:52 +00:00
Martin Cracauer
1f40b47b46 Improve bookkeeping of in_waitcmd and style fixes.
Submitted by:	Bruce Evans
1998-08-25 09:33:34 +00:00
Martin Cracauer
40d009a717 Re-enable killing childs with SIGQUIT. Spotted by Bruce Evans. 1998-08-25 08:49:47 +00:00
Martin Cracauer
7a8e920bb9 Do not exit on SIGINT in non-interactive shells, fixes PR 1206,
i.e. this makes emacs usable from system(3). Programs called from
shellscripts are now required to exit with proper signal status. That
means, they have to kill themself. Exiting with faked numerical exit
code is not sufficient.

Exit with proper signal status if script exits on signal.

Make the wait builtin interruptable, both with and without traps set.

Use volatile sig_atomic_t where (and only where) appropriate.

(Almost) fix printing of newlines on SIGINT.

Make traps setable from trap handlers. This is needed for shellscripts
that catch SIGINT for cleanup work but intend to exit on it, hance
have to kill themself from a trap handler. I.e. mkdep.

While I'm at it, make it -Wall clean. -Wall is not enabled in
Makefile, since vararg warnx() macro calls in usr.bin/printf/printf.c
are not -Wall-able.
PR:		1206
Obtained from:	Basic SIGINT fix from Bruce Evans
1998-08-24 10:20:37 +00:00