If job control is not enabled, a background job (... &) ignores SIGINT and
SIGQUIT, but this can be reverted using the trap builtin in the same shell
environment.
Using the set builtin to change options would also revert SIGINT and SIGQUIT
to their previous dispositions.
This broke due to r317298. Calling setsignal() reverts the effect of
ignoresig().
Reported by: bdrewery
MFC after: 1 week
Mainly focus on files that use BSD 3-Clause license.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
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
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.
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.
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.
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 $?'.
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)
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
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)
{
...
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
cast value that was always ignored. Rev.1.9 of trap.c made this
more bogus by returning a semantically different value after calling
siginterrupt(). Avoid these problems by not returning a value.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
merge of parallel duplicate work by Steve Price and myself. :-]
There are some changes to the build that are my fault... mkinit.c was
trying (poorly) to duplicate some of the work that make(1) is designed to
do. The Makefile hackery is my fault too, the depend list was incomplete
because of some explicit OBJS+= entries, so mkdep wasn't picking up their
source file #includes.
This closes a pile of /bin/sh PR's, but not all of them..
Submitted by: Steve Price <steve@bonsai.hiwaay.net>, peter
