/* Looks like they want to do a kill. Do that */
while (arg) {
- /* Support shell 'space' trick */
- if (arg[0] == ' ')
- arg++;
+#if ENABLE_ASH || ENABLE_HUSH
+ /*
+ * We need to support shell's "hack formats" of
+ * " -PRGP_ID" (yes, with a leading space)
+ * and " PID1 PID2 PID3" (with degenerate case "")
+ */
+ while (*arg != '\0') {
+ char *end;
+ if (*arg == ' ')
+ arg++;
+ pid = bb_strtoi(arg, &end, 10);
+ if (errno && (errno != EINVAL || *end != ' ')) {
+ bb_error_msg("invalid number '%s'", arg);
+ errors++;
+ } else if (kill(pid, signo) != 0) {
+ bb_perror_msg("can't kill pid %d", (int)pid);
+ errors++;
+ }
+ arg = end; /* can only point to ' ' or '\0' now */
+ }
+#else
pid = bb_strtoi(arg, NULL, 10);
if (errno) {
bb_error_msg("invalid number '%s'", arg);
bb_perror_msg("can't kill pid %d", (int)pid);
errors++;
}
+#endif
arg = *++argv;
}
return errors;
static int FAST_FUNC
killcmd(int argc, char **argv)
{
- int i = 1;
if (argv[1] && strcmp(argv[1], "-l") != 0) {
+ int i = 1;
do {
if (argv[i][0] == '%') {
- struct job *jp = getjob(argv[i], 0);
- unsigned pid = jp->ps[0].ps_pid;
- /* Enough space for ' -NNN<nul>' */
- argv[i] = alloca(sizeof(int)*3 + 3);
- /* kill_main has matching code to expect
- * leading space. Needed to not confuse
- * negative pids with "kill -SIGNAL_NO" syntax */
- sprintf(argv[i], " -%u", pid);
+ /*
+ * "kill %N" - job kill
+ * Converting to pgrp / pid kill
+ */
+ struct job *jp;
+ char *dst;
+ int j, n;
+
+ jp = getjob(argv[i], 0);
+ /*
+ * In jobs started under job control, we signal
+ * entire process group by kill -PGRP_ID.
+ * This happens, f.e., in interactive shell.
+ *
+ * Otherwise, we signal each child via
+ * kill PID1 PID2 PID3.
+ * Testcases:
+ * sh -c 'sleep 1|sleep 1 & kill %1'
+ * sh -c 'true|sleep 2 & sleep 1; kill %1'
+ * sh -c 'true|sleep 1 & sleep 2; kill %1'
+ */
+ n = jp->nprocs; /* can't be 0 (I hope) */
+ if (jp->jobctl)
+ n = 1;
+ dst = alloca(n * sizeof(int)*4);
+ argv[i] = dst;
+ for (j = 0; j < n; j++) {
+ struct procstat *ps = &jp->ps[j];
+ /* Skip non-running and not-stopped members
+ * (i.e. dead members) of the job
+ */
+ if (ps->ps_status != -1 && !WIFSTOPPED(ps->ps_status))
+ continue;
+ /*
+ * kill_main has matching code to expect
+ * leading space. Needed to not confuse
+ * negative pids with "kill -SIGNAL_NO" syntax
+ */
+ dst += sprintf(dst, jp->jobctl ? " -%u" : " %u", (int)ps->ps_pid);
+ }
+ *dst = '\0';
}
} while (argv[++i]);
}
break;
job = job->prev_job;
}
- } else
+ } else {
job = getjob(*argv, 0);
+ }
/* loop until process terminated or stopped */
while (job->state == JOBRUNNING)
blocking_wait_with_raise_on_sig();
#if JOBS
/* do job control only in root shell */
doing_jobctl = 0;
- if (mode != FORK_NOJOB && jp->jobctl && !oldlvl) {
+ if (mode != FORK_NOJOB && jp->jobctl && oldlvl == 0) {
pid_t pgrp;
if (jp->nprocs == 0)
ash_msg_and_raise_error("can't open '%s'", bb_dev_null);
}
}
- if (!oldlvl) {
+ if (oldlvl == 0) {
if (iflag) { /* why if iflag only? */
setsignal(SIGINT);
setsignal(SIGTERM);
--- /dev/null
+Sending SIGINT to main shell PID
--- /dev/null
+# What should happen if non-interactive shell gets SIGINT?
+
+(sleep 1; echo Sending SIGINT to main shell PID; exec kill -INT $$) &
+
+# We create a child which exits with 0 even on SIGINT
+# (This is truly necessary only if SIGINT is generated by ^C,
+# in this testcase even bare "sleep 2" would do because
+# we don't send SIGINT _to_ the_ child_...)
+$THIS_SH -c 'trap "exit 0" SIGINT; sleep 2'
+
+# In one second, we (main shell) get SIGINT here.
+# The question is whether we should, or should not, exit.
+
+# bash will not stop here. It will execute next command(s).
+
+# The rationale for this is described here:
+# http://www.cons.org/cracauer/sigint.html
+#
+# Basically, bash will not exit on SIGINT immediately if it waits
+# for a child. It will wait for the child to exit.
+# If child exits NOT by dying on SIGINT, then bash will not exit.
+#
+# The idea is that the following script:
+# | emacs file.txt
+# | more cmds
+# User may use ^C to interrupt editor's ops like search. But then
+# emacs exits normally. User expects that script doesn't stop.
+#
+# This is a nice idea, but detecting "did process really exit
+# with SIGINT?" is racy. Consider:
+# | bash -c 'while true; do /bin/true; done'
+# When ^C is pressed while bash waits for /bin/true to exit,
+# it may happen that /bin/true exits with exitcode 0 before
+# ^C is delivered to it as SIGINT. bash will see SIGINT, then
+# it will see that child exited with 0, and bash will NOT EXIT.
+
+# Therefore we do not implement bash behavior.
+# I'd say that emacs need to put itself into a separate pgrp
+# to isolate shell from getting stray SIGINTs from ^C.
+
+echo Next command after SIGINT was executed
--- /dev/null
+Sending SIGINT to main shell PID
--- /dev/null
+# What should happen if non-interactive shell gets SIGINT?
+
+(sleep 1; echo Sending SIGINT to main shell PID; exec kill -INT $$) &
+
+# We create a child which exits with 0 even on SIGINT
+# (This is truly necessary only if SIGINT is generated by ^C,
+# in this testcase even bare "sleep 2" would do because
+# we don't send SIGINT _to_ the_ child_...)
+$THIS_SH -c 'trap "exit 0" SIGINT; sleep 2'
+
+# In one second, we (main shell) get SIGINT here.
+# The question is whether we should, or should not, exit.
+
+# bash will not stop here. It will execute next command(s).
+
+# The rationale for this is described here:
+# http://www.cons.org/cracauer/sigint.html
+#
+# Basically, bash will not exit on SIGINT immediately if it waits
+# for a child. It will wait for the child to exit.
+# If child exits NOT by dying on SIGINT, then bash will not exit.
+#
+# The idea is that the following script:
+# | emacs file.txt
+# | more cmds
+# User may use ^C to interrupt editor's ops like search. But then
+# emacs exits normally. User expects that script doesn't stop.
+#
+# This is a nice idea, but detecting "did process really exit
+# with SIGINT?" is racy. Consider:
+# | bash -c 'while true; do /bin/true; done'
+# When ^C is pressed while bash waits for /bin/true to exit,
+# it may happen that /bin/true exits with exitcode 0 before
+# ^C is delivered to it as SIGINT. bash will see SIGINT, then
+# it will see that child exited with 0, and bash will NOT EXIT.
+
+# Therefore we do not implement bash behavior.
+# I'd say that emacs need to put itself into a separate pgrp
+# to isolate shell from getting stray SIGINTs from ^C.
+
+echo Next command after SIGINT was executed
projects / oweals / busybox.git / commitdiff