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/* signal.c: a Hugh-approved signal handler. */
#include "rc.h"
#include <signal.h>
#include <setjmp.h>
#include "sigmsgs.h"
#include "jbwrap.h"
#if HAVE_SIGACTION
static void (*sys_signal(int signum, void (*handler)(int)))(int) {
struct sigaction new, old;
new.sa_handler = handler;
new.sa_flags = 0; /* clear SA_RESTART */
sigfillset(&new.sa_mask);
sigaction(signum, &new, &old);
return old.sa_handler;
}
#else
#define sys_signal(sig, func) (signal((sig), (func)))
#endif
void (*sighandlers[NUMOFSIGNALS])(int);
static volatile sig_atomic_t sigcount, caught[NUMOFSIGNALS];
extern void catcher(int s) {
if (caught[s] == 0) {
sigcount++;
caught[s] = 1;
}
sys_signal(s, catcher);
#if READLINE
if (rl_active)
siglongjmp(rl_buf.j, s);
#endif /* READLINE */
#if HAVE_RESTARTABLE_SYSCALLS
if (slow) {
siglongjmp(slowbuf.j, s);
}
#endif
}
extern void sigchk() {
void (*h)(int);
int s, i;
if (sigcount == 0)
return; /* ho hum; life as usual */
if (forked)
exit(1); /* exit unconditionally on a signal in a child process */
for (i = 0, s = -1; i < NUMOFSIGNALS; i++)
if (caught[i] != 0) {
s = i;
--sigcount;
caught[s] = 0;
break;
}
if (s == -1)
panic("all-zero sig vector with nonzero sigcount");
if ((h = sighandlers[s]) == SIG_DFL)
panic("caught signal set to SIG_DFL");
if (h == SIG_IGN)
panic("caught signal set to SIG_IGN");
(*h)(s);
}
extern void (*rc_signal(int s, void (*h)(int)))(int) {
void (*old)(int);
sigchk();
old = sighandlers[s];
if (h == SIG_DFL || h == SIG_IGN) {
sighandlers[s] = h;
sys_signal(s, h);
} else {
sighandlers[s] = h;
sys_signal(s, catcher);
}
return old;
}
extern void initsignal() {
void (*h)(int);
int i;
#if HAVE_SYSV_SIGCLD
/* Ensure that SIGCLD is not SIG_IGN. Solaris's rshd does this. :-( */
h = sys_signal(SIGCLD, SIG_IGN);
if (h != SIG_IGN && h != SIG_ERR)
sys_signal(SIGCLD, h);
else
sys_signal(SIGCLD, SIG_DFL);
#endif
for (i = 1; i < NUMOFSIGNALS; i++) {
#ifdef SIGKILL
if (i == SIGKILL) continue;
#endif
#ifdef SIGSTOP
if (i == SIGSTOP) continue;
#endif
h = sys_signal(i, SIG_IGN);
if (h != SIG_IGN && h != SIG_ERR)
sys_signal(i, h);
sighandlers[i] = h;
}
}
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