1 #include <signal.h>
2 #include "subcmd-util.h"
3 #include "sigchain.h"
4
5 #define SIGCHAIN_MAX_SIGNALS 32
6
7 struct sigchain_signal {
8 sigchain_fun *old;
9 int n;
10 int alloc;
11 };
12 static struct sigchain_signal signals[SIGCHAIN_MAX_SIGNALS];
13
14 static void check_signum(int sig)
15 {
16 if (sig < 1 || sig >= SIGCHAIN_MAX_SIGNALS)
17 die("BUG: signal out of range: %d", sig);
18 }
19
20 static int sigchain_push(int sig, sigchain_fun f)
21 {
22 struct sigchain_signal *s = signals + sig;
23 check_signum(sig);
24
25 ALLOC_GROW(s->old, s->n + 1, s->alloc);
26 s->old[s->n] = signal(sig, f);
27 if (s->old[s->n] == SIG_ERR)
28 return -1;
29 s->n++;
30 return 0;
31 }
32
33 int sigchain_pop(int sig)
34 {
35 struct sigchain_signal *s = signals + sig;
36 check_signum(sig);
37 if (s->n < 1)
38 return 0;
39
40 if (signal(sig, s->old[s->n - 1]) == SIG_ERR)
41 return -1;
42 s->n--;
43 return 0;
44 }
45
46 void sigchain_push_common(sigchain_fun f)
47 {
48 sigchain_push(SIGINT, f);
49 sigchain_push(SIGHUP, f);
50 sigchain_push(SIGTERM, f);
51 sigchain_push(SIGQUIT, f);
52 sigchain_push(SIGPIPE, f);
53 }
54
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