1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
#define wait4 __wait4
#define execl __execl
#define signal __signal
#include <stdio.h>
#include <stddef.h>
#include <signal.h>
#include <unistd.h>
#include <sys/wait.h>
/* uClinux-2.0 has vfork, but Linux 2.0 doesn't */
#include <sys/syscall.h>
#if ! defined __NR_vfork
#define vfork fork
#endif
int __libc_system(char *command)
{
int wait_val, pid;
__sighandler_t save_quit, save_int, save_chld;
if (command == 0)
return 1;
save_quit = signal(SIGQUIT, SIG_IGN);
save_int = signal(SIGINT, SIG_IGN);
save_chld = signal(SIGCHLD, SIG_DFL);
if ((pid = vfork()) < 0) {
signal(SIGQUIT, save_quit);
signal(SIGINT, save_int);
signal(SIGCHLD, save_chld);
return -1;
}
if (pid == 0) {
signal(SIGQUIT, SIG_DFL);
signal(SIGINT, SIG_DFL);
signal(SIGCHLD, SIG_DFL);
execl("/bin/sh", "sh", "-c", command, (char *) 0);
_exit(127);
}
/* Signals are not absolutly guarenteed with vfork */
signal(SIGQUIT, SIG_IGN);
signal(SIGINT, SIG_IGN);
#if 0
__printf("Waiting for child %d\n", pid);
#endif
if (wait4(pid, &wait_val, 0, 0) == -1)
wait_val = -1;
signal(SIGQUIT, save_quit);
signal(SIGINT, save_int);
signal(SIGCHLD, save_chld);
return wait_val;
}
weak_alias(__libc_system, system)
|
