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
|
#include <stddef.h>
#include <signal.h>
#include <unistd.h>
int
system(command)
char * command;
{
int wait_val, wait_ret, 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);
printf("Waiting for child %d\n", pid);
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;
}
|
