1#include <unistd.h>
 2#include <stdlib.h>
 3#include <signal.h>
 4#include <sys/wait.h>
 5#include <spawn.h>
 6#include <errno.h>
 7#include "pthread_impl.h"
 8
 9extern char **__environ;
10
11int system(const char *cmd)
12{
13	pid_t pid;
14	sigset_t old, reset;
15	struct sigaction sa = { .sa_handler = SIG_IGN }, oldint, oldquit;
16	int status = -1, ret;
17	posix_spawnattr_t attr;
18
19	pthread_testcancel();
20
21	if (!cmd) return 1;
22
23	sigaction(SIGINT, &sa, &oldint);
24	sigaction(SIGQUIT, &sa, &oldquit);
25	sigaddset(&sa.sa_mask, SIGCHLD);
26	sigprocmask(SIG_BLOCK, &sa.sa_mask, &old);
27
28	sigemptyset(&reset);
29	if (oldint.sa_handler != SIG_IGN) sigaddset(&reset, SIGINT);
30	if (oldquit.sa_handler != SIG_IGN) sigaddset(&reset, SIGQUIT);
31	posix_spawnattr_init(&attr);
32	posix_spawnattr_setsigmask(&attr, &old);
33	posix_spawnattr_setsigdefault(&attr, &reset);
34	posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGDEF|POSIX_SPAWN_SETSIGMASK);
35	ret = posix_spawn(&pid, "/bin/sh", 0, &attr,
36		(char *[]){"sh", "-c", (char *)cmd, 0}, __environ);
37	posix_spawnattr_destroy(&attr);
38
39	if (!ret) while (waitpid(pid, &status, 0)<0 && errno == EINTR);
40	sigaction(SIGINT, &oldint, NULL);
41	sigaction(SIGQUIT, &oldquit, NULL);
42	sigprocmask(SIG_SETMASK, &old, NULL);
43
44	if (ret) errno = ret;
45	return status;
46}