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#include "libc.h"
9
10extern char **__environ;
11
12int system(const char *cmd)
13{
14	pid_t pid;
15	sigset_t old, reset;
16	struct sigaction sa = { .sa_handler = SIG_IGN }, oldint, oldquit;
17	int status = 0x7f00, ret;
18	posix_spawnattr_t attr;
19
20	pthread_testcancel();
21
22	if (!cmd) return 1;
23
24	sigaction(SIGINT, &sa, &oldint);
25	sigaction(SIGQUIT, &sa, &oldquit);
26	sigaddset(&sa.sa_mask, SIGCHLD);
27	sigprocmask(SIG_BLOCK, &sa.sa_mask, &old);
28
29	sigemptyset(&reset);
30	if (oldint.sa_handler != SIG_IGN) sigaddset(&reset, SIGINT);
31	if (oldquit.sa_handler != SIG_IGN) sigaddset(&reset, SIGQUIT);
32	posix_spawnattr_init(&attr);
33	posix_spawnattr_setsigmask(&attr, &old);
34	posix_spawnattr_setsigdefault(&attr, &reset);
35	posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGDEF|POSIX_SPAWN_SETSIGMASK);
36	ret = posix_spawn(&pid, "/bin/sh", 0, &attr,
37		(char *[]){"sh", "-c", (char *)cmd, 0}, __environ);
38	posix_spawnattr_destroy(&attr);
39
40	if (!ret) while (waitpid(pid, &status, 0)<0 && errno == EINTR);
41	sigaction(SIGINT, &oldint, NULL);
42	sigaction(SIGQUIT, &oldquit, NULL);
43	sigprocmask(SIG_SETMASK, &old, NULL);
44
45	if (ret) errno = ret;
46	return status;
47}
48