1 /*	$OpenBSD: system.c,v 1.8 2005/08/08 08:05:37 espie Exp $ */
2 /*
3  * Copyright (c) 1988 The Regents of the University of California.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/types.h>
32 #include <sys/wait.h>
33 #include <signal.h>
34 #include <stdlib.h>
35 #include <unistd.h>
36 #include <paths.h>
37 
38 extern char **environ;
39 
40 int
system(const char * command)41 system(const char *command)
42 {
43 	pid_t pid;
44 	sig_t intsave, quitsave;
45 	sigset_t mask, omask;
46 	int pstat;
47 	char *argp[] = {"sh", "-c", NULL, NULL};
48 
49 	if (!command)		/* just checking... */
50 		return(1);
51 
52 	argp[2] = (char *)command;
53 
54 	sigemptyset(&mask);
55 	sigaddset(&mask, SIGCHLD);
56 	sigprocmask(SIG_BLOCK, &mask, &omask);
57 	switch (pid = vfork()) {
58 	case -1:			/* error */
59 		sigprocmask(SIG_SETMASK, &omask, NULL);
60 		return(-1);
61 	case 0:				/* child */
62 		sigprocmask(SIG_SETMASK, &omask, NULL);
63 		execve(_PATH_BSHELL, argp, environ);
64 		_exit(127);
65 	}
66 
67 	intsave = signal(SIGINT, SIG_IGN);
68 	quitsave = signal(SIGQUIT, SIG_IGN);
69 	pid = waitpid(pid, (int *)&pstat, 0);
70 	sigprocmask(SIG_SETMASK, &omask, NULL);
71 	(void)signal(SIGINT, intsave);
72 	(void)signal(SIGQUIT, quitsave);
73 	return (pid == -1 ? -1 : pstat);
74 }
75