1 /*	$OpenBSD: system.c,v 1.11 2015/10/23 04:44:41 guenther 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 <errno.h>
34 #include <signal.h>
35 #include <stdlib.h>
36 #include <unistd.h>
37 #include <paths.h>
38 
39 extern char **environ;
40 
41 int
system(const char * command)42 system(const char *command)
43 {
44 	pid_t pid, cpid;
45 	struct sigaction intsave, quitsave;
46 	sigset_t mask, omask;
47 	int pstat;
48 	char *argp[] = {"sh", "-c", NULL, NULL};
49 
50 	if (!command)		/* just checking... */
51 		return(1);
52 
53 	argp[2] = (char *)command;
54 
55 	sigemptyset(&mask);
56 	sigaddset(&mask, SIGCHLD);
57 	sigprocmask(SIG_BLOCK, &mask, &omask);
58 	switch (cpid = vfork()) {
59 	case -1:			/* error */
60 		sigprocmask(SIG_SETMASK, &omask, NULL);
61 		return(-1);
62 	case 0:				/* child */
63 		sigprocmask(SIG_SETMASK, &omask, NULL);
64 		execve(_PATH_BSHELL, argp, environ);
65 		_exit(127);
66 	}
67 
68 	sigaction(SIGINT, NULL, &intsave);
69 	sigaction(SIGQUIT, NULL, &quitsave);
70 	do {
71 		pid = waitpid(cpid, &pstat, 0);
72 	} while (pid == -1 && errno == EINTR);
73 	sigprocmask(SIG_SETMASK, &omask, NULL);
74 	sigaction(SIGINT, &intsave, NULL);
75 	sigaction(SIGQUIT, &quitsave, NULL);
76 	return (pid == -1 ? -1 : pstat);
77 }
78 DEF_STRONG(system);
79