xref: /csrg-svn/lib/libc/stdlib/system.c (revision 36688)
1 /*
2  * Copyright (c) 1988 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  */
17 
18 #if defined(LIBC_SCCS) && !defined(lint)
19 static char sccsid[] = "@(#)system.c	5.5 (Berkeley) 02/06/89";
20 #endif /* LIBC_SCCS and not lint */
21 
22 #include <sys/types.h>
23 #include <sys/wait.h>
24 #include <sys/signal.h>
25 #include <stdio.h>
26 
27 system(command)
28 	char *command;
29 {
30 	union wait pstat;
31 	pid_t pid, waitpid();
32 	int omask, (*i)(), (*q)();
33 
34 	omask = sigblock(sigmask(SIGCHLD));
35 	switch(pid = vfork()) {
36 	case -1:			/* error */
37 		(void)sigsetmask(omask);
38 		pstat.w_status = 0;
39 		pstat.w_retcode = 127;
40 		return(pstat.w_status);
41 	case 0:				/* child */
42 		(void)sigsetmask(omask);
43 		execl("/bin/sh", "sh", "-c", command, (char *)NULL);
44 		_exit(127);
45 	}
46 	i = signal(SIGINT, SIG_IGN);
47 	q = signal(SIGQUIT, SIG_IGN);
48 	pid = waitpid(pid, &pstat, 0);
49 	(void)sigsetmask(omask);
50 	(void)signal(SIGINT, i);
51 	(void)signal(SIGQUIT, q);
52 	return(pid == -1 ? -1 : pstat.w_status);
53 }
54