xref: /csrg-svn/lib/libc/stdlib/system.c (revision 42138)
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	5.8 (Berkeley) 05/16/90";
20 #endif /* LIBC_SCCS and not lint */
21 
22 #include <sys/types.h>
23 #include <sys/signal.h>
24 #include <sys/wait.h>
25 #include <stdlib.h>
26 #include <stddef.h>
27 #include <paths.h>
28 
29 system(command)
30 	char *command;
31 {
32 	union wait pstat;
33 	pid_t pid, waitpid();
34 	int omask;
35 	sig_t intsave, quitsave;
36 
37 	if (!command)		/* just checking... */
38 		return(1);
39 
40 	omask = sigblock(sigmask(SIGCHLD));
41 	switch(pid = vfork()) {
42 	case -1:			/* error */
43 		(void)sigsetmask(omask);
44 		pstat.w_status = 0;
45 		pstat.w_retcode = 127;
46 		return(pstat.w_status);
47 	case 0:				/* child */
48 		(void)sigsetmask(omask);
49 		execl(_PATH_BSHELL, "sh", "-c", command, (char *)NULL);
50 		_exit(127);
51 	}
52 	intsave = signal(SIGINT, SIG_IGN);
53 	quitsave = signal(SIGQUIT, SIG_IGN);
54 	pid = waitpid(pid, &pstat, 0);
55 	(void)sigsetmask(omask);
56 	(void)signal(SIGINT, intsave);
57 	(void)signal(SIGQUIT, quitsave);
58 	return(pid == -1 ? -1 : pstat.w_status);
59 }
60