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system.c revision 1.16.12.1 
      1 /*	$NetBSD: system.c,v 1.16.12.1 2001/11/14 19:32:03 nathanw Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #if defined(LIBC_SCCS) && !defined(lint)
     38 #if 0
     39 static char sccsid[] = "@(#)system.c	8.1 (Berkeley) 6/4/93";
     40 #else
     41 __RCSID("$NetBSD: system.c,v 1.16.12.1 2001/11/14 19:32:03 nathanw Exp $");
     42 #endif
     43 #endif /* LIBC_SCCS and not lint */
     44 
     45 #include "namespace.h"
     46 #include <sys/types.h>
     47 #include <sys/wait.h>
     48 #include <errno.h>
     49 #include <signal.h>
     50 #include <stdlib.h>
     51 #include <unistd.h>
     52 #include <paths.h>
     53 
     54 extern char **environ;
     55 
     56 int
     57 system(command)
     58 	const char *command;
     59 {
     60 	pid_t pid;
     61 	struct sigaction intsa, quitsa, sa;
     62 	sigset_t nmask, omask;
     63 	int pstat;
     64 	char *argp[] = {"sh", "-c", /* LINTED */(char *)command, NULL};
     65 
     66 	if (command == NULL)		/* just checking... */
     67 		return(1);
     68 
     69 	sa.sa_handler = SIG_IGN;
     70 	sigemptyset(&sa.sa_mask);
     71 	sa.sa_flags = 0;
     72 
     73 	if (sigaction(SIGINT, &sa, &intsa) == -1)
     74 		return -1;
     75 	if (sigaction(SIGQUIT, &sa, &quitsa) == -1)
     76 		return -1;
     77 
     78 	sigemptyset(&nmask);
     79 	sigaddset(&nmask, SIGCHLD);
     80 	if (sigprocmask(SIG_BLOCK, &nmask, &omask) == -1)
     81 		return -1;
     82 
     83 	switch(pid = vfork()) {
     84 	case -1:			/* error */
     85 		sigaction(SIGINT, &intsa, NULL);
     86 		sigaction(SIGQUIT, &quitsa, NULL);
     87 		(void)sigprocmask(SIG_SETMASK, &omask, NULL);
     88 		return -1;
     89 	case 0:				/* child */
     90 		sigaction(SIGINT, &intsa, NULL);
     91 		sigaction(SIGQUIT, &quitsa, NULL);
     92 		(void)sigprocmask(SIG_SETMASK, &omask, NULL);
     93 		execve(_PATH_BSHELL, argp, environ);
     94 		_exit(127);
     95 	}
     96 
     97 	while (waitpid(pid, &pstat, 0) == -1) {
     98 		if (errno != EINTR) {
     99 			pstat = -1;
    100 			break;
    101 		}
    102 	}
    103 
    104 	sigaction(SIGINT, &intsa, NULL);
    105 	sigaction(SIGQUIT, &quitsa, NULL);
    106 	(void)sigprocmask(SIG_SETMASK, &omask, NULL);
    107 
    108 	return (pstat);
    109 }
    110