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system.c revision 1.7.4.1 
      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, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #if defined(LIBC_SCCS) && !defined(lint)
     35 /*static char *sccsid = "from: @(#)system.c	5.10 (Berkeley) 2/23/91";*/
     36 static char *rcsid = "$Id: system.c,v 1.7.4.1 1995/05/02 19:36:47 jtc Exp $";
     37 #endif /* LIBC_SCCS and not lint */
     38 
     39 #include "namespace.h"
     40 #include <sys/types.h>
     41 #include <sys/wait.h>
     42 #include <signal.h>
     43 #include <stdlib.h>
     44 #include <stddef.h>
     45 #include <unistd.h>
     46 #include <paths.h>
     47 
     48 extern char **environ;
     49 
     50 system(command)
     51 	const char *command;
     52 {
     53 	pid_t pid;
     54 	sig_t intsave, quitsave;
     55 	int omask;
     56 	int pstat;
     57 	char *argp[] = {"sh", "-c", (char *) command, NULL};
     58 
     59 	if (!command)		/* just checking... */
     60 		return(1);
     61 
     62 	omask = sigblock(sigmask(SIGCHLD));
     63 	switch(pid = vfork()) {
     64 	case -1:			/* error */
     65 		(void)sigsetmask(omask);
     66 		return(-1);
     67 	case 0:				/* child */
     68 		(void)sigsetmask(omask);
     69 		execve(_PATH_BSHELL, argp, environ);
     70 		_exit(127);
     71 	}
     72 
     73 	intsave = signal(SIGINT, SIG_IGN);
     74 	quitsave = signal(SIGQUIT, SIG_IGN);
     75 	pid = waitpid(pid, (int *)&pstat, 0);
     76 	(void)sigsetmask(omask);
     77 	(void)signal(SIGINT, intsave);
     78 	(void)signal(SIGQUIT, quitsave);
     79 	return(pid == -1 ? -1 : pstat);
     80 }
     81