OpenSolaris_b135/cmd/mail/pipletr.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
/*	  All Rights Reserved  	*/

#pragma ident	"%Z%%M%	%I%	%E% SMI" 

#include "mail.h"

int
dowait(pid_t pidval)
{
	pid_t w;
	int status;
	void (*istat)(), (*qstat)();

	/*
		Parent temporarily ignores signals so it will remain 
		around for command to finish
	*/
	istat = signal(SIGINT, SIG_IGN);
	qstat = signal(SIGQUIT, SIG_IGN);

	while ((w = wait(&status)) != pidval && w != CERROR);
	if (w == CERROR) {
		status = -errno;
		signal(SIGINT, istat);
		signal(SIGQUIT, qstat);
		return (status);
	}

	signal(SIGINT, istat);
	signal(SIGQUIT, qstat);
	status = ((status>>8)&0xFF);  		/* extract 8 high order bits */
	return (status);
}

/*
	invoke shell to execute command waiting for command to terminate
		s	-> command string
	return:
		status	-> command exit status
*/
int
systm(char *s)
{
	pid_t	pid;

	/*
		Spawn the shell to execute command, however, since the 
		mail command runs setgid mode reset the effective group 
		id to the real group id so that the command does not
		acquire any special privileges
	*/
	if ((pid = fork()) == CHILD) {
		setuid(my_uid);
		setgid(my_gid);
#ifdef SVR3
		execl("/bin/sh", "sh", "-c", s, (char*)NULL);
#else
		execl("/usr/bin/sh", "sh", "-c", s, (char*)NULL);
#endif
		exit(127);
	}
	return (dowait(pid));
}