/*	$OpenBSD: system.c,v 1.13 2022/05/21 00:53:53 millert Exp $ */
/*
 * Copyright (c) 1988 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <paths.h>

int
system(const char *command)
{
	pid_t pid, cpid;
	struct sigaction intsave, quitsave, sa;
	sigset_t mask, omask;
	int pstat;
	char *argp[] = {"sh", "-c", NULL, NULL};

	if (!command)		/* just checking... */
		return(1);

	argp[2] = (char *)command;

	sigemptyset(&mask);
	sigaddset(&mask, SIGCHLD);
	sigaddset(&mask, SIGINT);
	sigaddset(&mask, SIGQUIT);
	sigprocmask(SIG_BLOCK, &mask, &omask);
	switch (cpid = vfork()) {
	case -1:			/* error */
		sigprocmask(SIG_SETMASK, &omask, NULL);
		return(-1);
	case 0:				/* child */
		sigprocmask(SIG_SETMASK, &omask, NULL);
		execve(_PATH_BSHELL, argp, environ);
		_exit(127);
	}

	/* Ignore SIGINT and SIGQUIT while waiting for command to complete. */
	memset(&sa, 0, sizeof(sa));
	sigemptyset(&sa.sa_mask);
	sa.sa_handler = SIG_IGN;
	sigaction(SIGINT, &sa, &intsave);
	sigaction(SIGQUIT, &sa, &quitsave);
	sigemptyset(&mask);
	sigaddset(&mask, SIGINT);
	sigaddset(&mask, SIGQUIT);
	sigprocmask(SIG_UNBLOCK, &mask, NULL);

	do {
		pid = waitpid(cpid, &pstat, 0);
	} while (pid == -1 && errno == EINTR);

	sigprocmask(SIG_SETMASK, &omask, NULL);
	sigaction(SIGINT, &intsave, NULL);
	sigaction(SIGQUIT, &quitsave, NULL);
	return (pid == -1 ? -1 : pstat);
}
DEF_STRONG(system);