coreutils/chroot.c

/* vi: set sw=4 ts=4: */
/*
 * Mini chroot implementation for busybox
 *
 *
 * Copyright (C) 1999 by Lineo, inc.
 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include "internal.h"
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>


static const char chroot_usage[] = "chroot NEWROOT [COMMAND...]\n\n"

	"Run COMMAND with root directory set to NEWROOT.\n";



int chroot_main(int argc, char **argv)
{
	if ((argc < 2) || (**(argv + 1) == '-')) {
		usage(chroot_usage);
	}
	argc--;
	argv++;

	if (chroot(*argv) || (chdir("/"))) {
		fprintf(stderr, "chroot: cannot change root directory to %s: %s\n",
				*argv, strerror(errno));
		exit(FALSE);
	}

	argc--;
	argv++;
	if (argc >= 1) {
		fprintf(stderr, "command: %s\n", *argv);
		execvp(*argv, argv);
	} else {
		char *prog;

		prog = getenv("SHELL");
		if (!prog)
			prog = "/bin/sh";
		execlp(prog, prog, NULL);
	}
	fprintf(stderr, "chroot: cannot execute %s: %s\n",
			*argv, strerror(errno));
	exit(FALSE);
}