[unix-history] / usr / src / usr.sbin / chroot / chroot.c

/*
* Copyright (c) 1988 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1988 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)chroot.c    5.4 (Berkeley) %G%";
#endif /* not lint */

#include <stdio.h>
#include "pathnames.h"

main(argc, argv)
       int argc;
       char **argv;
{
       extern int errno;
       char *shell, *getenv(), *strerror();

       if (argc < 2) {
               fprintf(stderr, "usage: chroot newroot [command]\n");
               exit(1);
       }
       if (chdir(argv[1]) || chroot(argv[1]))
               fatal(argv[1]);
       setuid(getuid());
       if (argv[2]) {
               execvp(argv[2], &argv[2]);
               fatal(argv[2]);
       } else {
               if (!(shell = getenv("SHELL")))
                       shell = _PATH_BSHELL;
               execlp(shell, shell, "-i", (char *)NULL);
               fatal(shell);
       }
       /* NOTREACHED */
}

fatal(msg)
       char *msg;
{
       extern int errno;

       fprintf(stderr, "chroot: %s: %s\n", msg, strerror(errno));
       exit(1);
}