src/chroot.c

   1 /* chroot -- run command or shell with special root directory
   2    Copyright (C) 1995, 96 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Written by Roland McGrath.  */
  19
  20 #include <config.h>
  21 #include <stdio.h>
  22 #include <sys/types.h>
  23
  24 #include "system.h"
  25 #include "long-options.h"
  26 #include "error.h"
  27
  28 /* The name this program was run with, for error messages. */
  29 char *program_name;
  30
  31 static void
  32 usage (int status)
  33 {
  34   if (status != 0)
  35     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  36              program_name);
  37   else
  38     {
  39       printf (_("\
  40 Usage: %s [OPTION] NEWROOT [COMMAND...]\n\
  41    or:  %s OPTION\n\
  42 "), program_name, program_name);
  43       printf (_("\
  44 Run COMMAND with root directory set to NEWROOT.\n\
  45 \n\
  46       --help       display this help and exit\n\
  47       --version    output version information and exit\n\
  48 \n\
  49 If no command is given, run ``${SHELL} -i'' (default: /bin/sh).\n\
  50 "));
  51       puts (_("\nReport bugs to sh-utils-bugs@gnu.ai.mit.edu"));
  52     }
  53   exit (status);
  54 }
  55
  56 int
  57 main (int argc, char **argv)
  58 {
  59   program_name = argv[0];
  60
  61   parse_long_options (argc, argv, "chroot", GNU_PACKAGE, VERSION, usage);
  62
  63   if (argc == 1)
  64     {
  65       error (0, 0, _("too few arguments"));
  66       usage (1);
  67     }
  68
  69   if (chroot (argv[1]))
  70     error (1, errno, _("cannot change root directory to %s"), argv[1]);
  71
  72   if (argc == 2)
  73     {
  74       /* No command.  Run an interactive shell.  */
  75       char *shell = getenv ("SHELL");
  76       if (shell == NULL)
  77         shell = "/bin/sh";
  78       argv[0] = shell;
  79       argv[1] = "-i";
  80     }
  81   else
  82     /* The following arguments give the command.  */
  83     argv += 2;
  84
  85   /* Execute the given command.  */
  86   execvp (argv[0], argv);
  87   error (1, errno, _("cannot execute %s"), argv[0]);
  88
  89   exit (1);
  90   return 1;
  91 }