src/chroot.c

   1 /* chroot -- run command or shell with special root directory
   2    Copyright (C) 95, 96, 1997, 1999-2004, 2007 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 3 of the License, or
   7    (at your option) 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, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Roland McGrath.  */
  18
  19 #include <config.h>
  20 #include <getopt.h>
  21 #include <stdio.h>
  22 #include <sys/types.h>
  23
  24 #include "system.h"
  25 #include "error.h"
  26 #include "long-options.h"
  27 #include "quote.h"
  28
  29 /* The official name of this program (e.g., no `g' prefix).  */
  30 #define PROGRAM_NAME "chroot"
  31
  32 #define AUTHORS "Roland McGrath"
  33
  34 /* The name this program was run with, for error messages. */
  35 char *program_name;
  36
  37 void
  38 usage (int status)
  39 {
  40   if (status != EXIT_SUCCESS)
  41     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  42              program_name);
  43   else
  44     {
  45       printf (_("\
  46 Usage: %s NEWROOT [COMMAND...]\n\
  47   or:  %s OPTION\n\
  48 "), program_name, program_name);
  49       fputs (_("\
  50 Run COMMAND with root directory set to NEWROOT.\n\
  51 \n\
  52 "), stdout);
  53       fputs (HELP_OPTION_DESCRIPTION, stdout);
  54       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  55       fputs (_("\
  56 \n\
  57 If no command is given, run ``${SHELL} -i'' (default: /bin/sh).\n\
  58 "), stdout);
  59       emit_bug_reporting_address ();
  60     }
  61   exit (status);
  62 }
  63
  64 int
  65 main (int argc, char **argv)
  66 {
  67   initialize_main (&argc, &argv);
  68   program_name = argv[0];
  69   setlocale (LC_ALL, "");
  70   bindtextdomain (PACKAGE, LOCALEDIR);
  71   textdomain (PACKAGE);
  72
  73   initialize_exit_failure (EXIT_FAILURE);
  74   atexit (close_stdout);
  75
  76   parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, VERSION,
  77                       usage, AUTHORS, (char const *) NULL);
  78   if (getopt_long (argc, argv, "+", NULL, NULL) != -1)
  79     usage (EXIT_FAILURE);
  80
  81   if (argc <= optind)
  82     {
  83       error (0, 0, _("missing operand"));
  84       usage (EXIT_FAILURE);
  85     }
  86
  87   if (chroot (argv[optind]) != 0)
  88     error (EXIT_FAILURE, errno, _("cannot change root directory to %s"), argv[1]);
  89
  90   if (chdir ("/"))
  91     error (EXIT_FAILURE, errno, _("cannot chdir to root directory"));
  92
  93   if (argc == optind + 1)
  94     {
  95       /* No command.  Run an interactive shell.  */
  96       char *shell = getenv ("SHELL");
  97       if (shell == NULL)
  98         shell = "/bin/sh";
  99       argv[0] = shell;
 100       argv[1] = "-i";
 101       argv[2] = NULL;
 102     }
 103   else
 104     {
 105       /* The following arguments give the command.  */
 106       argv += optind + 1;
 107     }
 108
 109   /* Execute the given command.  */
 110   execvp (argv[0], argv);
 111
 112   {
 113     int exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
 114     error (0, errno, _("cannot run command %s"), quote (argv[0]));
 115     exit (exit_status);
 116   }
 117 }