src/chroot.c

   1 /* chroot -- run command or shell with special root directory
   2    Copyright (C) 95, 96, 1997, 1999-2004 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  17
  18 /* Written by Roland McGrath.  */
  19
  20 #include <config.h>
  21 #include <getopt.h>
  22 #include <stdio.h>
  23 #include <sys/types.h>
  24
  25 #include "system.h"
  26 #include "error.h"
  27 #include "long-options.h"
  28 #include "quote.h"
  29
  30 /* The official name of this program (e.g., no `g' prefix).  */
  31 #define PROGRAM_NAME "chroot"
  32
  33 #define AUTHORS "Roland McGrath"
  34
  35 /* The name this program was run with, for error messages. */
  36 char *program_name;
  37
  38 void
  39 usage (int status)
  40 {
  41   if (status != EXIT_SUCCESS)
  42     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  43              program_name);
  44   else
  45     {
  46       printf (_("\
  47 Usage: %s NEWROOT [COMMAND...]\n\
  48   or:  %s OPTION\n\
  49 "), program_name, program_name);
  50       fputs (_("\
  51 Run COMMAND with root directory set to NEWROOT.\n\
  52 \n\
  53 "), stdout);
  54       fputs (HELP_OPTION_DESCRIPTION, stdout);
  55       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  56       fputs (_("\
  57 \n\
  58 If no command is given, run ``${SHELL} -i'' (default: /bin/sh).\n\
  59 "), stdout);
  60       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
  61     }
  62   exit (status);
  63 }
  64
  65 int
  66 main (int argc, char **argv)
  67 {
  68   initialize_main (&argc, &argv);
  69   program_name = argv[0];
  70   setlocale (LC_ALL, "");
  71   bindtextdomain (PACKAGE, LOCALEDIR);
  72   textdomain (PACKAGE);
  73
  74   initialize_exit_failure (EXIT_FAIL);
  75   atexit (close_stdout);
  76
  77   parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
  78                       usage, AUTHORS, (char const *) NULL);
  79   if (getopt_long (argc, argv, "+", NULL, NULL) != -1)
  80     usage (EXIT_FAIL);
  81
  82   if (argc <= optind)
  83     {
  84       error (0, 0, _("missing operand"));
  85       usage (EXIT_FAIL);
  86     }
  87
  88   if (chroot (argv[optind]) != 0)
  89     error (EXIT_FAIL, errno, _("cannot change root directory to %s"), argv[1]);
  90
  91   if (chdir ("/"))
  92     error (EXIT_FAIL, errno, _("cannot chdir to root directory"));
  93
  94   if (argc == optind + 1)
  95     {
  96       /* No command.  Run an interactive shell.  */
  97       char *shell = getenv ("SHELL");
  98       if (shell == NULL)
  99         shell = "/bin/sh";
 100       argv[0] = shell;
 101       argv[1] = "-i";
 102       argv[2] = NULL;
 103     }
 104   else
 105     {
 106       /* The following arguments give the command.  */
 107       argv += optind + 1;
 108     }
 109
 110   /* Execute the given command.  */
 111   execvp (argv[0], argv);
 112
 113   {
 114     int exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
 115     error (0, errno, _("cannot run command %s"), quote (argv[0]));
 116     exit (exit_status);
 117   }
 118 }