src/chroot.c

   1 /* chroot -- run command or shell with special root directory
   2    Copyright (C) 95, 96, 1997, 1999-2002 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 #include "closeout.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 != 0)
  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       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
  60     }
  61   exit (status);
  62 }
  63
  64 int
  65 main (int argc, char **argv)
  66 {
  67   program_name = argv[0];
  68   setlocale (LC_ALL, "");
  69   bindtextdomain (PACKAGE, LOCALEDIR);
  70   textdomain (PACKAGE);
  71
  72   atexit (close_stdout);
  73
  74   parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
  75                       AUTHORS, usage);
  76   if (argc == 1)
  77     {
  78       error (0, 0, _("too few arguments"));
  79       usage (EXIT_FAILURE);
  80     }
  81
  82   if (chroot (argv[1]))
  83     error (EXIT_FAILURE, errno,
  84            _("cannot change root directory to %s"), argv[1]);
  85
  86   if (chdir ("/"))
  87     error (EXIT_FAILURE, errno, _("cannot chdir to root directory"));
  88
  89   if (argc == 2)
  90     {
  91       /* No command.  Run an interactive shell.  */
  92       char *shell = getenv ("SHELL");
  93       if (shell == NULL)
  94         shell = "/bin/sh";
  95       argv[0] = shell;
  96       argv[1] = "-i";
  97     }
  98   else
  99     {
 100       /* The following arguments give the command.  */
 101       argv += 2;
 102     }
 103
 104   /* Execute the given command.  */
 105   execvp (argv[0], argv);
 106
 107   {
 108     int exit_status = (errno == ENOENT ? 127 : 126);
 109     error (0, errno, "%s", argv[0]);
 110     exit (exit_status);
 111   }
 112 }