src/chroot.c

   1 /* chroot -- run command or shell with special root directory
   2    Copyright (C) 95, 96, 1997, 1999 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 official name of this program (e.g., no `g' prefix).  */
  29 #define PROGRAM_NAME "chroot"
  30
  31 #define AUTHORS "Roland McGrath"
  32
  33 /* The name this program was run with, for error messages. */
  34 char *program_name;
  35
  36 void
  37 usage (int status)
  38 {
  39   if (status != 0)
  40     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  41              program_name);
  42   else
  43     {
  44       printf (_("\
  45 Usage: %s [OPTION] NEWROOT [COMMAND...]\n\
  46   or:  %s OPTION\n\
  47 "), program_name, program_name);
  48       printf (_("\
  49 Run COMMAND with root directory set to NEWROOT.\n\
  50 \n\
  51       --help       display this help and exit\n\
  52       --version    output version information and exit\n\
  53 \n\
  54 If no command is given, run ``${SHELL} -i'' (default: /bin/sh).\n\
  55 "));
  56       puts (_("\nReport bugs to <bug-sh-utils@gnu.org>."));
  57     }
  58   exit (status);
  59 }
  60
  61 int
  62 main (int argc, char **argv)
  63 {
  64   program_name = argv[0];
  65   setlocale (LC_ALL, "");
  66   bindtextdomain (PACKAGE, LOCALEDIR);
  67   textdomain (PACKAGE);
  68
  69   parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
  70                       AUTHORS, usage);
  71   if (argc == 1)
  72     {
  73       error (0, 0, _("too few arguments"));
  74       usage (1);
  75     }
  76
  77   if (chroot (argv[1]))
  78     error (1, errno, _("cannot change root directory to %s"), argv[1]);
  79
  80   if (chdir ("/"))
  81     error (1, errno, _("cannot chdir to root directory"));
  82
  83   if (argc == 2)
  84     {
  85       /* No command.  Run an interactive shell.  */
  86       char *shell = getenv ("SHELL");
  87       if (shell == NULL)
  88         shell = "/bin/sh";
  89       argv[0] = shell;
  90       argv[1] = "-i";
  91     }
  92   else
  93     {
  94       /* The following arguments give the command.  */
  95       argv += 2;
  96     }
  97
  98   /* Execute the given command.  */
  99   execvp (argv[0], argv);
 100   error (1, errno, _("cannot execute %s"), argv[0]);
 101
 102   exit (1);
 103   return 1;
 104 }