summaryrefslogtreecommitdiff
path: root/src/chroot.c
blob: 9a2c913ee3704d95a4f1436fda2f27ad7e154dcc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
/* chroot -- run command or shell with special root directory
   Copyright (C) 95, 96, 1997, 1999-2004 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* Written by Roland McGrath.  */

#include <config.h>
#include <stdio.h>
#include <sys/types.h>

#include "system.h"
#include "error.h"
#include "long-options.h"
#include "quote.h"

/* The official name of this program (e.g., no `g' prefix).  */
#define PROGRAM_NAME "chroot"

#define AUTHORS "Roland McGrath"

/* Exit statuses.  */
enum
  {
    /* found the specified command but failed to invoke it.  */
    CHROOT_FOUND_BUT_CANNOT_INVOKE = 126,

    /* `chroot' itself failed, or did not find the specified command.  */
    CHROOT_FAILURE = 127
  };

/* The name this program was run with, for error messages. */
char *program_name;

void
usage (int status)
{
  if (status != 0)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
	     program_name);
  else
    {
      printf (_("\
Usage: %s NEWROOT [COMMAND...]\n\
  or:  %s OPTION\n\
"), program_name, program_name);
      fputs (_("\
Run COMMAND with root directory set to NEWROOT.\n\
\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      fputs (_("\
\n\
If no command is given, run ``${SHELL} -i'' (default: /bin/sh).\n\
"), stdout);
      printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    }
  exit (status);
}

int
main (int argc, char **argv)
{
  initialize_main (&argc, &argv);
  program_name = argv[0];
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  atexit (close_stdout);

  parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
		      usage, AUTHORS, (char const *) NULL);
  if (argc <= 1)
    {
      error (0, 0, _("too few arguments"));
      usage (CHROOT_FAILURE);
    }

  if (chroot (argv[1]))
    error (CHROOT_FAILURE, errno,
	   _("cannot change root directory to %s"), argv[1]);

  if (chdir ("/"))
    error (CHROOT_FAILURE, errno, _("cannot chdir to root directory"));

  if (argc == 2)
    {
      /* No command.  Run an interactive shell.  */
      char *shell = getenv ("SHELL");
      if (shell == NULL)
	shell = "/bin/sh";
      argv[0] = shell;
      argv[1] = "-i";
    }
  else
    {
      /* The following arguments give the command.  */
      argv += 2;
    }

  /* Execute the given command.  */
  execvp (argv[0], argv);

  {
    int exit_status = (errno == ENOENT
		       ? CHROOT_FAILURE
		       : CHROOT_FOUND_BUT_CANNOT_INVOKE);
    error (0, errno, _("cannot run command %s"), quote (argv[0]));
    exit (exit_status);
  }
}