src/chown.c

   1 /* chown -- change user and group ownership of files
   2    Copyright (C) 89, 90, 91, 1995-2007 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 /*
  18               |                       user
  19               | unchanged                 explicit
  20  -------------|-------------------------+-------------------------|
  21  g unchanged  | ---                     | chown u                 |
  22  r            |-------------------------+-------------------------|
  23  o explicit   | chgrp g or chown .g     | chown u.g               |
  24  u            |-------------------------+-------------------------|
  25  p from passwd| ---                     | chown u.                |
  26               |-------------------------+-------------------------|
  27
  28    Written by David MacKenzie <djm@gnu.ai.mit.edu>. */
  29
  30 #include <config.h>
  31 #include <stdio.h>
  32 #include <sys/types.h>
  33 #include <getopt.h>
  34
  35 #include "system.h"
  36 #include "chown-core.h"
  37 #include "error.h"
  38 #include "fts_.h"
  39 #include "quote.h"
  40 #include "root-dev-ino.h"
  41 #include "userspec.h"
  42
  43 /* The official name of this program (e.g., no `g' prefix).  */
  44 #define PROGRAM_NAME "chown"
  45
  46 #define AUTHORS "David MacKenzie", "Jim Meyering"
  47
  48 /* The name the program was run with. */
  49 char *program_name;
  50
  51 /* The argument to the --reference option.  Use the owner and group IDs
  52    of this file.  This file must exist.  */
  53 static char *reference_file;
  54
  55 /* For long options that have no equivalent short option, use a
  56    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  57 enum
  58 {
  59   DEREFERENCE_OPTION = CHAR_MAX + 1,
  60   FROM_OPTION,
  61   NO_PRESERVE_ROOT,
  62   PRESERVE_ROOT,
  63   REFERENCE_FILE_OPTION
  64 };
  65
  66 static struct option const long_options[] =
  67 {
  68   {"recursive", no_argument, NULL, 'R'},
  69   {"changes", no_argument, NULL, 'c'},
  70   {"dereference", no_argument, NULL, DEREFERENCE_OPTION},
  71   {"from", required_argument, NULL, FROM_OPTION},
  72   {"no-dereference", no_argument, NULL, 'h'},
  73   {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
  74   {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
  75   {"quiet", no_argument, NULL, 'f'},
  76   {"silent", no_argument, NULL, 'f'},
  77   {"reference", required_argument, NULL, REFERENCE_FILE_OPTION},
  78   {"verbose", no_argument, NULL, 'v'},
  79   {GETOPT_HELP_OPTION_DECL},
  80   {GETOPT_VERSION_OPTION_DECL},
  81   {NULL, 0, NULL, 0}
  82 };
  83
  84 void
  85 usage (int status)
  86 {
  87   if (status != EXIT_SUCCESS)
  88     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  89              program_name);
  90   else
  91     {
  92       printf (_("\
  93 Usage: %s [OPTION]... [OWNER][:[GROUP]] FILE...\n\
  94   or:  %s [OPTION]... --reference=RFILE FILE...\n\
  95 "),
  96               program_name, program_name);
  97       fputs (_("\
  98 Change the owner and/or group of each FILE to OWNER and/or GROUP.\n\
  99 With --reference, change the owner and group of each FILE to those of RFILE.\n\
 100 \n\
 101   -c, --changes          like verbose but report only when a change is made\n\
 102       --dereference      affect the referent of each symbolic link (this is\n\
 103                          the default), rather than the symbolic link itself\n\
 104 "), stdout);
 105       fputs (_("\
 106   -h, --no-dereference   affect each symbolic link instead of any referenced\n\
 107                          file (useful only on systems that can change the\n\
 108                          ownership of a symlink)\n\
 109 "), stdout);
 110       fputs (_("\
 111       --from=CURRENT_OWNER:CURRENT_GROUP\n\
 112                          change the owner and/or group of each file only if\n\
 113                          its current owner and/or group match those specified\n\
 114                          here.  Either may be omitted, in which case a match\n\
 115                          is not required for the omitted attribute.\n\
 116 "), stdout);
 117       fputs (_("\
 118       --no-preserve-root  do not treat `/' specially (the default)\n\
 119       --preserve-root    fail to operate recursively on `/'\n\
 120 "), stdout);
 121       fputs (_("\
 122   -f, --silent, --quiet  suppress most error messages\n\
 123       --reference=RFILE  use RFILE's owner and group rather than\n\
 124                          specifying OWNER:GROUP values\n\
 125   -R, --recursive        operate on files and directories recursively\n\
 126   -v, --verbose          output a diagnostic for every file processed\n\
 127 \n\
 128 "), stdout);
 129       fputs (_("\
 130 The following options modify how a hierarchy is traversed when the -R\n\
 131 option is also specified.  If more than one is specified, only the final\n\
 132 one takes effect.\n\
 133 \n\
 134   -H                     if a command line argument is a symbolic link\n\
 135                          to a directory, traverse it\n\
 136   -L                     traverse every symbolic link to a directory\n\
 137                          encountered\n\
 138   -P                     do not traverse any symbolic links (default)\n\
 139 \n\
 140 "), stdout);
 141       fputs (HELP_OPTION_DESCRIPTION, stdout);
 142       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 143       fputs (_("\
 144 \n\
 145 Owner is unchanged if missing.  Group is unchanged if missing, but changed\n\
 146 to login group if implied by a `:' following a symbolic OWNER.\n\
 147 OWNER and GROUP may be numeric as well as symbolic.\n\
 148 "), stdout);
 149       printf (_("\
 150 \n\
 151 Examples:\n\
 152   %s root /u        Change the owner of /u to \"root\".\n\
 153   %s root:staff /u  Likewise, but also change its group to \"staff\".\n\
 154   %s -hR root /u    Change the owner of /u and subfiles to \"root\".\n\
 155 "),
 156               program_name, program_name, program_name);
 157       emit_bug_reporting_address ();
 158     }
 159   exit (status);
 160 }
 161
 162 int
 163 main (int argc, char **argv)
 164 {
 165   bool preserve_root = false;
 166
 167   uid_t uid = -1;       /* Specified uid; -1 if not to be changed. */
 168   gid_t gid = -1;       /* Specified gid; -1 if not to be changed. */
 169
 170   /* Change the owner (group) of a file only if it has this uid (gid).
 171      -1 means there's no restriction.  */
 172   uid_t required_uid = -1;
 173   gid_t required_gid = -1;
 174
 175   /* Bit flags that control how fts works.  */
 176   int bit_flags = FTS_PHYSICAL;
 177
 178   /* 1 if --dereference, 0 if --no-dereference, -1 if neither has been
 179      specified.  */
 180   int dereference = -1;
 181
 182   struct Chown_option chopt;
 183   bool ok;
 184   int optc;
 185
 186   initialize_main (&argc, &argv);
 187   program_name = argv[0];
 188   setlocale (LC_ALL, "");
 189   bindtextdomain (PACKAGE, LOCALEDIR);
 190   textdomain (PACKAGE);
 191
 192   atexit (close_stdout);
 193
 194   chopt_init (&chopt);
 195
 196   while ((optc = getopt_long (argc, argv, "HLPRcfhv", long_options, NULL))
 197          != -1)
 198     {
 199       switch (optc)
 200         {
 201         case 'H': /* Traverse command-line symlinks-to-directories.  */
 202           bit_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
 203           break;
 204
 205         case 'L': /* Traverse all symlinks-to-directories.  */
 206           bit_flags = FTS_LOGICAL;
 207           break;
 208
 209         case 'P': /* Traverse no symlinks-to-directories.  */
 210           bit_flags = FTS_PHYSICAL;
 211           break;
 212
 213         case 'h': /* --no-dereference: affect symlinks */
 214           dereference = 0;
 215           break;
 216
 217         case DEREFERENCE_OPTION: /* --dereference: affect the referent
 218                                     of each symlink */
 219           dereference = 1;
 220           break;
 221
 222         case NO_PRESERVE_ROOT:
 223           preserve_root = false;
 224           break;
 225
 226         case PRESERVE_ROOT:
 227           preserve_root = true;
 228           break;
 229
 230         case REFERENCE_FILE_OPTION:
 231           reference_file = optarg;
 232           break;
 233
 234         case FROM_OPTION:
 235           {
 236             char *u_dummy, *g_dummy;
 237             const char *e = parse_user_spec (optarg,
 238                                              &required_uid, &required_gid,
 239                                              &u_dummy, &g_dummy);
 240             if (e)
 241               error (EXIT_FAILURE, 0, "%s: %s", e, quote (optarg));
 242             break;
 243           }
 244
 245         case 'R':
 246           chopt.recurse = true;
 247           break;
 248
 249         case 'c':
 250           chopt.verbosity = V_changes_only;
 251           break;
 252
 253         case 'f':
 254           chopt.force_silent = true;
 255           break;
 256
 257         case 'v':
 258           chopt.verbosity = V_high;
 259           break;
 260
 261         case_GETOPT_HELP_CHAR;
 262         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 263         default:
 264           usage (EXIT_FAILURE);
 265         }
 266     }
 267
 268   if (chopt.recurse)
 269     {
 270       if (bit_flags == FTS_PHYSICAL)
 271         {
 272           if (dereference == 1)
 273             error (EXIT_FAILURE, 0,
 274                    _("-R --dereference requires either -H or -L"));
 275           dereference = 0;
 276         }
 277     }
 278   else
 279     {
 280       bit_flags = FTS_PHYSICAL;
 281     }
 282   chopt.affect_symlink_referent = (dereference != 0);
 283
 284   if (argc - optind < (reference_file ? 1 : 2))
 285     {
 286       if (argc <= optind)
 287         error (0, 0, _("missing operand"));
 288       else
 289         error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
 290       usage (EXIT_FAILURE);
 291     }
 292
 293   if (reference_file)
 294     {
 295       struct stat ref_stats;
 296       if (stat (reference_file, &ref_stats))
 297         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 298                quote (reference_file));
 299
 300       uid = ref_stats.st_uid;
 301       gid = ref_stats.st_gid;
 302       chopt.user_name = uid_to_name (ref_stats.st_uid);
 303       chopt.group_name = gid_to_name (ref_stats.st_gid);
 304     }
 305   else
 306     {
 307       const char *e = parse_user_spec (argv[optind], &uid, &gid,
 308                                        &chopt.user_name, &chopt.group_name);
 309       if (e)
 310         error (EXIT_FAILURE, 0, "%s: %s", e, quote (argv[optind]));
 311
 312       /* If a group is specified but no user, set the user name to the
 313          empty string so that diagnostics say "ownership :GROUP"
 314          rather than "group GROUP".  */
 315       if (!chopt.user_name && chopt.group_name)
 316         chopt.user_name = "";
 317
 318       optind++;
 319     }
 320
 321   if (chopt.recurse & preserve_root)
 322     {
 323       static struct dev_ino dev_ino_buf;
 324       chopt.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 325       if (chopt.root_dev_ino == NULL)
 326         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 327                quote ("/"));
 328     }
 329
 330   ok = chown_files (argv + optind, bit_flags,
 331                     uid, gid,
 332                     required_uid, required_gid, &chopt);
 333
 334   chopt_free (&chopt);
 335
 336   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 337 }