src/chown.c

   1 /* chown -- change user and group ownership of files
   2    Copyright (C) 89, 90, 91, 1995-2009 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 \
  47   proper_name ("David MacKenzie"), \
  48   proper_name ("Jim Meyering")
  49
  50 /* The argument to the --reference option.  Use the owner and group IDs
  51    of this file.  This file must exist.  */
  52 static char *reference_file;
  53
  54 /* For long options that have no equivalent short option, use a
  55    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  56 enum
  57 {
  58   DEREFERENCE_OPTION = CHAR_MAX + 1,
  59   FROM_OPTION,
  60   NO_PRESERVE_ROOT,
  61   PRESERVE_ROOT,
  62   REFERENCE_FILE_OPTION
  63 };
  64
  65 static struct option const long_options[] =
  66 {
  67   {"recursive", no_argument, NULL, 'R'},
  68   {"changes", no_argument, NULL, 'c'},
  69   {"dereference", no_argument, NULL, DEREFERENCE_OPTION},
  70   {"from", required_argument, NULL, FROM_OPTION},
  71   {"no-dereference", no_argument, NULL, 'h'},
  72   {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
  73   {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
  74   {"quiet", no_argument, NULL, 'f'},
  75   {"silent", no_argument, NULL, 'f'},
  76   {"reference", required_argument, NULL, REFERENCE_FILE_OPTION},
  77   {"verbose", no_argument, NULL, 'v'},
  78   {GETOPT_HELP_OPTION_DECL},
  79   {GETOPT_VERSION_OPTION_DECL},
  80   {NULL, 0, NULL, 0}
  81 };
  82
  83 void
  84 usage (int status)
  85 {
  86   if (status != EXIT_SUCCESS)
  87     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  88              program_name);
  89   else
  90     {
  91       printf (_("\
  92 Usage: %s [OPTION]... [OWNER][:[GROUP]] FILE...\n\
  93   or:  %s [OPTION]... --reference=RFILE FILE...\n\
  94 "),
  95               program_name, program_name);
  96       fputs (_("\
  97 Change the owner and/or group of each FILE to OWNER and/or GROUP.\n\
  98 With --reference, change the owner and group of each FILE to those of RFILE.\n\
  99 \n\
 100   -c, --changes          like verbose but report only when a change is made\n\
 101       --dereference      affect the referent of each symbolic link (this is\n\
 102                          the default), rather than the symbolic link itself\n\
 103 "), stdout);
 104       fputs (_("\
 105   -h, --no-dereference   affect each symbolic link instead of any referenced\n\
 106                          file (useful only on systems that can change the\n\
 107                          ownership of a symlink)\n\
 108 "), stdout);
 109       fputs (_("\
 110       --from=CURRENT_OWNER:CURRENT_GROUP\n\
 111                          change the owner and/or group of each file only if\n\
 112                          its current owner and/or group match those specified\n\
 113                          here.  Either may be omitted, in which case a match\n\
 114                          is not required for the omitted attribute.\n\
 115 "), stdout);
 116       fputs (_("\
 117       --no-preserve-root  do not treat `/' specially (the default)\n\
 118       --preserve-root    fail to operate recursively on `/'\n\
 119 "), stdout);
 120       fputs (_("\
 121   -f, --silent, --quiet  suppress most error messages\n\
 122       --reference=RFILE  use RFILE's owner and group rather than\n\
 123                          specifying OWNER:GROUP values\n\
 124   -R, --recursive        operate on files and directories recursively\n\
 125   -v, --verbose          output a diagnostic for every file processed\n\
 126 \n\
 127 "), stdout);
 128       fputs (_("\
 129 The following options modify how a hierarchy is traversed when the -R\n\
 130 option is also specified.  If more than one is specified, only the final\n\
 131 one takes effect.\n\
 132 \n\
 133   -H                     if a command line argument is a symbolic link\n\
 134                          to a directory, traverse it\n\
 135   -L                     traverse every symbolic link to a directory\n\
 136                          encountered\n\
 137   -P                     do not traverse any symbolic links (default)\n\
 138 \n\
 139 "), stdout);
 140       fputs (HELP_OPTION_DESCRIPTION, stdout);
 141       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 142       fputs (_("\
 143 \n\
 144 Owner is unchanged if missing.  Group is unchanged if missing, but changed\n\
 145 to login group if implied by a `:' following a symbolic OWNER.\n\
 146 OWNER and GROUP may be numeric as well as symbolic.\n\
 147 "), stdout);
 148       printf (_("\
 149 \n\
 150 Examples:\n\
 151   %s root /u        Change the owner of /u to \"root\".\n\
 152   %s root:staff /u  Likewise, but also change its group to \"staff\".\n\
 153   %s -hR root /u    Change the owner of /u and subfiles to \"root\".\n\
 154 "),
 155               program_name, program_name, program_name);
 156       emit_bug_reporting_address ();
 157     }
 158   exit (status);
 159 }
 160
 161 int
 162 main (int argc, char **argv)
 163 {
 164   bool preserve_root = false;
 165
 166   uid_t uid = -1;       /* Specified uid; -1 if not to be changed. */
 167   gid_t gid = -1;       /* Specified gid; -1 if not to be changed. */
 168
 169   /* Change the owner (group) of a file only if it has this uid (gid).
 170      -1 means there's no restriction.  */
 171   uid_t required_uid = -1;
 172   gid_t required_gid = -1;
 173
 174   /* Bit flags that control how fts works.  */
 175   int bit_flags = FTS_PHYSICAL;
 176
 177   /* 1 if --dereference, 0 if --no-dereference, -1 if neither has been
 178      specified.  */
 179   int dereference = -1;
 180
 181   struct Chown_option chopt;
 182   bool ok;
 183   int optc;
 184
 185   initialize_main (&argc, &argv);
 186   set_program_name (argv[0]);
 187   setlocale (LC_ALL, "");
 188   bindtextdomain (PACKAGE, LOCALEDIR);
 189   textdomain (PACKAGE);
 190
 191   atexit (close_stdout);
 192
 193   chopt_init (&chopt);
 194
 195   while ((optc = getopt_long (argc, argv, "HLPRcfhv", long_options, NULL))
 196          != -1)
 197     {
 198       switch (optc)
 199         {
 200         case 'H': /* Traverse command-line symlinks-to-directories.  */
 201           bit_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
 202           break;
 203
 204         case 'L': /* Traverse all symlinks-to-directories.  */
 205           bit_flags = FTS_LOGICAL;
 206           break;
 207
 208         case 'P': /* Traverse no symlinks-to-directories.  */
 209           bit_flags = FTS_PHYSICAL;
 210           break;
 211
 212         case 'h': /* --no-dereference: affect symlinks */
 213           dereference = 0;
 214           break;
 215
 216         case DEREFERENCE_OPTION: /* --dereference: affect the referent
 217                                     of each symlink */
 218           dereference = 1;
 219           break;
 220
 221         case NO_PRESERVE_ROOT:
 222           preserve_root = false;
 223           break;
 224
 225         case PRESERVE_ROOT:
 226           preserve_root = true;
 227           break;
 228
 229         case REFERENCE_FILE_OPTION:
 230           reference_file = optarg;
 231           break;
 232
 233         case FROM_OPTION:
 234           {
 235             char *u_dummy, *g_dummy;
 236             const char *e = parse_user_spec (optarg,
 237                                              &required_uid, &required_gid,
 238                                              &u_dummy, &g_dummy);
 239             if (e)
 240               error (EXIT_FAILURE, 0, "%s: %s", e, quote (optarg));
 241             break;
 242           }
 243
 244         case 'R':
 245           chopt.recurse = true;
 246           break;
 247
 248         case 'c':
 249           chopt.verbosity = V_changes_only;
 250           break;
 251
 252         case 'f':
 253           chopt.force_silent = true;
 254           break;
 255
 256         case 'v':
 257           chopt.verbosity = V_high;
 258           break;
 259
 260         case_GETOPT_HELP_CHAR;
 261         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 262         default:
 263           usage (EXIT_FAILURE);
 264         }
 265     }
 266
 267   if (chopt.recurse)
 268     {
 269       if (bit_flags == FTS_PHYSICAL)
 270         {
 271           if (dereference == 1)
 272             error (EXIT_FAILURE, 0,
 273                    _("-R --dereference requires either -H or -L"));
 274           dereference = 0;
 275         }
 276     }
 277   else
 278     {
 279       bit_flags = FTS_PHYSICAL;
 280     }
 281   chopt.affect_symlink_referent = (dereference != 0);
 282
 283   if (argc - optind < (reference_file ? 1 : 2))
 284     {
 285       if (argc <= optind)
 286         error (0, 0, _("missing operand"));
 287       else
 288         error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
 289       usage (EXIT_FAILURE);
 290     }
 291
 292   if (reference_file)
 293     {
 294       struct stat ref_stats;
 295       if (stat (reference_file, &ref_stats))
 296         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 297                quote (reference_file));
 298
 299       uid = ref_stats.st_uid;
 300       gid = ref_stats.st_gid;
 301       chopt.user_name = uid_to_name (ref_stats.st_uid);
 302       chopt.group_name = gid_to_name (ref_stats.st_gid);
 303     }
 304   else
 305     {
 306       const char *e = parse_user_spec (argv[optind], &uid, &gid,
 307                                        &chopt.user_name, &chopt.group_name);
 308       if (e)
 309         error (EXIT_FAILURE, 0, "%s: %s", e, quote (argv[optind]));
 310
 311       /* If a group is specified but no user, set the user name to the
 312          empty string so that diagnostics say "ownership :GROUP"
 313          rather than "group GROUP".  */
 314       if (!chopt.user_name && chopt.group_name)
 315         chopt.user_name = bad_cast ("");
 316
 317       optind++;
 318     }
 319
 320   if (chopt.recurse & preserve_root)
 321     {
 322       static struct dev_ino dev_ino_buf;
 323       chopt.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 324       if (chopt.root_dev_ino == NULL)
 325         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 326                quote ("/"));
 327     }
 328
 329   bit_flags |= FTS_DEFER_STAT;
 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 }