src/chown.c

   1 /* chown -- change user and group ownership of files
   2    Copyright (C) 89, 90, 91, 1995-2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  17
  18 /*
  19               |                       user
  20               | unchanged                 explicit
  21  -------------|-------------------------+-------------------------|
  22  g unchanged  | ---                     | chown u                 |
  23  r            |-------------------------+-------------------------|
  24  o explicit   | chgrp g or chown .g     | chown u.g               |
  25  u            |-------------------------+-------------------------|
  26  p from passwd| ---                     | chown u.                |
  27               |-------------------------+-------------------------|
  28
  29    Written by David MacKenzie <djm@gnu.ai.mit.edu>. */
  30
  31 #include <config.h>
  32 #include <stdio.h>
  33 #include <sys/types.h>
  34 #include <getopt.h>
  35
  36 #include "system.h"
  37 #include "chown-core.h"
  38 #include "error.h"
  39 #include "fts_.h"
  40 #include "quote.h"
  41 #include "root-dev-ino.h"
  42 #include "userspec.h"
  43
  44 /* The official name of this program (e.g., no `g' prefix).  */
  45 #define PROGRAM_NAME "chown"
  46
  47 #define AUTHORS "David MacKenzie", "Jim Meyering"
  48
  49 /* The name the program was run with. */
  50 char *program_name;
  51
  52 /* The argument to the --reference option.  Use the owner and group IDs
  53    of this file.  This file must exist.  */
  54 static char *reference_file;
  55
  56 /* For long options that have no equivalent short option, use a
  57    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  58 enum
  59 {
  60   DEREFERENCE_OPTION = CHAR_MAX + 1,
  61   FROM_OPTION,
  62   NO_PRESERVE_ROOT,
  63   PRESERVE_ROOT,
  64   REFERENCE_FILE_OPTION
  65 };
  66
  67 static struct option const long_options[] =
  68 {
  69   {"recursive", no_argument, NULL, 'R'},
  70   {"changes", no_argument, NULL, 'c'},
  71   {"dereference", no_argument, NULL, DEREFERENCE_OPTION},
  72   {"from", required_argument, NULL, FROM_OPTION},
  73   {"no-dereference", no_argument, NULL, 'h'},
  74   {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
  75   {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
  76   {"quiet", no_argument, NULL, 'f'},
  77   {"silent", no_argument, NULL, 'f'},
  78   {"reference", required_argument, NULL, REFERENCE_FILE_OPTION},
  79   {"verbose", no_argument, NULL, 'v'},
  80   {GETOPT_HELP_OPTION_DECL},
  81   {GETOPT_VERSION_OPTION_DECL},
  82   {NULL, 0, NULL, 0}
  83 };
  84
  85 void
  86 usage (int status)
  87 {
  88   if (status != EXIT_SUCCESS)
  89     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  90              program_name);
  91   else
  92     {
  93       printf (_("\
  94 Usage: %s [OPTION]... [OWNER][:[GROUP]] FILE...\n\
  95   or:  %s [OPTION]... --reference=RFILE FILE...\n\
  96 "),
  97               program_name, program_name);
  98       fputs (_("\
  99 Change the owner and/or group of each FILE to OWNER and/or GROUP.\n\
 100 With --reference, change the owner and group of each FILE to those of RFILE.\n\
 101 \n\
 102   -c, --changes          like verbose but report only when a change is made\n\
 103       --dereference      affect the referent of each symbolic link (this is\n\
 104                          the default), rather than the symbolic link itself\n\
 105 "), stdout);
 106       fputs (_("\
 107   -h, --no-dereference   affect each symbolic link instead of any referenced\n\
 108                          file (useful only on systems that can change the\n\
 109                          ownership of a symlink)\n\
 110 "), stdout);
 111       fputs (_("\
 112       --from=CURRENT_OWNER:CURRENT_GROUP\n\
 113                          change the owner and/or group of each file only if\n\
 114                          its current owner and/or group match those specified\n\
 115                          here.  Either may be omitted, in which case a match\n\
 116                          is not required for the omitted attribute.\n\
 117 "), stdout);
 118       fputs (_("\
 119       --no-preserve-root  do not treat `/' specially (the default)\n\
 120       --preserve-root    fail to operate recursively on `/'\n\
 121 "), stdout);
 122       fputs (_("\
 123   -f, --silent, --quiet  suppress most error messages\n\
 124       --reference=RFILE  use RFILE's owner and group rather than\n\
 125                          specifying OWNER:GROUP values\n\
 126   -R, --recursive        operate on files and directories recursively\n\
 127   -v, --verbose          output a diagnostic for every file processed\n\
 128 \n\
 129 "), stdout);
 130       fputs (_("\
 131 The following options modify how a hierarchy is traversed when the -R\n\
 132 option is also specified.  If more than one is specified, only the final\n\
 133 one takes effect.\n\
 134 \n\
 135   -H                     if a command line argument is a symbolic link\n\
 136                          to a directory, traverse it\n\
 137   -L                     traverse every symbolic link to a directory\n\
 138                          encountered\n\
 139   -P                     do not traverse any symbolic links (default)\n\
 140 \n\
 141 "), stdout);
 142       fputs (HELP_OPTION_DESCRIPTION, stdout);
 143       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 144       fputs (_("\
 145 \n\
 146 Owner is unchanged if missing.  Group is unchanged if missing, but changed\n\
 147 to login group if implied by a `:' following a symbolic OWNER.\n\
 148 OWNER and GROUP may be numeric as well as symbolic.\n\
 149 "), stdout);
 150       printf (_("\
 151 \n\
 152 Examples:\n\
 153   %s root /u        Change the owner of /u to \"root\".\n\
 154   %s root:staff /u  Likewise, but also change its group to \"staff\".\n\
 155   %s -hR root /u    Change the owner of /u and subfiles to \"root\".\n\
 156 "),
 157               program_name, program_name, program_name);
 158       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 159     }
 160   exit (status);
 161 }
 162
 163 int
 164 main (int argc, char **argv)
 165 {
 166   bool preserve_root = false;
 167
 168   uid_t uid = -1;       /* Specified uid; -1 if not to be changed. */
 169   gid_t gid = -1;       /* Specified gid; -1 if not to be changed. */
 170
 171   /* Change the owner (group) of a file only if it has this uid (gid).
 172      -1 means there's no restriction.  */
 173   uid_t required_uid = -1;
 174   gid_t required_gid = -1;
 175
 176   /* Bit flags that control how fts works.  */
 177   int bit_flags = FTS_PHYSICAL;
 178
 179   /* 1 if --dereference, 0 if --no-dereference, -1 if neither has been
 180      specified.  */
 181   int dereference = -1;
 182
 183   struct Chown_option chopt;
 184   bool ok;
 185   int optc;
 186
 187   initialize_main (&argc, &argv);
 188   program_name = argv[0];
 189   setlocale (LC_ALL, "");
 190   bindtextdomain (PACKAGE, LOCALEDIR);
 191   textdomain (PACKAGE);
 192
 193   atexit (close_stdout);
 194
 195   chopt_init (&chopt);
 196
 197   while ((optc = getopt_long (argc, argv, "HLPRcfhv", long_options, NULL))
 198          != -1)
 199     {
 200       switch (optc)
 201         {
 202         case 'H': /* Traverse command-line symlinks-to-directories.  */
 203           bit_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
 204           break;
 205
 206         case 'L': /* Traverse all symlinks-to-directories.  */
 207           bit_flags = FTS_LOGICAL;
 208           break;
 209
 210         case 'P': /* Traverse no symlinks-to-directories.  */
 211           bit_flags = FTS_PHYSICAL;
 212           break;
 213
 214         case 'h': /* --no-dereference: affect symlinks */
 215           dereference = 0;
 216           break;
 217
 218         case DEREFERENCE_OPTION: /* --dereference: affect the referent
 219                                     of each symlink */
 220           dereference = 1;
 221           break;
 222
 223         case NO_PRESERVE_ROOT:
 224           preserve_root = false;
 225           break;
 226
 227         case PRESERVE_ROOT:
 228           preserve_root = true;
 229           break;
 230
 231         case REFERENCE_FILE_OPTION:
 232           reference_file = optarg;
 233           break;
 234
 235         case FROM_OPTION:
 236           {
 237             char *u_dummy, *g_dummy;
 238             const char *e = parse_user_spec (optarg,
 239                                              &required_uid, &required_gid,
 240                                              &u_dummy, &g_dummy);
 241             if (e)
 242               error (EXIT_FAILURE, 0, "%s: %s", quote (optarg), e);
 243             break;
 244           }
 245
 246         case 'R':
 247           chopt.recurse = true;
 248           break;
 249
 250         case 'c':
 251           chopt.verbosity = V_changes_only;
 252           break;
 253
 254         case 'f':
 255           chopt.force_silent = true;
 256           break;
 257
 258         case 'v':
 259           chopt.verbosity = V_high;
 260           break;
 261
 262         case_GETOPT_HELP_CHAR;
 263         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 264         default:
 265           usage (EXIT_FAILURE);
 266         }
 267     }
 268
 269   if (chopt.recurse)
 270     {
 271       if (bit_flags == FTS_PHYSICAL)
 272         {
 273           if (dereference == 1)
 274             error (EXIT_FAILURE, 0,
 275                    _("-R --dereference requires either -H or -L"));
 276           dereference = 0;
 277         }
 278     }
 279   else
 280     {
 281       bit_flags = FTS_PHYSICAL;
 282     }
 283   chopt.affect_symlink_referent = (dereference != 0);
 284
 285   if (argc - optind < (reference_file ? 1 : 2))
 286     {
 287       if (argc <= optind)
 288         error (0, 0, _("missing operand"));
 289       else
 290         error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
 291       usage (EXIT_FAILURE);
 292     }
 293
 294   if (reference_file)
 295     {
 296       struct stat ref_stats;
 297       if (stat (reference_file, &ref_stats))
 298         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 299                quote (reference_file));
 300
 301       uid = ref_stats.st_uid;
 302       gid = ref_stats.st_gid;
 303       chopt.user_name = uid_to_name (ref_stats.st_uid);
 304       chopt.group_name = gid_to_name (ref_stats.st_gid);
 305     }
 306   else
 307     {
 308       const char *e = parse_user_spec (argv[optind], &uid, &gid,
 309                                        &chopt.user_name, &chopt.group_name);
 310       if (e)
 311         error (EXIT_FAILURE, 0, "%s: %s", quote (argv[optind]), e);
 312
 313       /* If a group is specified but no user, set the user name to the
 314          empty string so that diagnostics say "ownership :GROUP"
 315          rather than "group GROUP".  */
 316       if (!chopt.user_name && chopt.group_name)
 317         chopt.user_name = "";
 318
 319       optind++;
 320     }
 321
 322   if (chopt.recurse & preserve_root)
 323     {
 324       static struct dev_ino dev_ino_buf;
 325       chopt.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 326       if (chopt.root_dev_ino == NULL)
 327         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 328                quote ("/"));
 329     }
 330
 331   ok = chown_files (argv + optind, bit_flags,
 332                     uid, gid,
 333                     required_uid, required_gid, &chopt);
 334
 335   chopt_free (&chopt);
 336
 337   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 338 }