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 "lchown.h"
  41 #include "quote.h"
  42 #include "root-dev-ino.h"
  43 #include "userspec.h"
  44
  45 /* The official name of this program (e.g., no `g' prefix).  */
  46 #define PROGRAM_NAME "chown"
  47
  48 #define AUTHORS "David MacKenzie", "Jim Meyering"
  49
  50 /* The name the program was run with. */
  51 char *program_name;
  52
  53 /* The argument to the --reference option.  Use the owner and group IDs
  54    of this file.  This file must exist.  */
  55 static char *reference_file;
  56
  57 /* For long options that have no equivalent short option, use a
  58    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  59 enum
  60 {
  61   DEREFERENCE_OPTION = CHAR_MAX + 1,
  62   FROM_OPTION,
  63   NO_PRESERVE_ROOT,
  64   PRESERVE_ROOT,
  65   REFERENCE_FILE_OPTION
  66 };
  67
  68 static struct option const long_options[] =
  69 {
  70   {"recursive", no_argument, NULL, 'R'},
  71   {"changes", no_argument, NULL, 'c'},
  72   {"dereference", no_argument, NULL, DEREFERENCE_OPTION},
  73   {"from", required_argument, NULL, FROM_OPTION},
  74   {"no-dereference", no_argument, NULL, 'h'},
  75   {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
  76   {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
  77   {"quiet", no_argument, NULL, 'f'},
  78   {"silent", no_argument, NULL, 'f'},
  79   {"reference", required_argument, NULL, REFERENCE_FILE_OPTION},
  80   {"verbose", no_argument, NULL, 'v'},
  81   {GETOPT_HELP_OPTION_DECL},
  82   {GETOPT_VERSION_OPTION_DECL},
  83   {NULL, 0, NULL, 0}
  84 };
  85
  86 void
  87 usage (int status)
  88 {
  89   if (status != EXIT_SUCCESS)
  90     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  91              program_name);
  92   else
  93     {
  94       printf (_("\
  95 Usage: %s [OPTION]... [OWNER][:[GROUP]] FILE...\n\
  96   or:  %s [OPTION]... --reference=RFILE FILE...\n\
  97 "),
  98               program_name, program_name);
  99       fputs (_("\
 100 Change the owner and/or group of each FILE to OWNER and/or GROUP.\n\
 101 With --reference, change the owner and group of each FILE to those of RFILE.\n\
 102 \n\
 103   -c, --changes          like verbose but report only when a change is made\n\
 104       --dereference      affect the referent of each symbolic link (this is\n\
 105                          the default), rather than the symbolic link itself\n\
 106 "), stdout);
 107       fputs (_("\
 108   -h, --no-dereference   affect each symbolic link instead of any referenced\n\
 109                          file (useful only on systems that can change the\n\
 110                          ownership of a symlink)\n\
 111 "), stdout);
 112       fputs (_("\
 113       --from=CURRENT_OWNER:CURRENT_GROUP\n\
 114                          change the owner and/or group of each file only if\n\
 115                          its current owner and/or group match those specified\n\
 116                          here.  Either may be omitted, in which case a match\n\
 117                          is not required for the omitted attribute.\n\
 118 "), stdout);
 119       fputs (_("\
 120       --no-preserve-root  do not treat `/' specially (the default)\n\
 121       --preserve-root    fail to operate recursively on `/'\n\
 122 "), stdout);
 123       fputs (_("\
 124   -f, --silent, --quiet  suppress most error messages\n\
 125       --reference=RFILE  use RFILE's owner and group rather than\n\
 126                          specifying OWNER:GROUP values\n\
 127   -R, --recursive        operate on files and directories recursively\n\
 128   -v, --verbose          output a diagnostic for every file processed\n\
 129 \n\
 130 "), stdout);
 131       fputs (_("\
 132 The following options modify how a hierarchy is traversed when the -R\n\
 133 option is also specified.  If more than one is specified, only the final\n\
 134 one takes effect.\n\
 135 \n\
 136   -H                     if a command line argument is a symbolic link\n\
 137                          to a directory, traverse it\n\
 138   -L                     traverse every symbolic link to a directory\n\
 139                          encountered\n\
 140   -P                     do not traverse any symbolic links (default)\n\
 141 \n\
 142 "), stdout);
 143       fputs (HELP_OPTION_DESCRIPTION, stdout);
 144       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 145       fputs (_("\
 146 \n\
 147 Owner is unchanged if missing.  Group is unchanged if missing, but changed\n\
 148 to login group if implied by a `:' following a symbolic OWNER.\n\
 149 OWNER and GROUP may be numeric as well as symbolic.\n\
 150 "), stdout);
 151       printf (_("\
 152 \n\
 153 Examples:\n\
 154   %s root /u        Change the owner of /u to \"root\".\n\
 155   %s root:staff /u  Likewise, but also change its group to \"staff\".\n\
 156   %s -hR root /u    Change the owner of /u and subfiles to \"root\".\n\
 157 "),
 158               program_name, program_name, program_name);
 159       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 160     }
 161   exit (status);
 162 }
 163
 164 int
 165 main (int argc, char **argv)
 166 {
 167   bool preserve_root = false;
 168
 169   uid_t uid = -1;       /* Specified uid; -1 if not to be changed. */
 170   gid_t gid = -1;       /* Specified gid; -1 if not to be changed. */
 171
 172   /* Change the owner (group) of a file only if it has this uid (gid).
 173      -1 means there's no restriction.  */
 174   uid_t required_uid = -1;
 175   gid_t required_gid = -1;
 176
 177   /* Bit flags that control how fts works.  */
 178   int bit_flags = FTS_PHYSICAL;
 179
 180   /* 1 if --dereference, 0 if --no-dereference, -1 if neither has been
 181      specified.  */
 182   int dereference = -1;
 183
 184   struct Chown_option chopt;
 185   bool ok;
 186   int optc;
 187
 188   initialize_main (&argc, &argv);
 189   program_name = argv[0];
 190   setlocale (LC_ALL, "");
 191   bindtextdomain (PACKAGE, LOCALEDIR);
 192   textdomain (PACKAGE);
 193
 194   atexit (close_stdout);
 195
 196   chopt_init (&chopt);
 197
 198   while ((optc = getopt_long (argc, argv, "HLPRcfhv", long_options, NULL))
 199          != -1)
 200     {
 201       switch (optc)
 202         {
 203         case 'H': /* Traverse command-line symlinks-to-directories.  */
 204           bit_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
 205           break;
 206
 207         case 'L': /* Traverse all symlinks-to-directories.  */
 208           bit_flags = FTS_LOGICAL;
 209           break;
 210
 211         case 'P': /* Traverse no symlinks-to-directories.  */
 212           bit_flags = FTS_PHYSICAL;
 213           break;
 214
 215         case 'h': /* --no-dereference: affect symlinks */
 216           dereference = 0;
 217           break;
 218
 219         case DEREFERENCE_OPTION: /* --dereference: affect the referent
 220                                     of each symlink */
 221           dereference = 1;
 222           break;
 223
 224         case NO_PRESERVE_ROOT:
 225           preserve_root = false;
 226           break;
 227
 228         case PRESERVE_ROOT:
 229           preserve_root = true;
 230           break;
 231
 232         case REFERENCE_FILE_OPTION:
 233           reference_file = optarg;
 234           break;
 235
 236         case FROM_OPTION:
 237           {
 238             char *u_dummy, *g_dummy;
 239             const char *e = parse_user_spec (optarg,
 240                                              &required_uid, &required_gid,
 241                                              &u_dummy, &g_dummy);
 242             if (e)
 243               error (EXIT_FAILURE, 0, "%s: %s", quote (optarg), e);
 244             break;
 245           }
 246
 247         case 'R':
 248           chopt.recurse = true;
 249           break;
 250
 251         case 'c':
 252           chopt.verbosity = V_changes_only;
 253           break;
 254
 255         case 'f':
 256           chopt.force_silent = true;
 257           break;
 258
 259         case 'v':
 260           chopt.verbosity = V_high;
 261           break;
 262
 263         case_GETOPT_HELP_CHAR;
 264         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 265         default:
 266           usage (EXIT_FAILURE);
 267         }
 268     }
 269
 270   if (chopt.recurse)
 271     {
 272       if (bit_flags == FTS_PHYSICAL)
 273         {
 274           if (dereference == 1)
 275             error (EXIT_FAILURE, 0,
 276                    _("-R --dereference requires either -H or -L"));
 277           chopt.affect_symlink_referent = false;
 278         }
 279       else
 280         {
 281           if (dereference == 0)
 282             error (EXIT_FAILURE, 0, _("-R -h requires -P"));
 283           chopt.affect_symlink_referent = true;
 284         }
 285     }
 286   else
 287     {
 288       bit_flags = FTS_PHYSICAL;
 289       chopt.affect_symlink_referent = (dereference != 0);
 290     }
 291
 292   if (argc - optind < (reference_file ? 1 : 2))
 293     {
 294       if (argc <= optind)
 295         error (0, 0, _("missing operand"));
 296       else
 297         error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
 298       usage (EXIT_FAILURE);
 299     }
 300
 301   if (reference_file)
 302     {
 303       struct stat ref_stats;
 304       if (stat (reference_file, &ref_stats))
 305         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 306                quote (reference_file));
 307
 308       uid = ref_stats.st_uid;
 309       gid = ref_stats.st_gid;
 310       chopt.user_name = uid_to_name (ref_stats.st_uid);
 311       chopt.group_name = gid_to_name (ref_stats.st_gid);
 312     }
 313   else
 314     {
 315       const char *e = parse_user_spec (argv[optind], &uid, &gid,
 316                                        &chopt.user_name, &chopt.group_name);
 317       if (e)
 318         error (EXIT_FAILURE, 0, "%s: %s", quote (argv[optind]), e);
 319
 320       /* If a group is specified but no user, set the user name to the
 321          empty string so that diagnostics say "ownership :GROUP"
 322          rather than "group GROUP".  */
 323       if (!chopt.user_name && chopt.group_name)
 324         chopt.user_name = "";
 325
 326       optind++;
 327     }
 328
 329   if (chopt.recurse & preserve_root)
 330     {
 331       static struct dev_ino dev_ino_buf;
 332       chopt.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 333       if (chopt.root_dev_ino == NULL)
 334         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 335                quote ("/"));
 336     }
 337
 338   ok = chown_files (argv + optind, bit_flags,
 339                     uid, gid,
 340                     required_uid, required_gid, &chopt);
 341
 342   chopt_free (&chopt);
 343
 344   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 345 }