src/chown.c

   1 /* chown, chgrp -- change user and group ownership of files
   2    Copyright (C) 1989-2024 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 <https://www.gnu.org/licenses/>.  */
  16
  17 /* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */
  18
  19 #include <config.h>
  20 #include <stdio.h>
  21 #include <sys/types.h>
  22 #include <getopt.h>
  23
  24 #include "system.h"
  25 #include "chown.h"
  26 #include "chown-core.h"
  27 #include "fts_.h"
  28 #include "quote.h"
  29 #include "root-dev-ino.h"
  30 #include "userspec.h"
  31
  32 /* The official name of this program (e.g., no 'g' prefix).  */
  33 #define PROGRAM_NAME (chown_mode == CHOWN_CHOWN ? "chown" : "chgrp")
  34
  35 #define AUTHORS \
  36   proper_name ("David MacKenzie"), \
  37   proper_name ("Jim Meyering")
  38
  39 /* The argument to the --reference option.  Use the owner and group IDs
  40    of this file.  This file must exist.  */
  41 static char *reference_file;
  42
  43 /* For long options that have no equivalent short option, use a
  44    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  45 enum
  46 {
  47   DEREFERENCE_OPTION = CHAR_MAX + 1,
  48   FROM_OPTION,
  49   NO_PRESERVE_ROOT,
  50   PRESERVE_ROOT,
  51   REFERENCE_FILE_OPTION
  52 };
  53
  54 static struct option const long_options[] =
  55 {
  56   {"recursive", no_argument, nullptr, 'R'},
  57   {"changes", no_argument, nullptr, 'c'},
  58   {"dereference", no_argument, nullptr, DEREFERENCE_OPTION},
  59   {"from", required_argument, nullptr, FROM_OPTION},
  60   {"no-dereference", no_argument, nullptr, 'h'},
  61   {"no-preserve-root", no_argument, nullptr, NO_PRESERVE_ROOT},
  62   {"preserve-root", no_argument, nullptr, PRESERVE_ROOT},
  63   {"quiet", no_argument, nullptr, 'f'},
  64   {"silent", no_argument, nullptr, 'f'},
  65   {"reference", required_argument, nullptr, REFERENCE_FILE_OPTION},
  66   {"verbose", no_argument, nullptr, 'v'},
  67   {GETOPT_HELP_OPTION_DECL},
  68   {GETOPT_VERSION_OPTION_DECL},
  69   {nullptr, 0, nullptr, 0}
  70 };
  71
  72 void
  73 usage (int status)
  74 {
  75   if (status != EXIT_SUCCESS)
  76     emit_try_help ();
  77   else
  78     {
  79       printf (_("\
  80 Usage: %s [OPTION]... %s FILE...\n\
  81   or:  %s [OPTION]... --reference=RFILE FILE...\n\
  82 "),
  83               program_name,
  84               chown_mode == CHOWN_CHOWN ? "[OWNER][:[GROUP]]" : "GROUP",
  85               program_name);
  86       if (chown_mode == CHOWN_CHOWN)
  87         fputs (_("\
  88 Change the owner and/or group of each FILE to OWNER and/or GROUP.\n\
  89 With --reference, change the owner and group of each FILE to those of RFILE.\n\
  90 \n\
  91 "), stdout);
  92       else
  93         fputs (_("\
  94 Change the group of each FILE to GROUP.\n\
  95 With --reference, change the group of each FILE to that of RFILE.\n\
  96 \n\
  97 "), stdout);
  98       fputs (_("\
  99   -c, --changes          like verbose but report only when a change is made\n\
 100   -f, --silent, --quiet  suppress most error messages\n\
 101   -v, --verbose          output a diagnostic for every file processed\n\
 102 "), stdout);
 103       fputs (_("\
 104       --dereference      affect the referent of each symbolic link (this is\n\
 105                          the default), rather than the symbolic link itself\n\
 106   -h, --no-dereference   affect symbolic links instead of any referenced file\n\
 107 "), stdout);
 108       fputs (_("\
 109                          (useful only on systems that can change the\n\
 110                          ownership of a symlink)\n\
 111 "), stdout);
 112       emit_from_option_description (chown_mode == CHOWN_CHOWN);
 113       fputs (_("\
 114       --no-preserve-root  do not treat '/' specially (the default)\n\
 115       --preserve-root    fail to operate recursively on '/'\n\
 116 "), stdout);
 117       fputs (_("\
 118       --reference=RFILE  use RFILE's ownership rather than specifying values\n\
 119                          RFILE is always dereferenced if a symbolic link.\n\
 120 "), stdout);
 121       fputs (_("\
 122   -R, --recursive        operate on files and directories recursively\n\
 123 "), stdout);
 124       fputs (_("\
 125 \n\
 126 The following options modify how a hierarchy is traversed when the -R\n\
 127 option is also specified.  If more than one is specified, only the final\n\
 128 one takes effect.\n\
 129 \n\
 130   -H                     if a command line argument is a symbolic link\n\
 131                          to a directory, traverse it\n\
 132   -L                     traverse every symbolic link to a directory\n\
 133                          encountered\n\
 134   -P                     do not traverse any symbolic links (default)\n\
 135 \n\
 136 "), stdout);
 137       fputs (HELP_OPTION_DESCRIPTION, stdout);
 138       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 139       if (chown_mode == CHOWN_CHOWN)
 140         fputs (_("\
 141 \n\
 142 Owner is unchanged if missing.  Group is unchanged if missing, but changed\n\
 143 to login group if implied by a ':' following a symbolic OWNER.\n\
 144 OWNER and GROUP may be numeric as well as symbolic.\n\
 145 "), stdout);
 146
 147       if (chown_mode == CHOWN_CHOWN)
 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       else
 157         printf (_("\
 158 \n\
 159 Examples:\n\
 160   %s staff /u      Change the group of /u to \"staff\".\n\
 161   %s -hR staff /u  Change the group of /u and subfiles to \"staff\".\n\
 162 "),
 163               program_name, program_name);
 164       emit_ancillary_info (PROGRAM_NAME);
 165     }
 166   exit (status);
 167 }
 168
 169 int
 170 main (int argc, char **argv)
 171 {
 172   bool preserve_root = false;
 173
 174   uid_t uid = -1;       /* Specified uid; -1 if not to be changed. */
 175   gid_t gid = -1;       /* Specified gid; -1 if not to be changed. */
 176
 177   /* Change the owner (group) of a file only if it has this uid (gid).
 178      -1 means there's no restriction.  */
 179   uid_t required_uid = -1;
 180   gid_t required_gid = -1;
 181
 182   /* Bit flags that control how fts works.  */
 183   int bit_flags = FTS_PHYSICAL;
 184
 185   /* 1 if --dereference, 0 if --no-dereference, -1 if neither has been
 186      specified.  */
 187   int dereference = -1;
 188
 189   struct Chown_option chopt;
 190   bool ok;
 191   int optc;
 192
 193   initialize_main (&argc, &argv);
 194   set_program_name (argv[0]);
 195   setlocale (LC_ALL, "");
 196   bindtextdomain (PACKAGE, LOCALEDIR);
 197   textdomain (PACKAGE);
 198
 199   atexit (close_stdout);
 200
 201   chopt_init (&chopt);
 202
 203   while ((optc = getopt_long (argc, argv, "HLPRcfhv", long_options, nullptr))
 204          != -1)
 205     {
 206       switch (optc)
 207         {
 208         case 'H': /* Traverse command-line symlinks-to-directories.  */
 209           bit_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
 210           break;
 211
 212         case 'L': /* Traverse all symlinks-to-directories.  */
 213           bit_flags = FTS_LOGICAL;
 214           break;
 215
 216         case 'P': /* Traverse no symlinks-to-directories.  */
 217           bit_flags = FTS_PHYSICAL;
 218           break;
 219
 220         case 'h': /* --no-dereference: affect symlinks */
 221           dereference = 0;
 222           break;
 223
 224         case DEREFERENCE_OPTION: /* --dereference: affect the referent
 225                                     of each symlink */
 226           dereference = 1;
 227           break;
 228
 229         case NO_PRESERVE_ROOT:
 230           preserve_root = false;
 231           break;
 232
 233         case PRESERVE_ROOT:
 234           preserve_root = true;
 235           break;
 236
 237         case REFERENCE_FILE_OPTION:
 238           reference_file = optarg;
 239           break;
 240
 241         case FROM_OPTION:
 242           {
 243             bool warn;
 244             char const *e = parse_user_spec_warn (optarg,
 245                                                   &required_uid, &required_gid,
 246                                                   nullptr, nullptr, &warn);
 247             if (e)
 248               error (warn ? 0 : EXIT_FAILURE, 0, "%s: %s", e, quote (optarg));
 249             break;
 250           }
 251
 252         case 'R':
 253           chopt.recurse = true;
 254           break;
 255
 256         case 'c':
 257           chopt.verbosity = V_changes_only;
 258           break;
 259
 260         case 'f':
 261           chopt.force_silent = true;
 262           break;
 263
 264         case 'v':
 265           chopt.verbosity = V_high;
 266           break;
 267
 268         case_GETOPT_HELP_CHAR;
 269         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 270         default:
 271           usage (EXIT_FAILURE);
 272         }
 273     }
 274
 275   if (chopt.recurse)
 276     {
 277       if (bit_flags == FTS_PHYSICAL)
 278         {
 279           if (dereference == 1)
 280             error (EXIT_FAILURE, 0,
 281                    _("-R --dereference requires either -H or -L"));
 282           dereference = 0;
 283         }
 284     }
 285   else
 286     {
 287       bit_flags = FTS_PHYSICAL;
 288     }
 289   chopt.affect_symlink_referent = (dereference != 0);
 290
 291   if (argc - optind < (reference_file ? 1 : 2))
 292     {
 293       if (argc <= optind)
 294         error (0, 0, _("missing operand"));
 295       else
 296         error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
 297       usage (EXIT_FAILURE);
 298     }
 299
 300   if (reference_file)
 301     {
 302       struct stat ref_stats;
 303       if (stat (reference_file, &ref_stats))
 304         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 305                quoteaf (reference_file));
 306
 307       if (chown_mode == CHOWN_CHOWN)
 308         {
 309           uid = ref_stats.st_uid;
 310           chopt.user_name = uid_to_name (ref_stats.st_uid);
 311         }
 312       gid = ref_stats.st_gid;
 313       chopt.group_name = gid_to_name (ref_stats.st_gid);
 314     }
 315   else
 316     {
 317       char *ug = argv[optind];
 318       if (chown_mode == CHOWN_CHGRP)
 319         {
 320           ug = xmalloc (1 + strlen (argv[optind]) + 1);
 321           stpcpy (stpcpy (ug, ":"), argv[optind]);
 322         }
 323
 324       bool warn;
 325       char const *e = parse_user_spec_warn (ug, &uid, &gid,
 326                                             &chopt.user_name,
 327                                             &chopt.group_name, &warn);
 328
 329       if (ug != argv[optind])
 330         free (ug);
 331
 332       if (e)
 333         error (warn ? 0 : EXIT_FAILURE, 0, "%s: %s", e, quote (argv[optind]));
 334
 335       /* If a group is specified but no user, set the user name to the
 336          empty string so that diagnostics say "ownership :GROUP"
 337          rather than "group GROUP".  */
 338       if (chown_mode == CHOWN_CHOWN && !chopt.user_name && chopt.group_name)
 339         chopt.user_name = xstrdup ("");
 340
 341       optind++;
 342     }
 343
 344   if (chopt.recurse && preserve_root)
 345     {
 346       static struct dev_ino dev_ino_buf;
 347       chopt.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 348       if (chopt.root_dev_ino == nullptr)
 349         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 350                quoteaf ("/"));
 351     }
 352
 353   bit_flags |= FTS_DEFER_STAT;
 354   ok = chown_files (argv + optind, bit_flags,
 355                     uid, gid,
 356                     required_uid, required_gid, &chopt);
 357
 358   main_exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 359 }