src/chgrp.c

   1 /* chgrp -- change group ownership of files
   2    Copyright (C) 1989-1991, 1995-2011 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 /* 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 <grp.h>
  23 #include <getopt.h>
  24
  25 #include "system.h"
  26 #include "chown-core.h"
  27 #include "error.h"
  28 #include "fts_.h"
  29 #include "quote.h"
  30 #include "root-dev-ino.h"
  31 #include "xstrtol.h"
  32
  33 /* The official name of this program (e.g., no `g' prefix).  */
  34 #define PROGRAM_NAME "chgrp"
  35
  36 #define AUTHORS \
  37   proper_name ("David MacKenzie"), \
  38   proper_name ("Jim Meyering")
  39
  40 #if ! HAVE_ENDGRENT
  41 # define endgrent() ((void) 0)
  42 #endif
  43
  44 /* The argument to the --reference option.  Use the group ID of this file.
  45    This file must exist.  */
  46 static char *reference_file;
  47
  48 /* For long options that have no equivalent short option, use a
  49    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  50 enum
  51 {
  52   DEREFERENCE_OPTION = CHAR_MAX + 1,
  53   NO_PRESERVE_ROOT,
  54   PRESERVE_ROOT,
  55   REFERENCE_FILE_OPTION
  56 };
  57
  58 static struct option const long_options[] =
  59 {
  60   {"recursive", no_argument, NULL, 'R'},
  61   {"changes", no_argument, NULL, 'c'},
  62   {"dereference", no_argument, NULL, DEREFERENCE_OPTION},
  63   {"no-dereference", no_argument, NULL, 'h'},
  64   {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
  65   {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
  66   {"quiet", no_argument, NULL, 'f'},
  67   {"silent", no_argument, NULL, 'f'},
  68   {"reference", required_argument, NULL, REFERENCE_FILE_OPTION},
  69   {"verbose", no_argument, NULL, 'v'},
  70   {GETOPT_HELP_OPTION_DECL},
  71   {GETOPT_VERSION_OPTION_DECL},
  72   {NULL, 0, NULL, 0}
  73 };
  74
  75 /* Return the group ID of NAME, or -1 if no name was specified.  */
  76
  77 static gid_t
  78 parse_group (const char *name)
  79 {
  80   gid_t gid = -1;
  81
  82   if (*name)
  83     {
  84       struct group *grp = getgrnam (name);
  85       if (grp)
  86         gid = grp->gr_gid;
  87       else
  88         {
  89           unsigned long int tmp;
  90           if (! (xstrtoul (name, NULL, 10, &tmp, "") == LONGINT_OK
  91                  && tmp <= GID_T_MAX))
  92             error (EXIT_FAILURE, 0, _("invalid group: %s"), quote (name));
  93           gid = tmp;
  94         }
  95       endgrent ();              /* Save a file descriptor. */
  96     }
  97
  98   return gid;
  99 }
 100
 101 void
 102 usage (int status)
 103 {
 104   if (status != EXIT_SUCCESS)
 105     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 106              program_name);
 107   else
 108     {
 109       printf (_("\
 110 Usage: %s [OPTION]... GROUP FILE...\n\
 111   or:  %s [OPTION]... --reference=RFILE FILE...\n\
 112 "),
 113               program_name, program_name);
 114       fputs (_("\
 115 Change the group of each FILE to GROUP.\n\
 116 With --reference, change the group of each FILE to that of RFILE.\n\
 117 \n\
 118   -c, --changes          like verbose but report only when a change is made\n\
 119       --dereference      affect the referent of each symbolic link (this is\n\
 120                          the default), rather than the symbolic link itself\n\
 121 "), stdout);
 122       fputs (_("\
 123   -h, --no-dereference   affect each symbolic link instead of any referenced\n\
 124                          file (useful only on systems that can change the\n\
 125                          ownership of a symlink)\n\
 126 "), stdout);
 127       fputs (_("\
 128       --no-preserve-root  do not treat `/' specially (the default)\n\
 129       --preserve-root    fail to operate recursively on `/'\n\
 130 "), stdout);
 131       fputs (_("\
 132   -f, --silent, --quiet  suppress most error messages\n\
 133       --reference=RFILE  use RFILE's group rather than specifying a\n\
 134                          GROUP value\n\
 135   -R, --recursive        operate on files and directories recursively\n\
 136   -v, --verbose          output a diagnostic for every file processed\n\
 137 \n\
 138 "), stdout);
 139       fputs (_("\
 140 The following options modify how a hierarchy is traversed when the -R\n\
 141 option is also specified.  If more than one is specified, only the final\n\
 142 one takes effect.\n\
 143 \n\
 144   -H                     if a command line argument is a symbolic link\n\
 145                          to a directory, traverse it\n\
 146   -L                     traverse every symbolic link to a directory\n\
 147                          encountered\n\
 148   -P                     do not traverse any symbolic links (default)\n\
 149 \n\
 150 "), stdout);
 151       fputs (HELP_OPTION_DESCRIPTION, stdout);
 152       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 153       printf (_("\
 154 \n\
 155 Examples:\n\
 156   %s staff /u      Change the group of /u to \"staff\".\n\
 157   %s -hR staff /u  Change the group of /u and subfiles to \"staff\".\n\
 158 "),
 159               program_name, program_name);
 160       emit_ancillary_info ();
 161     }
 162   exit (status);
 163 }
 164
 165 int
 166 main (int argc, char **argv)
 167 {
 168   bool preserve_root = false;
 169   gid_t gid;
 170
 171   /* Bit flags that control how fts works.  */
 172   int bit_flags = FTS_PHYSICAL;
 173
 174   /* 1 if --dereference, 0 if --no-dereference, -1 if neither has been
 175      specified.  */
 176   int dereference = -1;
 177
 178   struct Chown_option chopt;
 179   bool ok;
 180   int optc;
 181
 182   initialize_main (&argc, &argv);
 183   set_program_name (argv[0]);
 184   setlocale (LC_ALL, "");
 185   bindtextdomain (PACKAGE, LOCALEDIR);
 186   textdomain (PACKAGE);
 187
 188   atexit (close_stdout);
 189
 190   chopt_init (&chopt);
 191
 192   while ((optc = getopt_long (argc, argv, "HLPRcfhv", long_options, NULL))
 193          != -1)
 194     {
 195       switch (optc)
 196         {
 197         case 'H': /* Traverse command-line symlinks-to-directories.  */
 198           bit_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
 199           break;
 200
 201         case 'L': /* Traverse all symlinks-to-directories.  */
 202           bit_flags = FTS_LOGICAL;
 203           break;
 204
 205         case 'P': /* Traverse no symlinks-to-directories.  */
 206           bit_flags = FTS_PHYSICAL;
 207           break;
 208
 209         case 'h': /* --no-dereference: affect symlinks */
 210           dereference = 0;
 211           break;
 212
 213         case DEREFERENCE_OPTION: /* --dereference: affect the referent
 214                                     of each symlink */
 215           dereference = 1;
 216           break;
 217
 218         case NO_PRESERVE_ROOT:
 219           preserve_root = false;
 220           break;
 221
 222         case PRESERVE_ROOT:
 223           preserve_root = true;
 224           break;
 225
 226         case REFERENCE_FILE_OPTION:
 227           reference_file = optarg;
 228           break;
 229
 230         case 'R':
 231           chopt.recurse = true;
 232           break;
 233
 234         case 'c':
 235           chopt.verbosity = V_changes_only;
 236           break;
 237
 238         case 'f':
 239           chopt.force_silent = true;
 240           break;
 241
 242         case 'v':
 243           chopt.verbosity = V_high;
 244           break;
 245
 246         case_GETOPT_HELP_CHAR;
 247         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 248         default:
 249           usage (EXIT_FAILURE);
 250         }
 251     }
 252
 253   if (chopt.recurse)
 254     {
 255       if (bit_flags == FTS_PHYSICAL)
 256         {
 257           if (dereference == 1)
 258             error (EXIT_FAILURE, 0,
 259                    _("-R --dereference requires either -H or -L"));
 260           dereference = 0;
 261         }
 262     }
 263   else
 264     {
 265       bit_flags = FTS_PHYSICAL;
 266     }
 267   chopt.affect_symlink_referent = (dereference != 0);
 268
 269   if (argc - optind < (reference_file ? 1 : 2))
 270     {
 271       if (argc <= optind)
 272         error (0, 0, _("missing operand"));
 273       else
 274         error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
 275       usage (EXIT_FAILURE);
 276     }
 277
 278   if (reference_file)
 279     {
 280       struct stat ref_stats;
 281       if (stat (reference_file, &ref_stats))
 282         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 283                quote (reference_file));
 284
 285       gid = ref_stats.st_gid;
 286       chopt.group_name = gid_to_name (ref_stats.st_gid);
 287     }
 288   else
 289     {
 290       char *group_name = argv[optind++];
 291       chopt.group_name = (*group_name ? group_name : NULL);
 292       gid = parse_group (group_name);
 293     }
 294
 295   if (chopt.recurse && preserve_root)
 296     {
 297       static struct dev_ino dev_ino_buf;
 298       chopt.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 299       if (chopt.root_dev_ino == NULL)
 300         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 301                quote ("/"));
 302     }
 303
 304   bit_flags |= FTS_DEFER_STAT;
 305   ok = chown_files (argv + optind, bit_flags,
 306                     (uid_t) -1, gid,
 307                     (uid_t) -1, (gid_t) -1, &chopt);
 308
 309   chopt_free (&chopt);
 310
 311   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 312 }