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 "group-member.h"
  30 #include "quote.h"
  31 #include "root-dev-ino.h"
  32 #include "xstrtol.h"
  33
  34 /* The official name of this program (e.g., no `g' prefix).  */
  35 #define PROGRAM_NAME "chgrp"
  36
  37 #define AUTHORS \
  38   proper_name ("David MacKenzie"), \
  39   proper_name ("Jim Meyering")
  40
  41 #if ! HAVE_ENDGRENT
  42 # define endgrent() ((void) 0)
  43 #endif
  44
  45 /* The argument to the --reference option.  Use the group ID of this file.
  46    This file must exist.  */
  47 static char *reference_file;
  48
  49 /* For long options that have no equivalent short option, use a
  50    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  51 enum
  52 {
  53   DEREFERENCE_OPTION = CHAR_MAX + 1,
  54   NO_PRESERVE_ROOT,
  55   PRESERVE_ROOT,
  56   REFERENCE_FILE_OPTION
  57 };
  58
  59 static struct option const long_options[] =
  60 {
  61   {"recursive", no_argument, NULL, 'R'},
  62   {"changes", no_argument, NULL, 'c'},
  63   {"dereference", no_argument, NULL, DEREFERENCE_OPTION},
  64   {"no-dereference", no_argument, NULL, 'h'},
  65   {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
  66   {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
  67   {"quiet", no_argument, NULL, 'f'},
  68   {"silent", no_argument, NULL, 'f'},
  69   {"reference", required_argument, NULL, REFERENCE_FILE_OPTION},
  70   {"verbose", no_argument, NULL, 'v'},
  71   {GETOPT_HELP_OPTION_DECL},
  72   {GETOPT_VERSION_OPTION_DECL},
  73   {NULL, 0, NULL, 0}
  74 };
  75
  76 /* Return the group ID of NAME, or -1 if no name was specified.  */
  77
  78 static gid_t
  79 parse_group (const char *name)
  80 {
  81   gid_t gid = -1;
  82
  83   if (*name)
  84     {
  85       struct group *grp = getgrnam (name);
  86       if (grp)
  87         gid = grp->gr_gid;
  88       else
  89         {
  90           unsigned long int tmp;
  91           if (! (xstrtoul (name, NULL, 10, &tmp, "") == LONGINT_OK
  92                  && tmp <= GID_T_MAX))
  93             error (EXIT_FAILURE, 0, _("invalid group: %s"), quote (name));
  94           gid = tmp;
  95         }
  96       endgrent ();              /* Save a file descriptor. */
  97     }
  98
  99   return gid;
 100 }
 101
 102 void
 103 usage (int status)
 104 {
 105   if (status != EXIT_SUCCESS)
 106     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 107              program_name);
 108   else
 109     {
 110       printf (_("\
 111 Usage: %s [OPTION]... GROUP FILE...\n\
 112   or:  %s [OPTION]... --reference=RFILE FILE...\n\
 113 "),
 114               program_name, program_name);
 115       fputs (_("\
 116 Change the group of each FILE to GROUP.\n\
 117 With --reference, change the group of each FILE to that of RFILE.\n\
 118 \n\
 119   -c, --changes          like verbose but report only when a change is made\n\
 120       --dereference      affect the referent of each symbolic link (this is\n\
 121                          the default), rather than the symbolic link itself\n\
 122 "), stdout);
 123       fputs (_("\
 124   -h, --no-dereference   affect each symbolic link instead of any referenced\n\
 125                          file (useful only on systems that can change the\n\
 126                          ownership of a symlink)\n\
 127 "), stdout);
 128       fputs (_("\
 129       --no-preserve-root  do not treat `/' specially (the default)\n\
 130       --preserve-root    fail to operate recursively on `/'\n\
 131 "), stdout);
 132       fputs (_("\
 133   -f, --silent, --quiet  suppress most error messages\n\
 134       --reference=RFILE  use RFILE's group rather than specifying a\n\
 135                          GROUP value\n\
 136   -R, --recursive        operate on files and directories recursively\n\
 137   -v, --verbose          output a diagnostic for every file processed\n\
 138 \n\
 139 "), stdout);
 140       fputs (_("\
 141 The following options modify how a hierarchy is traversed when the -R\n\
 142 option is also specified.  If more than one is specified, only the final\n\
 143 one takes effect.\n\
 144 \n\
 145   -H                     if a command line argument is a symbolic link\n\
 146                          to a directory, traverse it\n\
 147   -L                     traverse every symbolic link to a directory\n\
 148                          encountered\n\
 149   -P                     do not traverse any symbolic links (default)\n\
 150 \n\
 151 "), stdout);
 152       fputs (HELP_OPTION_DESCRIPTION, stdout);
 153       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 154       printf (_("\
 155 \n\
 156 Examples:\n\
 157   %s staff /u      Change the group of /u to \"staff\".\n\
 158   %s -hR staff /u  Change the group of /u and subfiles to \"staff\".\n\
 159 "),
 160               program_name, program_name);
 161       emit_ancillary_info ();
 162     }
 163   exit (status);
 164 }
 165
 166 int
 167 main (int argc, char **argv)
 168 {
 169   bool preserve_root = false;
 170   gid_t gid;
 171
 172   /* Bit flags that control how fts works.  */
 173   int bit_flags = FTS_PHYSICAL;
 174
 175   /* 1 if --dereference, 0 if --no-dereference, -1 if neither has been
 176      specified.  */
 177   int dereference = -1;
 178
 179   struct Chown_option chopt;
 180   bool ok;
 181   int optc;
 182
 183   initialize_main (&argc, &argv);
 184   set_program_name (argv[0]);
 185   setlocale (LC_ALL, "");
 186   bindtextdomain (PACKAGE, LOCALEDIR);
 187   textdomain (PACKAGE);
 188
 189   atexit (close_stdout);
 190
 191   chopt_init (&chopt);
 192
 193   while ((optc = getopt_long (argc, argv, "HLPRcfhv", long_options, NULL))
 194          != -1)
 195     {
 196       switch (optc)
 197         {
 198         case 'H': /* Traverse command-line symlinks-to-directories.  */
 199           bit_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
 200           break;
 201
 202         case 'L': /* Traverse all symlinks-to-directories.  */
 203           bit_flags = FTS_LOGICAL;
 204           break;
 205
 206         case 'P': /* Traverse no symlinks-to-directories.  */
 207           bit_flags = FTS_PHYSICAL;
 208           break;
 209
 210         case 'h': /* --no-dereference: affect symlinks */
 211           dereference = 0;
 212           break;
 213
 214         case DEREFERENCE_OPTION: /* --dereference: affect the referent
 215                                     of each symlink */
 216           dereference = 1;
 217           break;
 218
 219         case NO_PRESERVE_ROOT:
 220           preserve_root = false;
 221           break;
 222
 223         case PRESERVE_ROOT:
 224           preserve_root = true;
 225           break;
 226
 227         case REFERENCE_FILE_OPTION:
 228           reference_file = optarg;
 229           break;
 230
 231         case 'R':
 232           chopt.recurse = true;
 233           break;
 234
 235         case 'c':
 236           chopt.verbosity = V_changes_only;
 237           break;
 238
 239         case 'f':
 240           chopt.force_silent = true;
 241           break;
 242
 243         case 'v':
 244           chopt.verbosity = V_high;
 245           break;
 246
 247         case_GETOPT_HELP_CHAR;
 248         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 249         default:
 250           usage (EXIT_FAILURE);
 251         }
 252     }
 253
 254   if (chopt.recurse)
 255     {
 256       if (bit_flags == FTS_PHYSICAL)
 257         {
 258           if (dereference == 1)
 259             error (EXIT_FAILURE, 0,
 260                    _("-R --dereference requires either -H or -L"));
 261           dereference = 0;
 262         }
 263     }
 264   else
 265     {
 266       bit_flags = FTS_PHYSICAL;
 267     }
 268   chopt.affect_symlink_referent = (dereference != 0);
 269
 270   if (argc - optind < (reference_file ? 1 : 2))
 271     {
 272       if (argc <= optind)
 273         error (0, 0, _("missing operand"));
 274       else
 275         error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
 276       usage (EXIT_FAILURE);
 277     }
 278
 279   if (reference_file)
 280     {
 281       struct stat ref_stats;
 282       if (stat (reference_file, &ref_stats))
 283         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 284                quote (reference_file));
 285
 286       gid = ref_stats.st_gid;
 287       chopt.group_name = gid_to_name (ref_stats.st_gid);
 288     }
 289   else
 290     {
 291       char *group_name = argv[optind++];
 292       chopt.group_name = (*group_name ? group_name : NULL);
 293       gid = parse_group (group_name);
 294     }
 295
 296   if (chopt.recurse && preserve_root)
 297     {
 298       static struct dev_ino dev_ino_buf;
 299       chopt.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 300       if (chopt.root_dev_ino == NULL)
 301         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 302                quote ("/"));
 303     }
 304
 305   bit_flags |= FTS_DEFER_STAT;
 306   ok = chown_files (argv + optind, bit_flags,
 307                     (uid_t) -1, gid,
 308                     (uid_t) -1, (gid_t) -1, &chopt);
 309
 310   chopt_free (&chopt);
 311
 312   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 313 }