src/chgrp.c

   1 /* chgrp -- change 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 /* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */
  19
  20 #include <config.h>
  21 #include <stdio.h>
  22 #include <sys/types.h>
  23 #include <grp.h>
  24 #include <getopt.h>
  25
  26 #include "system.h"
  27 #include "chown-core.h"
  28 #include "error.h"
  29 #include "fts_.h"
  30 #include "group-member.h"
  31 #include "quote.h"
  32 #include "root-dev-ino.h"
  33 #include "xstrtol.h"
  34
  35 /* The official name of this program (e.g., no `g' prefix).  */
  36 #define PROGRAM_NAME "chgrp"
  37
  38 #define AUTHORS "David MacKenzie", "Jim Meyering"
  39
  40 #if ! HAVE_ENDGRENT
  41 # define endgrent() ((void) 0)
  42 #endif
  43
  44 /* The name the program was run with. */
  45 char *program_name;
  46
  47 /* The argument to the --reference option.  Use the group ID of this file.
  48    This file must exist.  */
  49 static char *reference_file;
  50
  51 /* For long options that have no equivalent short option, use a
  52    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  53 enum
  54 {
  55   DEREFERENCE_OPTION = CHAR_MAX + 1,
  56   NO_PRESERVE_ROOT,
  57   PRESERVE_ROOT,
  58   REFERENCE_FILE_OPTION
  59 };
  60
  61 static struct option const long_options[] =
  62 {
  63   {"recursive", no_argument, NULL, 'R'},
  64   {"changes", no_argument, NULL, 'c'},
  65   {"dereference", no_argument, NULL, DEREFERENCE_OPTION},
  66   {"no-dereference", no_argument, NULL, 'h'},
  67   {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
  68   {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
  69   {"quiet", no_argument, NULL, 'f'},
  70   {"silent", no_argument, NULL, 'f'},
  71   {"reference", required_argument, NULL, REFERENCE_FILE_OPTION},
  72   {"verbose", no_argument, NULL, 'v'},
  73   {GETOPT_HELP_OPTION_DECL},
  74   {GETOPT_VERSION_OPTION_DECL},
  75   {NULL, 0, NULL, 0}
  76 };
  77
  78 /* Return the group ID of NAME, or -1 if no name was specified.  */
  79
  80 static gid_t
  81 parse_group (const char *name)
  82 {
  83   gid_t gid = -1;
  84
  85   if (*name)
  86     {
  87       struct group *grp = getgrnam (name);
  88       if (grp)
  89         gid = grp->gr_gid;
  90       else
  91         {
  92           unsigned long int tmp;
  93           if (! (xstrtoul (name, NULL, 10, &tmp, "") == LONGINT_OK
  94                  && tmp <= GID_T_MAX))
  95             error (EXIT_FAILURE, 0, _("invalid group %s"), quote (name));
  96           gid = tmp;
  97         }
  98       endgrent ();              /* Save a file descriptor. */
  99     }
 100
 101   return gid;
 102 }
 103
 104 void
 105 usage (int status)
 106 {
 107   if (status != EXIT_SUCCESS)
 108     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 109              program_name);
 110   else
 111     {
 112       printf (_("\
 113 Usage: %s [OPTION]... GROUP FILE...\n\
 114   or:  %s [OPTION]... --reference=RFILE FILE...\n\
 115 "),
 116               program_name, program_name);
 117       fputs (_("\
 118 Change the group of each FILE to GROUP.\n\
 119 With --reference, change the group of each FILE to that of RFILE.\n\
 120 \n\
 121   -c, --changes          like verbose but report only when a change is made\n\
 122       --dereference      affect the referent of each symbolic link (this is\n\
 123                          the default), rather than the symbolic link itself\n\
 124 "), stdout);
 125       fputs (_("\
 126   -h, --no-dereference   affect each symbolic link instead of any referenced\n\
 127                          file (useful only on systems that can change the\n\
 128                          ownership of a symlink)\n\
 129 "), stdout);
 130       fputs (_("\
 131       --no-preserve-root  do not treat `/' specially (the default)\n\
 132       --preserve-root    fail to operate recursively on `/'\n\
 133 "), stdout);
 134       fputs (_("\
 135   -f, --silent, --quiet  suppress most error messages\n\
 136       --reference=RFILE  use RFILE's group rather than specifying a\n\
 137                          GROUP value\n\
 138   -R, --recursive        operate on files and directories recursively\n\
 139   -v, --verbose          output a diagnostic for every file processed\n\
 140 \n\
 141 "), stdout);
 142       fputs (_("\
 143 The following options modify how a hierarchy is traversed when the -R\n\
 144 option is also specified.  If more than one is specified, only the final\n\
 145 one takes effect.\n\
 146 \n\
 147   -H                     if a command line argument is a symbolic link\n\
 148                          to a directory, traverse it\n\
 149   -L                     traverse every symbolic link to a directory\n\
 150                          encountered\n\
 151   -P                     do not traverse any symbolic links (default)\n\
 152 \n\
 153 "), stdout);
 154       fputs (HELP_OPTION_DESCRIPTION, stdout);
 155       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 156       printf (_("\
 157 \n\
 158 Examples:\n\
 159   %s staff /u      Change the group of /u to \"staff\".\n\
 160   %s -hR staff /u  Change the group of /u and subfiles to \"staff\".\n\
 161 "),
 162               program_name, program_name);
 163       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 164     }
 165   exit (status);
 166 }
 167
 168 int
 169 main (int argc, char **argv)
 170 {
 171   bool preserve_root = false;
 172   gid_t gid;
 173
 174   /* Bit flags that control how fts works.  */
 175   int bit_flags = FTS_PHYSICAL;
 176
 177   /* 1 if --dereference, 0 if --no-dereference, -1 if neither has been
 178      specified.  */
 179   int dereference = -1;
 180
 181   struct Chown_option chopt;
 182   bool ok;
 183   int optc;
 184
 185   initialize_main (&argc, &argv);
 186   program_name = argv[0];
 187   setlocale (LC_ALL, "");
 188   bindtextdomain (PACKAGE, LOCALEDIR);
 189   textdomain (PACKAGE);
 190
 191   atexit (close_stdout);
 192
 193   chopt_init (&chopt);
 194
 195   while ((optc = getopt_long (argc, argv, "HLPRcfhv", long_options, NULL))
 196          != -1)
 197     {
 198       switch (optc)
 199         {
 200         case 'H': /* Traverse command-line symlinks-to-directories.  */
 201           bit_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
 202           break;
 203
 204         case 'L': /* Traverse all symlinks-to-directories.  */
 205           bit_flags = FTS_LOGICAL;
 206           break;
 207
 208         case 'P': /* Traverse no symlinks-to-directories.  */
 209           bit_flags = FTS_PHYSICAL;
 210           break;
 211
 212         case 'h': /* --no-dereference: affect symlinks */
 213           dereference = 0;
 214           break;
 215
 216         case DEREFERENCE_OPTION: /* --dereference: affect the referent
 217                                     of each symlink */
 218           dereference = 1;
 219           break;
 220
 221         case NO_PRESERVE_ROOT:
 222           preserve_root = false;
 223           break;
 224
 225         case PRESERVE_ROOT:
 226           preserve_root = true;
 227           break;
 228
 229         case REFERENCE_FILE_OPTION:
 230           reference_file = optarg;
 231           break;
 232
 233         case 'R':
 234           chopt.recurse = true;
 235           break;
 236
 237         case 'c':
 238           chopt.verbosity = V_changes_only;
 239           break;
 240
 241         case 'f':
 242           chopt.force_silent = true;
 243           break;
 244
 245         case 'v':
 246           chopt.verbosity = V_high;
 247           break;
 248
 249         case_GETOPT_HELP_CHAR;
 250         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 251         default:
 252           usage (EXIT_FAILURE);
 253         }
 254     }
 255
 256   if (chopt.recurse)
 257     {
 258       if (bit_flags == FTS_PHYSICAL)
 259         {
 260           if (dereference == 1)
 261             error (EXIT_FAILURE, 0,
 262                    _("-R --dereference requires either -H or -L"));
 263           dereference = 0;
 264         }
 265     }
 266   else
 267     {
 268       bit_flags = FTS_PHYSICAL;
 269     }
 270   chopt.affect_symlink_referent = (dereference != 0);
 271
 272   if (argc - optind < (reference_file ? 1 : 2))
 273     {
 274       if (argc <= optind)
 275         error (0, 0, _("missing operand"));
 276       else
 277         error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
 278       usage (EXIT_FAILURE);
 279     }
 280
 281   if (reference_file)
 282     {
 283       struct stat ref_stats;
 284       if (stat (reference_file, &ref_stats))
 285         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 286                quote (reference_file));
 287
 288       gid = ref_stats.st_gid;
 289       chopt.group_name = gid_to_name (ref_stats.st_gid);
 290     }
 291   else
 292     {
 293       char *group_name = argv[optind++];
 294       chopt.group_name = (*group_name ? group_name : NULL);
 295       gid = parse_group (group_name);
 296     }
 297
 298   if (chopt.recurse & preserve_root)
 299     {
 300       static struct dev_ino dev_ino_buf;
 301       chopt.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 302       if (chopt.root_dev_ino == NULL)
 303         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 304                quote ("/"));
 305     }
 306
 307   ok = chown_files (argv + optind, bit_flags,
 308                     (uid_t) -1, gid,
 309                     (uid_t) -1, (gid_t) -1, &chopt);
 310
 311   chopt_free (&chopt);
 312
 313   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 314 }