src/chgrp.c

   1 /* chgrp -- change group ownership of files
   2    Copyright (C) 89, 90, 91, 1995-2007 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 "David MacKenzie", "Jim Meyering"
  38
  39 #if ! HAVE_ENDGRENT
  40 # define endgrent() ((void) 0)
  41 #endif
  42
  43 /* The name the program was run with. */
  44 char *program_name;
  45
  46 /* The argument to the --reference option.  Use the group ID of this file.
  47    This file must exist.  */
  48 static char *reference_file;
  49
  50 /* For long options that have no equivalent short option, use a
  51    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  52 enum
  53 {
  54   DEREFERENCE_OPTION = CHAR_MAX + 1,
  55   NO_PRESERVE_ROOT,
  56   PRESERVE_ROOT,
  57   REFERENCE_FILE_OPTION
  58 };
  59
  60 static struct option const long_options[] =
  61 {
  62   {"recursive", no_argument, NULL, 'R'},
  63   {"changes", no_argument, NULL, 'c'},
  64   {"dereference", no_argument, NULL, DEREFERENCE_OPTION},
  65   {"no-dereference", no_argument, NULL, 'h'},
  66   {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
  67   {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
  68   {"quiet", no_argument, NULL, 'f'},
  69   {"silent", no_argument, NULL, 'f'},
  70   {"reference", required_argument, NULL, REFERENCE_FILE_OPTION},
  71   {"verbose", no_argument, NULL, 'v'},
  72   {GETOPT_HELP_OPTION_DECL},
  73   {GETOPT_VERSION_OPTION_DECL},
  74   {NULL, 0, NULL, 0}
  75 };
  76
  77 /* Return the group ID of NAME, or -1 if no name was specified.  */
  78
  79 static gid_t
  80 parse_group (const char *name)
  81 {
  82   gid_t gid = -1;
  83
  84   if (*name)
  85     {
  86       struct group *grp = getgrnam (name);
  87       if (grp)
  88         gid = grp->gr_gid;
  89       else
  90         {
  91           unsigned long int tmp;
  92           if (! (xstrtoul (name, NULL, 10, &tmp, "") == LONGINT_OK
  93                  && tmp <= GID_T_MAX))
  94             error (EXIT_FAILURE, 0, _("invalid group: %s"), quote (name));
  95           gid = tmp;
  96         }
  97       endgrent ();              /* Save a file descriptor. */
  98     }
  99
 100   return gid;
 101 }
 102
 103 void
 104 usage (int status)
 105 {
 106   if (status != EXIT_SUCCESS)
 107     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 108              program_name);
 109   else
 110     {
 111       printf (_("\
 112 Usage: %s [OPTION]... GROUP FILE...\n\
 113   or:  %s [OPTION]... --reference=RFILE FILE...\n\
 114 "),
 115               program_name, program_name);
 116       fputs (_("\
 117 Change the group of each FILE to GROUP.\n\
 118 With --reference, change the group of each FILE to that of RFILE.\n\
 119 \n\
 120   -c, --changes          like verbose but report only when a change is made\n\
 121       --dereference      affect the referent of each symbolic link (this is\n\
 122                          the default), rather than the symbolic link itself\n\
 123 "), stdout);
 124       fputs (_("\
 125   -h, --no-dereference   affect each symbolic link instead of any referenced\n\
 126                          file (useful only on systems that can change the\n\
 127                          ownership of a symlink)\n\
 128 "), stdout);
 129       fputs (_("\
 130       --no-preserve-root  do not treat `/' specially (the default)\n\
 131       --preserve-root    fail to operate recursively on `/'\n\
 132 "), stdout);
 133       fputs (_("\
 134   -f, --silent, --quiet  suppress most error messages\n\
 135       --reference=RFILE  use RFILE's group rather than specifying a\n\
 136                          GROUP value\n\
 137   -R, --recursive        operate on files and directories recursively\n\
 138   -v, --verbose          output a diagnostic for every file processed\n\
 139 \n\
 140 "), stdout);
 141       fputs (_("\
 142 The following options modify how a hierarchy is traversed when the -R\n\
 143 option is also specified.  If more than one is specified, only the final\n\
 144 one takes effect.\n\
 145 \n\
 146   -H                     if a command line argument is a symbolic link\n\
 147                          to a directory, traverse it\n\
 148   -L                     traverse every symbolic link to a directory\n\
 149                          encountered\n\
 150   -P                     do not traverse any symbolic links (default)\n\
 151 \n\
 152 "), stdout);
 153       fputs (HELP_OPTION_DESCRIPTION, stdout);
 154       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 155       printf (_("\
 156 \n\
 157 Examples:\n\
 158   %s staff /u      Change the group of /u to \"staff\".\n\
 159   %s -hR staff /u  Change the group of /u and subfiles to \"staff\".\n\
 160 "),
 161               program_name, program_name);
 162       emit_bug_reporting_address ();
 163     }
 164   exit (status);
 165 }
 166
 167 int
 168 main (int argc, char **argv)
 169 {
 170   bool preserve_root = false;
 171   gid_t gid;
 172
 173   /* Bit flags that control how fts works.  */
 174   int bit_flags = FTS_PHYSICAL;
 175
 176   /* 1 if --dereference, 0 if --no-dereference, -1 if neither has been
 177      specified.  */
 178   int dereference = -1;
 179
 180   struct Chown_option chopt;
 181   bool ok;
 182   int optc;
 183
 184   initialize_main (&argc, &argv);
 185   program_name = argv[0];
 186   setlocale (LC_ALL, "");
 187   bindtextdomain (PACKAGE, LOCALEDIR);
 188   textdomain (PACKAGE);
 189
 190   atexit (close_stdout);
 191
 192   chopt_init (&chopt);
 193
 194   while ((optc = getopt_long (argc, argv, "HLPRcfhv", long_options, NULL))
 195          != -1)
 196     {
 197       switch (optc)
 198         {
 199         case 'H': /* Traverse command-line symlinks-to-directories.  */
 200           bit_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
 201           break;
 202
 203         case 'L': /* Traverse all symlinks-to-directories.  */
 204           bit_flags = FTS_LOGICAL;
 205           break;
 206
 207         case 'P': /* Traverse no symlinks-to-directories.  */
 208           bit_flags = FTS_PHYSICAL;
 209           break;
 210
 211         case 'h': /* --no-dereference: affect symlinks */
 212           dereference = 0;
 213           break;
 214
 215         case DEREFERENCE_OPTION: /* --dereference: affect the referent
 216                                     of each symlink */
 217           dereference = 1;
 218           break;
 219
 220         case NO_PRESERVE_ROOT:
 221           preserve_root = false;
 222           break;
 223
 224         case PRESERVE_ROOT:
 225           preserve_root = true;
 226           break;
 227
 228         case REFERENCE_FILE_OPTION:
 229           reference_file = optarg;
 230           break;
 231
 232         case 'R':
 233           chopt.recurse = true;
 234           break;
 235
 236         case 'c':
 237           chopt.verbosity = V_changes_only;
 238           break;
 239
 240         case 'f':
 241           chopt.force_silent = true;
 242           break;
 243
 244         case 'v':
 245           chopt.verbosity = V_high;
 246           break;
 247
 248         case_GETOPT_HELP_CHAR;
 249         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 250         default:
 251           usage (EXIT_FAILURE);
 252         }
 253     }
 254
 255   if (chopt.recurse)
 256     {
 257       if (bit_flags == FTS_PHYSICAL)
 258         {
 259           if (dereference == 1)
 260             error (EXIT_FAILURE, 0,
 261                    _("-R --dereference requires either -H or -L"));
 262           dereference = 0;
 263         }
 264     }
 265   else
 266     {
 267       bit_flags = FTS_PHYSICAL;
 268     }
 269   chopt.affect_symlink_referent = (dereference != 0);
 270
 271   if (argc - optind < (reference_file ? 1 : 2))
 272     {
 273       if (argc <= optind)
 274         error (0, 0, _("missing operand"));
 275       else
 276         error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
 277       usage (EXIT_FAILURE);
 278     }
 279
 280   if (reference_file)
 281     {
 282       struct stat ref_stats;
 283       if (stat (reference_file, &ref_stats))
 284         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 285                quote (reference_file));
 286
 287       gid = ref_stats.st_gid;
 288       chopt.group_name = gid_to_name (ref_stats.st_gid);
 289     }
 290   else
 291     {
 292       char *group_name = argv[optind++];
 293       chopt.group_name = (*group_name ? group_name : NULL);
 294       gid = parse_group (group_name);
 295     }
 296
 297   if (chopt.recurse & preserve_root)
 298     {
 299       static struct dev_ino dev_ino_buf;
 300       chopt.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 301       if (chopt.root_dev_ino == NULL)
 302         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 303                quote ("/"));
 304     }
 305
 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 }