src/chgrp.c

   1 /* chgrp -- change group ownership of files
   2    Copyright (C) 1989-2015 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"),
  93                    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     emit_try_help ();
 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 "), stdout);
 119       fputs (_("\
 120   -c, --changes          like verbose but report only when a change is made\n\
 121   -f, --silent, --quiet  suppress most error messages\n\
 122   -v, --verbose          output a diagnostic for every file processed\n\
 123 "), stdout);
 124       fputs (_("\
 125       --dereference      affect the referent of each symbolic link (this is\n\
 126                          the default), rather than the symbolic link itself\n\
 127   -h, --no-dereference   affect symbolic links instead of any referenced file\n\
 128 "), stdout);
 129       fputs (_("\
 130                          (useful only on systems that can change the\n\
 131                          ownership of a symlink)\n\
 132 "), stdout);
 133       fputs (_("\
 134       --no-preserve-root  do not treat '/' specially (the default)\n\
 135       --preserve-root    fail to operate recursively on '/'\n\
 136 "), stdout);
 137       fputs (_("\
 138       --reference=RFILE  use RFILE's group rather than specifying a\n\
 139                          GROUP value\n\
 140 "), stdout);
 141       fputs (_("\
 142   -R, --recursive        operate on files and directories recursively\n\
 143 "), stdout);
 144       fputs (_("\
 145 \n\
 146 The following options modify how a hierarchy is traversed when the -R\n\
 147 option is also specified.  If more than one is specified, only the final\n\
 148 one takes effect.\n\
 149 \n\
 150   -H                     if a command line argument is a symbolic link\n\
 151                          to a directory, traverse it\n\
 152   -L                     traverse every symbolic link to a directory\n\
 153                          encountered\n\
 154   -P                     do not traverse any symbolic links (default)\n\
 155 \n\
 156 "), stdout);
 157       fputs (HELP_OPTION_DESCRIPTION, stdout);
 158       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 159       printf (_("\
 160 \n\
 161 Examples:\n\
 162   %s staff /u      Change the group of /u to \"staff\".\n\
 163   %s -hR staff /u  Change the group of /u and subfiles to \"staff\".\n\
 164 "),
 165               program_name, program_name);
 166       emit_ancillary_info (PROGRAM_NAME);
 167     }
 168   exit (status);
 169 }
 170
 171 int
 172 main (int argc, char **argv)
 173 {
 174   bool preserve_root = false;
 175   gid_t gid;
 176
 177   /* Bit flags that control how fts works.  */
 178   int bit_flags = FTS_PHYSICAL;
 179
 180   /* 1 if --dereference, 0 if --no-dereference, -1 if neither has been
 181      specified.  */
 182   int dereference = -1;
 183
 184   struct Chown_option chopt;
 185   bool ok;
 186   int optc;
 187
 188   initialize_main (&argc, &argv);
 189   set_program_name (argv[0]);
 190   setlocale (LC_ALL, "");
 191   bindtextdomain (PACKAGE, LOCALEDIR);
 192   textdomain (PACKAGE);
 193
 194   atexit (close_stdout);
 195
 196   chopt_init (&chopt);
 197
 198   while ((optc = getopt_long (argc, argv, "HLPRcfhv", long_options, NULL))
 199          != -1)
 200     {
 201       switch (optc)
 202         {
 203         case 'H': /* Traverse command-line symlinks-to-directories.  */
 204           bit_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
 205           break;
 206
 207         case 'L': /* Traverse all symlinks-to-directories.  */
 208           bit_flags = FTS_LOGICAL;
 209           break;
 210
 211         case 'P': /* Traverse no symlinks-to-directories.  */
 212           bit_flags = FTS_PHYSICAL;
 213           break;
 214
 215         case 'h': /* --no-dereference: affect symlinks */
 216           dereference = 0;
 217           break;
 218
 219         case DEREFERENCE_OPTION: /* --dereference: affect the referent
 220                                     of each symlink */
 221           dereference = 1;
 222           break;
 223
 224         case NO_PRESERVE_ROOT:
 225           preserve_root = false;
 226           break;
 227
 228         case PRESERVE_ROOT:
 229           preserve_root = true;
 230           break;
 231
 232         case REFERENCE_FILE_OPTION:
 233           reference_file = optarg;
 234           break;
 235
 236         case 'R':
 237           chopt.recurse = true;
 238           break;
 239
 240         case 'c':
 241           chopt.verbosity = V_changes_only;
 242           break;
 243
 244         case 'f':
 245           chopt.force_silent = true;
 246           break;
 247
 248         case 'v':
 249           chopt.verbosity = V_high;
 250           break;
 251
 252         case_GETOPT_HELP_CHAR;
 253         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 254         default:
 255           usage (EXIT_FAILURE);
 256         }
 257     }
 258
 259   if (chopt.recurse)
 260     {
 261       if (bit_flags == FTS_PHYSICAL)
 262         {
 263           if (dereference == 1)
 264             error (EXIT_FAILURE, 0,
 265                    _("-R --dereference requires either -H or -L"));
 266           dereference = 0;
 267         }
 268     }
 269   else
 270     {
 271       bit_flags = FTS_PHYSICAL;
 272     }
 273   chopt.affect_symlink_referent = (dereference != 0);
 274
 275   if (argc - optind < (reference_file ? 1 : 2))
 276     {
 277       if (argc <= optind)
 278         error (0, 0, _("missing operand"));
 279       else
 280         error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
 281       usage (EXIT_FAILURE);
 282     }
 283
 284   if (reference_file)
 285     {
 286       struct stat ref_stats;
 287       if (stat (reference_file, &ref_stats))
 288         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 289                quoteaf (reference_file));
 290
 291       gid = ref_stats.st_gid;
 292       chopt.group_name = gid_to_name (ref_stats.st_gid);
 293     }
 294   else
 295     {
 296       char *group_name = argv[optind++];
 297       chopt.group_name = (*group_name ? group_name : NULL);
 298       gid = parse_group (group_name);
 299     }
 300
 301   if (chopt.recurse && preserve_root)
 302     {
 303       static struct dev_ino dev_ino_buf;
 304       chopt.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 305       if (chopt.root_dev_ino == NULL)
 306         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 307                quoteaf ("/"));
 308     }
 309
 310   bit_flags |= FTS_DEFER_STAT;
 311   ok = chown_files (argv + optind, bit_flags,
 312                     (uid_t) -1, gid,
 313                     (uid_t) -1, (gid_t) -1, &chopt);
 314
 315   chopt_free (&chopt);
 316
 317   return ok ? EXIT_SUCCESS : EXIT_FAILURE;
 318 }