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 "lchown.h"
  32 #include "quote.h"
  33 #include "root-dev-ino.h"
  34 #include "xstrtol.h"
  35
  36 /* The official name of this program (e.g., no `g' prefix).  */
  37 #define PROGRAM_NAME "chgrp"
  38
  39 #define AUTHORS "David MacKenzie", "Jim Meyering"
  40
  41 #if ! HAVE_ENDGRENT
  42 # define endgrent() ((void) 0)
  43 #endif
  44
  45 /* The name the program was run with. */
  46 char *program_name;
  47
  48 /* The argument to the --reference option.  Use the group ID of this file.
  49    This file must exist.  */
  50 static char *reference_file;
  51
  52 /* For long options that have no equivalent short option, use a
  53    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  54 enum
  55 {
  56   DEREFERENCE_OPTION = CHAR_MAX + 1,
  57   NO_PRESERVE_ROOT,
  58   PRESERVE_ROOT,
  59   REFERENCE_FILE_OPTION
  60 };
  61
  62 static struct option const long_options[] =
  63 {
  64   {"recursive", no_argument, NULL, 'R'},
  65   {"changes", no_argument, NULL, 'c'},
  66   {"dereference", no_argument, NULL, DEREFERENCE_OPTION},
  67   {"no-dereference", no_argument, NULL, 'h'},
  68   {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
  69   {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
  70   {"quiet", no_argument, NULL, 'f'},
  71   {"silent", no_argument, NULL, 'f'},
  72   {"reference", required_argument, NULL, REFERENCE_FILE_OPTION},
  73   {"verbose", no_argument, NULL, 'v'},
  74   {GETOPT_HELP_OPTION_DECL},
  75   {GETOPT_VERSION_OPTION_DECL},
  76   {NULL, 0, NULL, 0}
  77 };
  78
  79 /* Return the group ID of NAME, or -1 if no name was specified.  */
  80
  81 static gid_t
  82 parse_group (const char *name)
  83 {
  84   gid_t gid = -1;
  85
  86   if (*name)
  87     {
  88       struct group *grp = getgrnam (name);
  89       if (grp)
  90         gid = grp->gr_gid;
  91       else
  92         {
  93           unsigned long int tmp;
  94           if (! (xstrtoul (name, NULL, 10, &tmp, "") == LONGINT_OK
  95                  && tmp <= GID_T_MAX))
  96             error (EXIT_FAILURE, 0, _("invalid group %s"), quote (name));
  97           gid = tmp;
  98         }
  99       endgrent ();              /* Save a file descriptor. */
 100     }
 101
 102   return gid;
 103 }
 104
 105 void
 106 usage (int status)
 107 {
 108   if (status != EXIT_SUCCESS)
 109     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 110              program_name);
 111   else
 112     {
 113       printf (_("\
 114 Usage: %s [OPTION]... GROUP FILE...\n\
 115   or:  %s [OPTION]... --reference=RFILE FILE...\n\
 116 "),
 117               program_name, program_name);
 118       fputs (_("\
 119 Change the group of each FILE to GROUP.\n\
 120 With --reference, change the group of each FILE to that of RFILE.\n\
 121 \n\
 122   -c, --changes          like verbose but report only when a change is made\n\
 123       --dereference      affect the referent of each symbolic link (this is\n\
 124                          the default), rather than the symbolic link itself\n\
 125 "), stdout);
 126       fputs (_("\
 127   -h, --no-dereference   affect each symbolic link instead of any referenced\n\
 128                          file (useful only on systems that can change the\n\
 129                          ownership of a symlink)\n\
 130 "), stdout);
 131       fputs (_("\
 132       --no-preserve-root  do not treat `/' specially (the default)\n\
 133       --preserve-root    fail to operate recursively on `/'\n\
 134 "), stdout);
 135       fputs (_("\
 136   -f, --silent, --quiet  suppress most error messages\n\
 137       --reference=RFILE  use RFILE's group rather than specifying a\n\
 138                          GROUP value\n\
 139   -R, --recursive        operate on files and directories recursively\n\
 140   -v, --verbose          output a diagnostic for every file processed\n\
 141 \n\
 142 "), stdout);
 143       fputs (_("\
 144 The following options modify how a hierarchy is traversed when the -R\n\
 145 option is also specified.  If more than one is specified, only the final\n\
 146 one takes effect.\n\
 147 \n\
 148   -H                     if a command line argument is a symbolic link\n\
 149                          to a directory, traverse it\n\
 150   -L                     traverse every symbolic link to a directory\n\
 151                          encountered\n\
 152   -P                     do not traverse any symbolic links (default)\n\
 153 \n\
 154 "), stdout);
 155       fputs (HELP_OPTION_DESCRIPTION, stdout);
 156       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 157       printf (_("\
 158 \n\
 159 Examples:\n\
 160   %s staff /u      Change the group of /u to \"staff\".\n\
 161   %s -hR staff /u  Change the group of /u and subfiles to \"staff\".\n\
 162 "),
 163               program_name, program_name);
 164       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 165     }
 166   exit (status);
 167 }
 168
 169 int
 170 main (int argc, char **argv)
 171 {
 172   bool preserve_root = false;
 173   gid_t gid;
 174
 175   /* Bit flags that control how fts works.  */
 176   int bit_flags = FTS_PHYSICAL;
 177
 178   /* 1 if --dereference, 0 if --no-dereference, -1 if neither has been
 179      specified.  */
 180   int dereference = -1;
 181
 182   struct Chown_option chopt;
 183   bool ok;
 184   int optc;
 185
 186   initialize_main (&argc, &argv);
 187   program_name = argv[0];
 188   setlocale (LC_ALL, "");
 189   bindtextdomain (PACKAGE, LOCALEDIR);
 190   textdomain (PACKAGE);
 191
 192   atexit (close_stdout);
 193
 194   chopt_init (&chopt);
 195
 196   while ((optc = getopt_long (argc, argv, "HLPRcfhv", long_options, NULL))
 197          != -1)
 198     {
 199       switch (optc)
 200         {
 201         case 'H': /* Traverse command-line symlinks-to-directories.  */
 202           bit_flags = FTS_COMFOLLOW | FTS_PHYSICAL;
 203           break;
 204
 205         case 'L': /* Traverse all symlinks-to-directories.  */
 206           bit_flags = FTS_LOGICAL;
 207           break;
 208
 209         case 'P': /* Traverse no symlinks-to-directories.  */
 210           bit_flags = FTS_PHYSICAL;
 211           break;
 212
 213         case 'h': /* --no-dereference: affect symlinks */
 214           dereference = 0;
 215           break;
 216
 217         case DEREFERENCE_OPTION: /* --dereference: affect the referent
 218                                     of each symlink */
 219           dereference = 1;
 220           break;
 221
 222         case NO_PRESERVE_ROOT:
 223           preserve_root = false;
 224           break;
 225
 226         case PRESERVE_ROOT:
 227           preserve_root = true;
 228           break;
 229
 230         case REFERENCE_FILE_OPTION:
 231           reference_file = optarg;
 232           break;
 233
 234         case 'R':
 235           chopt.recurse = true;
 236           break;
 237
 238         case 'c':
 239           chopt.verbosity = V_changes_only;
 240           break;
 241
 242         case 'f':
 243           chopt.force_silent = true;
 244           break;
 245
 246         case 'v':
 247           chopt.verbosity = V_high;
 248           break;
 249
 250         case_GETOPT_HELP_CHAR;
 251         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 252         default:
 253           usage (EXIT_FAILURE);
 254         }
 255     }
 256
 257   if (chopt.recurse)
 258     {
 259       if (bit_flags == FTS_PHYSICAL)
 260         {
 261           if (dereference == 1)
 262             error (EXIT_FAILURE, 0,
 263                    _("-R --dereference requires either -H or -L"));
 264           chopt.affect_symlink_referent = false;
 265         }
 266       else
 267         {
 268           if (dereference == 0)
 269             error (EXIT_FAILURE, 0, _("-R -h requires -P"));
 270           chopt.affect_symlink_referent = true;
 271         }
 272     }
 273   else
 274     {
 275       bit_flags = FTS_PHYSICAL;
 276       chopt.affect_symlink_referent = (dereference != 0);
 277     }
 278
 279   if (argc - optind < (reference_file ? 1 : 2))
 280     {
 281       if (argc <= optind)
 282         error (0, 0, _("missing operand"));
 283       else
 284         error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
 285       usage (EXIT_FAILURE);
 286     }
 287
 288   if (reference_file)
 289     {
 290       struct stat ref_stats;
 291       if (stat (reference_file, &ref_stats))
 292         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 293                quote (reference_file));
 294
 295       gid = ref_stats.st_gid;
 296       chopt.group_name = gid_to_name (ref_stats.st_gid);
 297     }
 298   else
 299     {
 300       char *group_name = argv[optind++];
 301       chopt.group_name = (*group_name ? group_name : NULL);
 302       gid = parse_group (group_name);
 303     }
 304
 305   if (chopt.recurse & preserve_root)
 306     {
 307       static struct dev_ino dev_ino_buf;
 308       chopt.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 309       if (chopt.root_dev_ino == NULL)
 310         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 311                quote ("/"));
 312     }
 313
 314   ok = chown_files (argv + optind, bit_flags,
 315                     (uid_t) -1, gid,
 316                     (uid_t) -1, (gid_t) -1, &chopt);
 317
 318   chopt_free (&chopt);
 319
 320   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 321 }