src/chmod.c

   1 /* chmod -- change permission modes of files
   2    Copyright (C) 89, 90, 91, 1995-2001 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Written by David MacKenzie <djm@gnu.ai.mit.edu> */
  19
  20 #include <config.h>
  21 #include <stdio.h>
  22 #include <getopt.h>
  23 #include <sys/types.h>
  24
  25 #include "system.h"
  26 #include "error.h"
  27 #include "filemode.h"
  28 #include "modechange.h"
  29 #include "quote.h"
  30 #include "savedir.h"
  31
  32 /* The official name of this program (e.g., no `g' prefix).  */
  33 #define PROGRAM_NAME "chmod"
  34
  35 #define AUTHORS "David MacKenzie"
  36
  37 enum Change_status
  38 {
  39   CH_SUCCEEDED,
  40   CH_FAILED,
  41   CH_NO_CHANGE_REQUESTED
  42 };
  43
  44 enum Verbosity
  45 {
  46   /* Print a message for each file that is processed.  */
  47   V_high,
  48
  49   /* Print a message for each file whose attributes we change.  */
  50   V_changes_only,
  51
  52   /* Do not be verbose.  This is the default. */
  53   V_off
  54 };
  55
  56 static int change_dir_mode PARAMS ((const char *dir,
  57                                     const struct mode_change *changes));
  58
  59 /* The name the program was run with. */
  60 char *program_name;
  61
  62 /* If nonzero, change the modes of directories recursively. */
  63 static int recurse;
  64
  65 /* If nonzero, force silence (no error messages). */
  66 static int force_silent;
  67
  68 /* Level of verbosity.  */
  69 static enum Verbosity verbosity = V_off;
  70
  71 /* The argument to the --reference option.  Use the owner and group IDs
  72    of this file.  This file must exist.  */
  73 static char *reference_file;
  74
  75 /* For long options that have no equivalent short option, use a
  76    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  77 enum
  78 {
  79   REFERENCE_FILE_OPTION = CHAR_MAX + 1
  80 };
  81
  82 static struct option const long_options[] =
  83 {
  84   {"recursive", no_argument, 0, 'R'},
  85   {"changes", no_argument, 0, 'c'},
  86   {"silent", no_argument, 0, 'f'},
  87   {"quiet", no_argument, 0, 'f'},
  88   {"reference", required_argument, 0, REFERENCE_FILE_OPTION},
  89   {"verbose", no_argument, 0, 'v'},
  90   {GETOPT_HELP_OPTION_DECL},
  91   {GETOPT_VERSION_OPTION_DECL},
  92   {0, 0, 0, 0}
  93 };
  94
  95 static int
  96 mode_changed (const char *file, mode_t old_mode)
  97 {
  98   struct stat new_stats;
  99
 100   if (stat (file, &new_stats))
 101     {
 102       if (force_silent == 0)
 103         error (0, errno, _("getting new attributes of %s"), quote (file));
 104       return 0;
 105     }
 106
 107   return old_mode != new_stats.st_mode;
 108 }
 109
 110 /* Tell the user how/if the MODE of FILE has been changed.
 111    CHANGED describes what (if anything) has happened. */
 112
 113 static void
 114 describe_change (const char *file, mode_t mode,
 115                  enum Change_status changed)
 116 {
 117   char perms[11];               /* "-rwxrwxrwx" ls-style modes. */
 118   const char *fmt;
 119
 120   mode_string (mode, perms);
 121   perms[10] = '\0';             /* `mode_string' does not null terminate. */
 122   switch (changed)
 123     {
 124     case CH_SUCCEEDED:
 125       fmt = _("mode of %s changed to %04lo (%s)\n");
 126       break;
 127     case CH_FAILED:
 128       fmt = _("failed to change mode of %s to %04lo (%s)\n");
 129       break;
 130     case CH_NO_CHANGE_REQUESTED:
 131       fmt = _("mode of %s retained as %04lo (%s)\n");
 132       break;
 133     default:
 134       abort ();
 135     }
 136   printf (fmt, quote (file),
 137           (unsigned long) (mode & CHMOD_MODE_BITS), &perms[1]);
 138 }
 139
 140 /* Change the mode of FILE according to the list of operations CHANGES.
 141    If DEREF_SYMLINK is nonzero and FILE is a symbolic link, change the
 142    mode of the referenced file.  If DEREF_SYMLINK is zero, ignore symbolic
 143    links.  Return 0 if successful, 1 if errors occurred. */
 144
 145 static int
 146 change_file_mode (const char *file, const struct mode_change *changes,
 147                   const int deref_symlink)
 148 {
 149   struct stat file_stats;
 150   mode_t newmode;
 151   int errors = 0;
 152   int fail;
 153   int saved_errno;
 154
 155   if (deref_symlink ? stat (file, &file_stats) : lstat (file, &file_stats))
 156     {
 157       if (force_silent == 0)
 158         error (0, errno, _("failed to get attributes of %s"), quote (file));
 159       return 1;
 160     }
 161
 162 #ifdef S_ISLNK
 163   if (S_ISLNK (file_stats.st_mode))
 164     return 0;
 165 #endif
 166
 167   newmode = mode_adjust (file_stats.st_mode, changes);
 168
 169   fail = chmod (file, newmode);
 170   saved_errno = errno;
 171
 172   if (verbosity == V_high
 173       || (verbosity == V_changes_only
 174           && !fail && mode_changed (file, file_stats.st_mode)))
 175     describe_change (file, newmode, (fail ? CH_FAILED : CH_SUCCEEDED));
 176
 177   if (fail)
 178     {
 179       if (force_silent == 0)
 180         error (0, saved_errno, _("changing permissions of %s"),
 181                quote (file));
 182       errors = 1;
 183     }
 184
 185   if (recurse && S_ISDIR (file_stats.st_mode))
 186     errors |= change_dir_mode (file, changes);
 187   return errors;
 188 }
 189
 190 /* Recursively change the modes of the files in directory DIR
 191    according to the list of operations CHANGES.
 192    Return 0 if successful, 1 if errors occurred. */
 193
 194 static int
 195 change_dir_mode (const char *dir, const struct mode_change *changes)
 196 {
 197   char *name_space, *namep;
 198   char *path;                   /* Full path of each entry to process. */
 199   unsigned dirlength;           /* Length of DIR and '\0'. */
 200   unsigned filelength;          /* Length of each pathname to process. */
 201   unsigned pathlength;          /* Bytes allocated for `path'. */
 202   int errors = 0;
 203
 204   name_space = savedir (dir);
 205   if (name_space == NULL)
 206     {
 207       if (force_silent == 0)
 208         error (0, errno, "%s", quote (dir));
 209       return 1;
 210     }
 211
 212   dirlength = strlen (dir) + 1; /* + 1 is for the trailing '/'. */
 213   pathlength = dirlength + 1;
 214   /* Give `path' a dummy value; it will be reallocated before first use. */
 215   path = xmalloc (pathlength);
 216   strcpy (path, dir);
 217   path[dirlength - 1] = '/';
 218
 219   for (namep = name_space; *namep; namep += filelength - dirlength)
 220     {
 221       filelength = dirlength + strlen (namep) + 1;
 222       if (filelength > pathlength)
 223         {
 224           pathlength = filelength * 2;
 225           path = xrealloc (path, pathlength);
 226         }
 227       strcpy (path + dirlength, namep);
 228       errors |= change_file_mode (path, changes, 0);
 229     }
 230   free (path);
 231   free (name_space);
 232   return errors;
 233 }
 234
 235 void
 236 usage (int status)
 237 {
 238   if (status != 0)
 239     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 240              program_name);
 241   else
 242     {
 243       printf (_("\
 244 Usage: %s [OPTION]... MODE[,MODE]... FILE...\n\
 245   or:  %s [OPTION]... OCTAL-MODE FILE...\n\
 246   or:  %s [OPTION]... --reference=RFILE FILE...\n\
 247 "),
 248               program_name, program_name, program_name);
 249       fputs (_("\
 250 Change the mode of each FILE to MODE.\n\
 251 \n\
 252   -c, --changes           like verbose but report only when a change is made\n\
 253   -f, --silent, --quiet   suppress most error messages\n\
 254   -v, --verbose           output a diagnostic for every file processed\n\
 255       --reference=RFILE   use RFILE's mode instead of MODE values\n\
 256   -R, --recursive         change files and directories recursively\n\
 257 "), stdout);
 258       fputs (HELP_OPTION_DESCRIPTION, stdout);
 259       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 260       fputs (_("\
 261 \n\
 262 Each MODE is one or more of the letters ugoa, one of the symbols +-= and\n\
 263 one or more of the letters rwxXstugo.\n\
 264 "), stdout);
 265       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 266     }
 267   exit (status);
 268 }
 269
 270 /* Parse the ASCII mode given on the command line into a linked list
 271    of `struct mode_change' and apply that to each file argument. */
 272
 273 int
 274 main (int argc, char **argv)
 275 {
 276   struct mode_change *changes;
 277   int errors = 0;
 278   int modeind = 0;              /* Index of the mode argument in `argv'. */
 279   int thisind;
 280   int c;
 281
 282   program_name = argv[0];
 283   setlocale (LC_ALL, "");
 284   bindtextdomain (PACKAGE, LOCALEDIR);
 285   textdomain (PACKAGE);
 286
 287   atexit (close_stdout);
 288
 289   recurse = force_silent = 0;
 290
 291   while (1)
 292     {
 293       thisind = optind ? optind : 1;
 294
 295       c = getopt_long (argc, argv, "RcfvrwxXstugoa,+-=", long_options, NULL);
 296       if (c == -1)
 297         break;
 298
 299       switch (c)
 300         {
 301         case 0:
 302           break;
 303         case 'r':
 304         case 'w':
 305         case 'x':
 306         case 'X':
 307         case 's':
 308         case 't':
 309         case 'u':
 310         case 'g':
 311         case 'o':
 312         case 'a':
 313         case ',':
 314         case '+':
 315         case '-':
 316         case '=':
 317           if (modeind != 0 && modeind != thisind)
 318             {
 319               static char char_string[2] = {0, 0};
 320               char_string[0] = c;
 321               error (1, 0, _("invalid character %s in mode string %s"),
 322                      quote_n (0, char_string), quote_n (1, argv[thisind]));
 323             }
 324           modeind = thisind;
 325           break;
 326         case REFERENCE_FILE_OPTION:
 327           reference_file = optarg;
 328           break;
 329         case 'R':
 330           recurse = 1;
 331           break;
 332         case 'c':
 333           verbosity = V_changes_only;
 334           break;
 335         case 'f':
 336           force_silent = 1;
 337           break;
 338         case 'v':
 339           verbosity = V_high;
 340           break;
 341         case_GETOPT_HELP_CHAR;
 342         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 343         default:
 344           usage (1);
 345         }
 346     }
 347
 348   if (modeind == 0 && reference_file == NULL)
 349     modeind = optind++;
 350
 351   if (optind >= argc)
 352     {
 353       error (0, 0, _("too few arguments"));
 354       usage (1);
 355     }
 356
 357   changes = (reference_file ? mode_create_from_ref (reference_file)
 358              : mode_compile (argv[modeind], MODE_MASK_ALL));
 359
 360   if (changes == MODE_INVALID)
 361     error (1, 0, _("invalid mode string: %s"), quote (argv[modeind]));
 362   else if (changes == MODE_MEMORY_EXHAUSTED)
 363     xalloc_die ();
 364   else if (changes == MODE_BAD_REFERENCE)
 365     error (1, errno, _("failed to get attributes of %s"),
 366            quote (reference_file));
 367
 368   for (; optind < argc; ++optind)
 369     errors |= change_file_mode (argv[optind], changes, 1);
 370
 371   exit (errors);
 372 }