src/chmod.c

   1 /* chmod -- change permission modes of files
   2    Copyright (C) 89, 90, 91, 1995-2002 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 (const char *dir, const struct mode_change *changes);
  57
  58 /* The name the program was run with. */
  59 char *program_name;
  60
  61 /* If nonzero, change the modes of directories recursively. */
  62 static int recurse;
  63
  64 /* If nonzero, force silence (no error messages). */
  65 static int force_silent;
  66
  67 /* Level of verbosity.  */
  68 static enum Verbosity verbosity = V_off;
  69
  70 /* The argument to the --reference option.  Use the owner and group IDs
  71    of this file.  This file must exist.  */
  72 static char *reference_file;
  73
  74 /* For long options that have no equivalent short option, use a
  75    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  76 enum
  77 {
  78   REFERENCE_FILE_OPTION = CHAR_MAX + 1
  79 };
  80
  81 static struct option const long_options[] =
  82 {
  83   {"recursive", no_argument, 0, 'R'},
  84   {"changes", no_argument, 0, 'c'},
  85   {"silent", no_argument, 0, 'f'},
  86   {"quiet", no_argument, 0, 'f'},
  87   {"reference", required_argument, 0, REFERENCE_FILE_OPTION},
  88   {"verbose", no_argument, 0, 'v'},
  89   {GETOPT_HELP_OPTION_DECL},
  90   {GETOPT_VERSION_OPTION_DECL},
  91   {0, 0, 0, 0}
  92 };
  93
  94 static int
  95 mode_changed (const char *file, mode_t old_mode)
  96 {
  97   struct stat new_stats;
  98
  99   if (stat (file, &new_stats))
 100     {
 101       if (force_silent == 0)
 102         error (0, errno, _("getting new attributes of %s"), quote (file));
 103       return 0;
 104     }
 105
 106   return old_mode != new_stats.st_mode;
 107 }
 108
 109 /* Tell the user how/if the MODE of FILE has been changed.
 110    CHANGED describes what (if anything) has happened. */
 111
 112 static void
 113 describe_change (const char *file, mode_t mode,
 114                  enum Change_status changed)
 115 {
 116   char perms[11];               /* "-rwxrwxrwx" ls-style modes. */
 117   const char *fmt;
 118
 119   mode_string (mode, perms);
 120   perms[10] = '\0';             /* `mode_string' does not null terminate. */
 121   switch (changed)
 122     {
 123     case CH_SUCCEEDED:
 124       fmt = _("mode of %s changed to %04lo (%s)\n");
 125       break;
 126     case CH_FAILED:
 127       fmt = _("failed to change mode of %s to %04lo (%s)\n");
 128       break;
 129     case CH_NO_CHANGE_REQUESTED:
 130       fmt = _("mode of %s retained as %04lo (%s)\n");
 131       break;
 132     default:
 133       abort ();
 134     }
 135   printf (fmt, quote (file),
 136           (unsigned long) (mode & CHMOD_MODE_BITS), &perms[1]);
 137 }
 138
 139 /* Change the mode of FILE according to the list of operations CHANGES.
 140    If DEREF_SYMLINK is nonzero and FILE is a symbolic link, change the
 141    mode of the referenced file.  If DEREF_SYMLINK is zero, ignore symbolic
 142    links.  Return 0 if successful, 1 if errors occurred. */
 143
 144 static int
 145 change_file_mode (const char *file, const struct mode_change *changes,
 146                   const int deref_symlink)
 147 {
 148   struct stat file_stats;
 149   mode_t newmode;
 150   int errors = 0;
 151   int fail;
 152   int saved_errno;
 153
 154   if (deref_symlink ? stat (file, &file_stats) : lstat (file, &file_stats))
 155     {
 156       if (force_silent == 0)
 157         error (0, errno, _("failed to get attributes of %s"), quote (file));
 158       return 1;
 159     }
 160
 161 #ifdef S_ISLNK
 162   if (S_ISLNK (file_stats.st_mode))
 163     return 0;
 164 #endif
 165
 166   newmode = mode_adjust (file_stats.st_mode, changes);
 167
 168   fail = chmod (file, newmode);
 169   saved_errno = errno;
 170
 171   if (verbosity == V_high
 172       || (verbosity == V_changes_only
 173           && !fail && mode_changed (file, file_stats.st_mode)))
 174     describe_change (file, newmode, (fail ? CH_FAILED : CH_SUCCEEDED));
 175
 176   if (fail)
 177     {
 178       if (force_silent == 0)
 179         error (0, saved_errno, _("changing permissions of %s"),
 180                quote (file));
 181       errors = 1;
 182     }
 183
 184   if (recurse && S_ISDIR (file_stats.st_mode))
 185     errors |= change_dir_mode (file, changes);
 186   return errors;
 187 }
 188
 189 /* Recursively change the modes of the files in directory DIR
 190    according to the list of operations CHANGES.
 191    Return 0 if successful, 1 if errors occurred. */
 192
 193 static int
 194 change_dir_mode (const char *dir, const struct mode_change *changes)
 195 {
 196   char *name_space, *namep;
 197   char *path;                   /* Full path of each entry to process. */
 198   unsigned dirlength;           /* Length of DIR and '\0'. */
 199   unsigned filelength;          /* Length of each pathname to process. */
 200   unsigned pathlength;          /* Bytes allocated for `path'. */
 201   int errors = 0;
 202
 203   name_space = savedir (dir);
 204   if (name_space == NULL)
 205     {
 206       if (force_silent == 0)
 207         error (0, errno, "%s", quote (dir));
 208       return 1;
 209     }
 210
 211   dirlength = strlen (dir) + 1; /* + 1 is for the trailing '/'. */
 212   pathlength = dirlength + 1;
 213   /* Give `path' a dummy value; it will be reallocated before first use. */
 214   path = xmalloc (pathlength);
 215   strcpy (path, dir);
 216   path[dirlength - 1] = '/';
 217
 218   for (namep = name_space; *namep; namep += filelength - dirlength)
 219     {
 220       filelength = dirlength + strlen (namep) + 1;
 221       if (filelength > pathlength)
 222         {
 223           pathlength = filelength * 2;
 224           path = xrealloc (path, pathlength);
 225         }
 226       strcpy (path + dirlength, namep);
 227       errors |= change_file_mode (path, changes, 0);
 228     }
 229   free (path);
 230   free (name_space);
 231   return errors;
 232 }
 233
 234 void
 235 usage (int status)
 236 {
 237   if (status != 0)
 238     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 239              program_name);
 240   else
 241     {
 242       printf (_("\
 243 Usage: %s [OPTION]... MODE[,MODE]... FILE...\n\
 244   or:  %s [OPTION]... OCTAL-MODE FILE...\n\
 245   or:  %s [OPTION]... --reference=RFILE FILE...\n\
 246 "),
 247               program_name, program_name, program_name);
 248       fputs (_("\
 249 Change the mode of each FILE to MODE.\n\
 250 \n\
 251   -c, --changes           like verbose but report only when a change is made\n\
 252   -f, --silent, --quiet   suppress most error messages\n\
 253   -v, --verbose           output a diagnostic for every file processed\n\
 254       --reference=RFILE   use RFILE's mode instead of MODE values\n\
 255   -R, --recursive         change files and directories recursively\n\
 256 "), stdout);
 257       fputs (HELP_OPTION_DESCRIPTION, stdout);
 258       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 259       fputs (_("\
 260 \n\
 261 Each MODE is one or more of the letters ugoa, one of the symbols +-= and\n\
 262 one or more of the letters rwxXstugo.\n\
 263 "), stdout);
 264       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 265     }
 266   exit (status);
 267 }
 268
 269 /* Parse the ASCII mode given on the command line into a linked list
 270    of `struct mode_change' and apply that to each file argument. */
 271
 272 int
 273 main (int argc, char **argv)
 274 {
 275   struct mode_change *changes;
 276   int errors = 0;
 277   int modeind = 0;              /* Index of the mode argument in `argv'. */
 278   int thisind;
 279   int c;
 280
 281   program_name = argv[0];
 282   setlocale (LC_ALL, "");
 283   bindtextdomain (PACKAGE, LOCALEDIR);
 284   textdomain (PACKAGE);
 285
 286   atexit (close_stdout);
 287
 288   recurse = force_silent = 0;
 289
 290   while (1)
 291     {
 292       thisind = optind ? optind : 1;
 293
 294       c = getopt_long (argc, argv, "RcfvrwxXstugoa,+-=", long_options, NULL);
 295       if (c == -1)
 296         break;
 297
 298       switch (c)
 299         {
 300         case 0:
 301           break;
 302         case 'r':
 303         case 'w':
 304         case 'x':
 305         case 'X':
 306         case 's':
 307         case 't':
 308         case 'u':
 309         case 'g':
 310         case 'o':
 311         case 'a':
 312         case ',':
 313         case '+':
 314         case '-':
 315         case '=':
 316           if (modeind != 0 && modeind != thisind)
 317             {
 318               static char char_string[2] = {0, 0};
 319               char_string[0] = c;
 320               error (EXIT_FAILURE, 0, _("invalid character %s in mode string %s"),
 321                      quote_n (0, char_string), quote_n (1, argv[thisind]));
 322             }
 323           modeind = thisind;
 324           break;
 325         case REFERENCE_FILE_OPTION:
 326           reference_file = optarg;
 327           break;
 328         case 'R':
 329           recurse = 1;
 330           break;
 331         case 'c':
 332           verbosity = V_changes_only;
 333           break;
 334         case 'f':
 335           force_silent = 1;
 336           break;
 337         case 'v':
 338           verbosity = V_high;
 339           break;
 340         case_GETOPT_HELP_CHAR;
 341         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 342         default:
 343           usage (EXIT_FAILURE);
 344         }
 345     }
 346
 347   if (modeind == 0 && reference_file == NULL)
 348     modeind = optind++;
 349
 350   if (optind >= argc)
 351     {
 352       error (0, 0, _("too few arguments"));
 353       usage (EXIT_FAILURE);
 354     }
 355
 356   changes = (reference_file ? mode_create_from_ref (reference_file)
 357              : mode_compile (argv[modeind], MODE_MASK_ALL));
 358
 359   if (changes == MODE_INVALID)
 360     error (EXIT_FAILURE, 0,
 361            _("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 (EXIT_FAILURE, 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 }