src/chmod.c

   1 /* chmod -- change permission modes of files
   2    Copyright (C) 89, 90, 91, 1995-1999 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 "savedir.h"
  30
  31 /* The official name of this program (e.g., no `g' prefix).  */
  32 #define PROGRAM_NAME "chmod"
  33
  34 #define AUTHORS "David MacKenzie"
  35
  36 enum Change_status
  37 {
  38   CH_SUCCEEDED,
  39   CH_FAILED,
  40   CH_NO_CHANGE_REQUESTED
  41 };
  42
  43 enum Verbosity
  44 {
  45   /* Print a message for each file that is processed.  */
  46   V_high,
  47
  48   /* Print a message for each file whose attributes we change.  */
  49   V_changes_only,
  50
  51   /* Do not be verbose.  This is the default. */
  52   V_off
  53 };
  54
  55 void strip_trailing_slashes ();
  56
  57 static int change_dir_mode PARAMS ((const char *dir,
  58                                     const struct mode_change *changes,
  59                                     const struct stat *statp));
  60
  61 /* The name the program was run with. */
  62 char *program_name;
  63
  64 /* If nonzero, change the modes of directories recursively. */
  65 static int recurse;
  66
  67 /* If nonzero, force silence (no error messages). */
  68 static int force_silent;
  69
  70 /* Level of verbosity.  */
  71 static enum Verbosity verbosity = V_off;
  72
  73 /* The argument to the --reference option.  Use the owner and group IDs
  74    of this file.  This file must exist.  */
  75 static char *reference_file;
  76
  77 static struct option const long_options[] =
  78 {
  79   {"recursive", no_argument, 0, 'R'},
  80   {"changes", no_argument, 0, 'c'},
  81   {"silent", no_argument, 0, 'f'},
  82   {"quiet", no_argument, 0, 'f'},
  83   {"reference", required_argument, 0, CHAR_MAX + 1},
  84   {"verbose", no_argument, 0, 'v'},
  85   {GETOPT_HELP_OPTION_DECL},
  86   {GETOPT_VERSION_OPTION_DECL},
  87   {0, 0, 0, 0}
  88 };
  89
  90 /* Tell the user how/if the MODE of FILE has been changed.
  91    CHANGED describes what (if anything) has happened. */
  92
  93 static void
  94 describe_change (const char *file, mode_t mode,
  95                  enum Change_status changed)
  96 {
  97   char perms[11];               /* "-rwxrwxrwx" ls-style modes. */
  98   const char *fmt;
  99
 100   mode_string (mode, perms);
 101   perms[10] = '\0';             /* `mode_string' does not null terminate. */
 102   switch (changed)
 103     {
 104     case CH_SUCCEEDED:
 105       fmt = _("mode of %s changed to %04lo (%s)\n");
 106       break;
 107     case CH_FAILED:
 108       fmt = _("failed to change mode of %s to %04lo (%s)\n");
 109       break;
 110     case CH_NO_CHANGE_REQUESTED:
 111       fmt = _("mode of %s retained as %04lo (%s)\n");
 112       break;
 113     default:
 114       abort ();
 115     }
 116   printf (fmt, file, (unsigned long) (mode & CHMOD_MODE_BITS), &perms[1]);
 117 }
 118
 119 /* Change the mode of FILE according to the list of operations CHANGES.
 120    If DEREF_SYMLINK is nonzero and FILE is a symbolic link, change the
 121    mode of the referenced file.  If DEREF_SYMLINK is zero, ignore symbolic
 122    links.  Return 0 if successful, 1 if errors occurred. */
 123
 124 static int
 125 change_file_mode (const char *file, const struct mode_change *changes,
 126                   const int deref_symlink)
 127 {
 128   struct stat file_stats;
 129   mode_t newmode;
 130   int errors = 0;
 131
 132   if (lstat (file, &file_stats))
 133     {
 134       if (force_silent == 0)
 135         error (0, errno, "%s", file);
 136       return 1;
 137     }
 138 #ifdef S_ISLNK
 139   if (S_ISLNK (file_stats.st_mode))
 140     {
 141       if (! deref_symlink)
 142         return 0;
 143       else
 144         if (stat (file, &file_stats))
 145           {
 146             if (force_silent == 0)
 147               error (0, errno, "%s", file);
 148             return 1;
 149           }
 150     }
 151 #endif
 152
 153   newmode = mode_adjust (file_stats.st_mode, changes);
 154
 155   if (newmode != (file_stats.st_mode & CHMOD_MODE_BITS))
 156     {
 157       int fail = chmod (file, newmode);
 158
 159       if (verbosity == V_high || (verbosity == V_changes_only && !fail))
 160         describe_change (file, newmode, (fail ? CH_FAILED : CH_SUCCEEDED));
 161
 162       if (fail)
 163         {
 164           if (force_silent == 0)
 165             error (0, errno, "%s", file);
 166           errors = 1;
 167         }
 168     }
 169   else if (verbosity == V_high)
 170     describe_change (file, newmode, CH_NO_CHANGE_REQUESTED);
 171
 172   if (recurse && S_ISDIR (file_stats.st_mode))
 173     errors |= change_dir_mode (file, changes, &file_stats);
 174   return errors;
 175 }
 176
 177 /* Recursively change the modes of the files in directory DIR
 178    according to the list of operations CHANGES.
 179    STATP points to the results of lstat on DIR.
 180    Return 0 if successful, 1 if errors occurred. */
 181
 182 static int
 183 change_dir_mode (const char *dir, const struct mode_change *changes,
 184                  const struct stat *statp)
 185 {
 186   char *name_space, *namep;
 187   char *path;                   /* Full path of each entry to process. */
 188   unsigned dirlength;           /* Length of DIR and '\0'. */
 189   unsigned filelength;          /* Length of each pathname to process. */
 190   unsigned pathlength;          /* Bytes allocated for `path'. */
 191   int errors = 0;
 192
 193   errno = 0;
 194   name_space = savedir (dir, (unsigned int) statp->st_size);
 195   if (name_space == NULL)
 196     {
 197       if (errno)
 198         {
 199           if (force_silent == 0)
 200             error (0, errno, "%s", dir);
 201           return 1;
 202         }
 203       else
 204         error (1, 0, _("virtual memory exhausted"));
 205     }
 206
 207   dirlength = strlen (dir) + 1; /* + 1 is for the trailing '/'. */
 208   pathlength = dirlength + 1;
 209   /* Give `path' a dummy value; it will be reallocated before first use. */
 210   path = xmalloc (pathlength);
 211   strcpy (path, dir);
 212   path[dirlength - 1] = '/';
 213
 214   for (namep = name_space; *namep; namep += filelength - dirlength)
 215     {
 216       filelength = dirlength + strlen (namep) + 1;
 217       if (filelength > pathlength)
 218         {
 219           pathlength = filelength * 2;
 220           path = xrealloc (path, pathlength);
 221         }
 222       strcpy (path + dirlength, namep);
 223       errors |= change_file_mode (path, changes, 0);
 224     }
 225   free (path);
 226   free (name_space);
 227   return errors;
 228 }
 229
 230 void
 231 usage (int status)
 232 {
 233   if (status != 0)
 234     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 235              program_name);
 236   else
 237     {
 238       printf (_("\
 239 Usage: %s [OPTION]... MODE[,MODE]... FILE...\n\
 240   or:  %s [OPTION]... OCTAL-MODE FILE...\n\
 241   or:  %s [OPTION]... --reference=RFILE FILE...\n\
 242 "),
 243               program_name, program_name, program_name);
 244       printf (_("\
 245 Change the mode of each FILE to MODE.\n\
 246 \n\
 247   -c, --changes           like verbose but report only when a change is made\n\
 248   -f, --silent, --quiet   suppress most error messages\n\
 249   -v, --verbose           output a diagnostic for every file processed\n\
 250       --reference=RFILE   use RFILE's mode instead of MODE values\n\
 251   -R, --recursive         change files and directories recursively\n\
 252       --help              display this help and exit\n\
 253       --version           output version information and exit\n\
 254 \n\
 255 Each MODE is one or more of the letters ugoa, one of the symbols +-= and\n\
 256 one or more of the letters rwxXstugo.\n\
 257 "));
 258       puts (_("\nReport bugs to <bug-fileutils@gnu.org>."));
 259       close_stdout ();
 260     }
 261   exit (status);
 262 }
 263
 264 /* Parse the ASCII mode given on the command line into a linked list
 265    of `struct mode_change' and apply that to each file argument. */
 266
 267 int
 268 main (int argc, char **argv)
 269 {
 270   struct mode_change *changes;
 271   int errors = 0;
 272   int modeind = 0;              /* Index of the mode argument in `argv'. */
 273   int thisind;
 274   int c;
 275
 276   program_name = argv[0];
 277   setlocale (LC_ALL, "");
 278   bindtextdomain (PACKAGE, LOCALEDIR);
 279   textdomain (PACKAGE);
 280
 281   recurse = force_silent = 0;
 282
 283   while (1)
 284     {
 285       thisind = optind ? optind : 1;
 286
 287       c = getopt_long (argc, argv, "RcfvrwxXstugoa,+-=", long_options, NULL);
 288       if (c == -1)
 289         break;
 290
 291       switch (c)
 292         {
 293         case 0:
 294           break;
 295         case 'r':
 296         case 'w':
 297         case 'x':
 298         case 'X':
 299         case 's':
 300         case 't':
 301         case 'u':
 302         case 'g':
 303         case 'o':
 304         case 'a':
 305         case ',':
 306         case '+':
 307         case '-':
 308         case '=':
 309           if (modeind != 0 && modeind != thisind)
 310             error (1, 0, _("invalid mode"));
 311           modeind = thisind;
 312           break;
 313         case CHAR_MAX + 1:
 314           reference_file = optarg;
 315           break;
 316         case 'R':
 317           recurse = 1;
 318           break;
 319         case 'c':
 320           verbosity = V_changes_only;
 321           break;
 322         case 'f':
 323           force_silent = 1;
 324           break;
 325         case 'v':
 326           verbosity = V_high;
 327           break;
 328         case_GETOPT_HELP_CHAR;
 329         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 330         default:
 331           usage (1);
 332         }
 333     }
 334
 335   if (modeind == 0 && reference_file == NULL)
 336     modeind = optind++;
 337
 338   if (optind >= argc)
 339     {
 340       error (0, 0, _("too few arguments"));
 341       usage (1);
 342     }
 343
 344   changes = (reference_file ? mode_create_from_ref (reference_file)
 345              : mode_compile (argv[modeind], MODE_MASK_ALL));
 346
 347   if (changes == MODE_INVALID)
 348     error (1, 0, _("invalid mode"));
 349   else if (changes == MODE_MEMORY_EXHAUSTED)
 350     error (1, 0, _("virtual memory exhausted"));
 351   else if (changes == MODE_BAD_REFERENCE)
 352     error (1, errno, "%s", reference_file);
 353
 354   for (; optind < argc; ++optind)
 355     {
 356       strip_trailing_slashes (argv[optind]);
 357       errors |= change_file_mode (argv[optind], changes, 1);
 358     }
 359
 360   if (verbosity != V_off)
 361     close_stdout ();
 362   exit (errors);
 363 }