src/chmod.c

   1 /* chmod -- change permission modes of files
   2    Copyright (C) 1989, 1990, 1991, 1995 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
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  17
  18 /* Options:
  19    -R   Recursively change modes of directory contents.
  20    -c   Verbosely describe only files whose modes actually change.
  21    -f   Do not print error messages about files.
  22    -v   Verbosely describe changed modes.
  23
  24    David MacKenzie <djm@gnu.ai.mit.edu> */
  25
  26 #include <config.h>
  27 #include <stdio.h>
  28 #include <getopt.h>
  29 #include <sys/types.h>
  30
  31 #include "modechange.h"
  32 #include "system.h"
  33 #include "version.h"
  34 #include "error.h"
  35
  36 void mode_string ();
  37 char *savedir ();
  38 void strip_trailing_slashes ();
  39 char *xmalloc ();
  40 char *xrealloc ();
  41
  42 static int change_file_mode ();
  43 static int change_dir_mode ();
  44 static void describe_change ();
  45 static void usage ();
  46
  47 /* The name the program was run with. */
  48 char *program_name;
  49
  50 /* If nonzero, change the modes of directories recursively. */
  51 static int recurse;
  52
  53 /* If nonzero, force silence (no error messages). */
  54 static int force_silent;
  55
  56 /* If nonzero, describe the modes we set. */
  57 static int verbose;
  58
  59 /* If nonzero, describe only modes that change. */
  60 static int changes_only;
  61
  62 /* If non-zero, display usage information and exit.  */
  63 static int show_help;
  64
  65 /* If non-zero, print the version on standard output and exit.  */
  66 static int show_version;
  67
  68 static struct option const long_options[] =
  69 {
  70   {"recursive", no_argument, 0, 'R'},
  71   {"changes", no_argument, 0, 'c'},
  72   {"silent", no_argument, 0, 'f'},
  73   {"quiet", no_argument, 0, 'f'},
  74   {"verbose", no_argument, 0, 'v'},
  75   {"help", no_argument, &show_help, 1},
  76   {"version", no_argument, &show_version, 1},
  77   {0, 0, 0, 0}
  78 };
  79
  80 /* Parse the ASCII mode given on the command line into a linked list
  81    of `struct mode_change' and apply that to each file argument. */
  82
  83 void
  84 main (argc, argv)
  85      int argc;
  86      char **argv;
  87 {
  88   struct mode_change *changes;
  89   int errors = 0;
  90   int modeind = 0;              /* Index of the mode argument in `argv'. */
  91   int thisind;
  92   int c;
  93
  94   program_name = argv[0];
  95   recurse = force_silent = verbose = changes_only = 0;
  96
  97   while (1)
  98     {
  99       thisind = optind ? optind : 1;
 100
 101       c = getopt_long (argc, argv, "RcfvrwxXstugoa,+-=", long_options,
 102                        (int *) 0);
 103       if (c == EOF)
 104         break;
 105
 106       switch (c)
 107         {
 108         case 0:
 109           break;
 110         case 'r':
 111         case 'w':
 112         case 'x':
 113         case 'X':
 114         case 's':
 115         case 't':
 116         case 'u':
 117         case 'g':
 118         case 'o':
 119         case 'a':
 120         case ',':
 121         case '+':
 122         case '-':
 123         case '=':
 124           if (modeind != 0 && modeind != thisind)
 125             error (1, 0, "invalid mode");
 126           modeind = thisind;
 127           break;
 128         case 'R':
 129           recurse = 1;
 130           break;
 131         case 'c':
 132           verbose = 1;
 133           changes_only = 1;
 134           break;
 135         case 'f':
 136           force_silent = 1;
 137           break;
 138         case 'v':
 139           verbose = 1;
 140           break;
 141         default:
 142           usage (1);
 143         }
 144     }
 145
 146   if (show_version)
 147     {
 148       printf ("chmod - %s\n", version_string);
 149       exit (0);
 150     }
 151
 152   if (show_help)
 153     usage (0);
 154
 155   if (modeind == 0)
 156     modeind = optind++;
 157
 158   if (optind >= argc)
 159     {
 160       error (0, 0, "too few arguments");
 161       usage (1);
 162     }
 163
 164   changes = mode_compile (argv[modeind],
 165                           MODE_MASK_EQUALS | MODE_MASK_PLUS | MODE_MASK_MINUS);
 166   if (changes == MODE_INVALID)
 167     error (1, 0, "invalid mode");
 168   else if (changes == MODE_MEMORY_EXHAUSTED)
 169     error (1, 0, "virtual memory exhausted");
 170
 171   for (; optind < argc; ++optind)
 172     {
 173       strip_trailing_slashes (argv[optind]);
 174       errors |= change_file_mode (argv[optind], changes, 1);
 175     }
 176
 177   exit (errors);
 178 }
 179
 180 /* Change the mode of FILE according to the list of operations CHANGES.
 181    If DEREF_SYMLINK is non-zero and FILE is a symbolic link, change the
 182    mode of the referenced file.  If DEREF_SYMLINK is zero, ignore symbolic
 183    links.  Return 0 if successful, 1 if errors occurred. */
 184
 185 static int
 186 change_file_mode (file, changes, deref_symlink)
 187      char *file;
 188      struct mode_change *changes;
 189      int deref_symlink;
 190 {
 191   struct stat file_stats;
 192   unsigned short newmode;
 193   int errors = 0;
 194
 195   if (lstat (file, &file_stats))
 196     {
 197       if (force_silent == 0)
 198         error (0, errno, "%s", file);
 199       return 1;
 200     }
 201 #ifdef S_ISLNK
 202   if (S_ISLNK (file_stats.st_mode))
 203     {
 204       if (! deref_symlink)
 205         return 0;
 206       else
 207         if (stat (file, &file_stats))
 208           {
 209             if (force_silent == 0)
 210               error (0, errno, "%s", file);
 211             return 1;
 212           }
 213     }
 214 #endif
 215
 216   newmode = mode_adjust (file_stats.st_mode, changes);
 217
 218   if (newmode != (file_stats.st_mode & 07777))
 219     {
 220       if (verbose)
 221         describe_change (file, newmode, 1);
 222       if (chmod (file, (int) newmode))
 223         {
 224           if (force_silent == 0)
 225             error (0, errno, "%s", file);
 226           errors = 1;
 227         }
 228     }
 229   else if (verbose && changes_only == 0)
 230     describe_change (file, newmode, 0);
 231
 232   if (recurse && S_ISDIR (file_stats.st_mode))
 233     errors |= change_dir_mode (file, changes, &file_stats);
 234   return errors;
 235 }
 236
 237 /* Recursively change the modes of the files in directory DIR
 238    according to the list of operations CHANGES.
 239    STATP points to the results of lstat on DIR.
 240    Return 0 if successful, 1 if errors occurred. */
 241
 242 static int
 243 change_dir_mode (dir, changes, statp)
 244      char *dir;
 245      struct mode_change *changes;
 246      struct stat *statp;
 247 {
 248   char *name_space, *namep;
 249   char *path;                   /* Full path of each entry to process. */
 250   unsigned dirlength;           /* Length of DIR and '\0'. */
 251   unsigned filelength;          /* Length of each pathname to process. */
 252   unsigned pathlength;          /* Bytes allocated for `path'. */
 253   int errors = 0;
 254
 255   errno = 0;
 256   name_space = savedir (dir, statp->st_size);
 257   if (name_space == NULL)
 258     {
 259       if (errno)
 260         {
 261           if (force_silent == 0)
 262             error (0, errno, "%s", dir);
 263           return 1;
 264         }
 265       else
 266         error (1, 0, "virtual memory exhausted");
 267     }
 268
 269   dirlength = strlen (dir) + 1; /* + 1 is for the trailing '/'. */
 270   pathlength = dirlength + 1;
 271   /* Give `path' a dummy value; it will be reallocated before first use. */
 272   path = xmalloc (pathlength);
 273   strcpy (path, dir);
 274   path[dirlength - 1] = '/';
 275
 276   for (namep = name_space; *namep; namep += filelength - dirlength)
 277     {
 278       filelength = dirlength + strlen (namep) + 1;
 279       if (filelength > pathlength)
 280         {
 281           pathlength = filelength * 2;
 282           path = xrealloc (path, pathlength);
 283         }
 284       strcpy (path + dirlength, namep);
 285       errors |= change_file_mode (path, changes, 0);
 286     }
 287   free (path);
 288   free (name_space);
 289   return errors;
 290 }
 291
 292 /* Tell the user the mode MODE that file FILE has been set to;
 293    if CHANGED is zero, FILE had that mode already. */
 294
 295 static void
 296 describe_change (file, mode, changed)
 297      char *file;
 298      unsigned short mode;
 299      int changed;
 300 {
 301   char perms[11];               /* "-rwxrwxrwx" ls-style modes. */
 302
 303   mode_string (mode, perms);
 304   perms[10] = '\0';             /* `mode_string' does not null terminate. */
 305   if (changed)
 306     printf ("mode of %s changed to %04o (%s)\n",
 307             file, mode & 07777, &perms[1]);
 308   else
 309     printf ("mode of %s retained as %04o (%s)\n",
 310             file, mode & 07777, &perms[1]);
 311 }
 312
 313 static void
 314 usage (status)
 315      int status;
 316 {
 317   if (status != 0)
 318     fprintf (stderr, "Try `%s --help' for more information.\n",
 319              program_name);
 320   else
 321     {
 322       printf ("\
 323 Usage: %s [OPTION]... MODE[,MODE]... FILE...\n\
 324   or:  %s [OPTION]... OCTAL_MODE FILE...\n\
 325 ",
 326               program_name, program_name);
 327       printf ("\
 328 \n\
 329   -c, --changes           like verbose but report only when a change is made\n\
 330   -f, --silent, --quiet   suppress most error messages\n\
 331   -v, --verbose           output a diagnostic for every file processed\n\
 332   -R, --recursive         change files and directories recursively\n\
 333       --help              display this help and exit\n\
 334       --version           output version information and exit\n\
 335 \n\
 336 Each MODE is one or more of the letters ugoa, one of the symbols +-= and\n\
 337 one or more of the letters rwxXstugo.\n");
 338     }
 339   exit (status);
 340 }