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