1 /* chmod -- change permission modes of files
2 Copyright (C) 89, 90, 91, 1995-2006 Free Software Foundation, Inc.
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)
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.
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
18 /* Written by David MacKenzie <djm@gnu.ai.mit.edu> */
23 #include <sys/types.h>
29 #include "modechange.h"
33 #include "root-dev-ino.h"
36 /* The official name of this program (e.g., no `g' prefix). */
37 #define PROGRAM_NAME "chmod"
39 #define AUTHORS "David MacKenzie", "Jim Meyering"
46 CH_NO_CHANGE_REQUESTED
51 /* Print a message for each file that is processed. */
54 /* Print a message for each file whose attributes we change. */
57 /* Do not be verbose. This is the default. */
61 /* The name the program was run with. */
64 /* The desired change to the mode. */
65 static struct mode_change *change;
67 /* The initial umask value, if it might be needed. */
68 static mode_t umask_value;
70 /* If true, change the modes of directories recursively. */
73 /* If true, force silence (no error messages). */
74 static bool force_silent;
76 /* If true, diagnose surprises from naive misuses like "chmod -r file".
77 POSIX allows diagnostics here, as portable code is supposed to use
78 "chmod -- -r file". */
79 static bool diagnose_surprises;
81 /* Level of verbosity. */
82 static enum Verbosity verbosity = V_off;
84 /* Pointer to the device and inode numbers of `/', when --recursive.
86 static struct dev_ino *root_dev_ino;
88 /* For long options that have no equivalent short option, use a
89 non-character as a pseudo short option, starting with CHAR_MAX + 1. */
92 NO_PRESERVE_ROOT = CHAR_MAX + 1,
97 static struct option const long_options[] =
99 {"changes", no_argument, NULL, 'c'},
100 {"recursive", no_argument, NULL, 'R'},
101 {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
102 {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
103 {"quiet", no_argument, NULL, 'f'},
104 {"reference", required_argument, NULL, REFERENCE_FILE_OPTION},
105 {"silent", no_argument, NULL, 'f'},
106 {"verbose", no_argument, NULL, 'v'},
107 {GETOPT_HELP_OPTION_DECL},
108 {GETOPT_VERSION_OPTION_DECL},
112 /* Return true if the chmodable permission bits of FILE changed.
113 The old mode was OLD_MODE, but it was changed to NEW_MODE. */
116 mode_changed (char const *file, mode_t old_mode, mode_t new_mode)
118 if (new_mode & (S_ISUID | S_ISGID | S_ISVTX))
120 /* The new mode contains unusual bits that the call to chmod may
121 have silently cleared. Check whether they actually changed. */
123 struct stat new_stats;
125 if (stat (file, &new_stats) != 0)
128 error (0, errno, _("getting new attributes of %s"), quote (file));
132 new_mode = new_stats.st_mode;
135 return ((old_mode ^ new_mode) & CHMOD_MODE_BITS) != 0;
138 /* Tell the user how/if the MODE of FILE has been changed.
139 CHANGED describes what (if anything) has happened. */
142 describe_change (const char *file, mode_t mode,
143 enum Change_status changed)
145 char perms[12]; /* "-rwxrwxrwx" ls-style modes. */
148 if (changed == CH_NOT_APPLIED)
150 printf (_("neither symbolic link %s nor referent has been changed\n"),
155 strmode (mode, perms);
156 perms[10] = '\0'; /* Remove trailing space. */
160 fmt = _("mode of %s changed to %04lo (%s)\n");
163 fmt = _("failed to change mode of %s to %04lo (%s)\n");
165 case CH_NO_CHANGE_REQUESTED:
166 fmt = _("mode of %s retained as %04lo (%s)\n");
171 printf (fmt, quote (file),
172 (unsigned long int) (mode & CHMOD_MODE_BITS), &perms[1]);
175 /* Change the mode of FILE.
176 Return true if successful. This function is called
177 once for every file system object that fts encounters. */
180 process_file (FTS *fts, FTSENT *ent)
182 char const *file_full_name = ent->fts_path;
183 char const *file = ent->fts_accpath;
184 const struct stat *file_stats = ent->fts_statp;
185 mode_t old_mode IF_LINT (= 0);
186 mode_t new_mode IF_LINT (= 0);
188 bool chmod_succeeded = false;
190 switch (ent->fts_info)
196 /* For a top-level file or directory, this FTS_NS (stat failed)
197 indicator is determined at the time of the initial fts_open call.
198 With programs like chmod, chown, and chgrp, that modify
199 permissions, it is possible that the file in question is
200 accessible when control reaches this point. So, if this is
201 the first time we've seen the FTS_NS for this file, tell
202 fts_read to stat it "again". */
203 if (ent->fts_level == 0 && ent->fts_number == 0)
206 fts_set (fts, ent, FTS_AGAIN);
209 error (0, ent->fts_errno, _("cannot access %s"), quote (file_full_name));
214 error (0, ent->fts_errno, _("%s"), quote (file_full_name));
219 error (0, ent->fts_errno, _("cannot read directory %s"),
220 quote (file_full_name));
228 if (ok && ROOT_DEV_INO_CHECK (root_dev_ino, file_stats))
230 ROOT_DEV_INO_WARN (file_full_name);
236 old_mode = file_stats->st_mode;
237 new_mode = mode_adjust (old_mode, S_ISDIR (old_mode) != 0, umask_value,
240 if (! S_ISLNK (old_mode))
242 if (chmodat (fts->fts_cwd_fd, file, new_mode) == 0)
243 chmod_succeeded = true;
247 error (0, errno, _("changing permissions of %s"),
248 quote (file_full_name));
254 if (verbosity != V_off)
256 bool changed = (chmod_succeeded
257 && mode_changed (file, old_mode, new_mode));
259 if (changed || verbosity == V_high)
261 enum Change_status ch_status =
263 : !chmod_succeeded ? CH_NOT_APPLIED
264 : !changed ? CH_NO_CHANGE_REQUESTED
266 describe_change (file_full_name, new_mode, ch_status);
270 if (chmod_succeeded & diagnose_surprises)
272 mode_t naively_expected_mode =
273 mode_adjust (old_mode, S_ISDIR (old_mode) != 0, 0, change, NULL);
274 if (new_mode & ~naively_expected_mode)
277 char naively_expected_perms[12];
278 strmode (new_mode, new_perms);
279 strmode (naively_expected_mode, naively_expected_perms);
280 new_perms[10] = naively_expected_perms[10] = '\0';
282 _("%s: new permissions are %s, not %s"),
283 quotearg_colon (file_full_name),
284 new_perms + 1, naively_expected_perms + 1);
290 fts_set (fts, ent, FTS_SKIP);
295 /* Recursively change the modes of the specified FILES (the last entry
296 of which is NULL). BIT_FLAGS controls how fts works.
297 Return true if successful. */
300 process_files (char **files, int bit_flags)
304 FTS *fts = xfts_open (files, bit_flags, NULL);
310 ent = fts_read (fts);
315 /* FIXME: try to give a better message */
316 error (0, errno, _("fts_read failed"));
322 ok &= process_file (fts, ent);
325 /* Ignore failure, since the only way it can do so is in failing to
326 return to the original directory, and since we're about to exit,
327 that doesn't matter. */
336 if (status != EXIT_SUCCESS)
337 fprintf (stderr, _("Try `%s --help' for more information.\n"),
342 Usage: %s [OPTION]... MODE[,MODE]... FILE...\n\
343 or: %s [OPTION]... OCTAL-MODE FILE...\n\
344 or: %s [OPTION]... --reference=RFILE FILE...\n\
346 program_name, program_name, program_name);
348 Change the mode of each FILE to MODE.\n\
350 -c, --changes like verbose but report only when a change is made\n\
353 --no-preserve-root do not treat `/' specially (the default)\n\
354 --preserve-root fail to operate recursively on `/'\n\
357 -f, --silent, --quiet suppress most error messages\n\
358 -v, --verbose output a diagnostic for every file processed\n\
359 --reference=RFILE use RFILE's mode instead of MODE values\n\
360 -R, --recursive change files and directories recursively\n\
362 fputs (HELP_OPTION_DESCRIPTION, stdout);
363 fputs (VERSION_OPTION_DESCRIPTION, stdout);
366 Each MODE is of the form `[ugoa]*([-+=]([rwxXst]*|[ugo]))+'.\n\
368 printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
373 /* Parse the ASCII mode given on the command line into a linked list
374 of `struct mode_change' and apply that to each file argument. */
377 main (int argc, char **argv)
381 size_t mode_alloc = 0;
383 bool preserve_root = false;
384 char const *reference_file = NULL;
387 initialize_main (&argc, &argv);
388 program_name = argv[0];
389 setlocale (LC_ALL, "");
390 bindtextdomain (PACKAGE, LOCALEDIR);
391 textdomain (PACKAGE);
393 atexit (close_stdout);
395 recurse = force_silent = diagnose_surprises = false;
397 while ((c = getopt_long (argc, argv,
398 "Rcfvr::w::x::X::s::t::u::g::o::a::,::+::=::",
417 /* Support nonportable uses like "chmod -w", but diagnose
418 surprises due to umask confusion. Even though "--", "--r",
419 etc., are valid modes, there is no "case '-'" here since
420 getopt_long reserves leading "--" for long options. */
422 /* Allocate a mode string (e.g., "-rwx") by concatenating
423 the argument containing this option. If a previous mode
424 string was given, concatenate the previous string, a
425 comma, and the new string (e.g., "-s,-rwx"). */
427 char const *arg = argv[optind - 1];
428 size_t arg_len = strlen (arg);
429 size_t mode_comma_len = mode_len + !!mode_len;
430 size_t new_mode_len = mode_comma_len + arg_len;
431 if (mode_alloc <= new_mode_len)
433 mode_alloc = new_mode_len + 1;
434 mode = X2REALLOC (mode, &mode_alloc);
436 mode[mode_len] = ',';
437 strcpy (mode + mode_comma_len, arg);
438 mode_len = new_mode_len;
440 diagnose_surprises = true;
443 case NO_PRESERVE_ROOT:
444 preserve_root = false;
447 preserve_root = true;
449 case REFERENCE_FILE_OPTION:
450 reference_file = optarg;
456 verbosity = V_changes_only;
464 case_GETOPT_HELP_CHAR;
465 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
467 usage (EXIT_FAILURE);
475 error (0, 0, _("cannot combine mode and --reference options"));
476 usage (EXIT_FAILURE);
482 mode = argv[optind++];
487 if (!mode || mode != argv[optind - 1])
488 error (0, 0, _("missing operand"));
490 error (0, 0, _("missing operand after %s"), quote (argv[argc - 1]));
491 usage (EXIT_FAILURE);
496 change = mode_create_from_ref (reference_file);
498 error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
499 quote (reference_file));
503 change = mode_compile (mode);
506 error (0, 0, _("invalid mode: %s"), quote (mode));
507 usage (EXIT_FAILURE);
509 umask_value = umask (0);
512 if (recurse & preserve_root)
514 static struct dev_ino dev_ino_buf;
515 root_dev_ino = get_root_dev_ino (&dev_ino_buf);
516 if (root_dev_ino == NULL)
517 error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
525 ok = process_files (argv + optind, FTS_COMFOLLOW | FTS_PHYSICAL);
527 exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);