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Diffstat (limited to 'src/chmod.c')
| -rw-r--r-- | src/chmod.c | 532 |
1 files changed, 532 insertions, 0 deletions
diff --git a/src/chmod.c b/src/chmod.c new file mode 100644 index 0000000..028c882 --- /dev/null +++ b/src/chmod.c @@ -0,0 +1,532 @@ +/* chmod -- change permission modes of files + Copyright (C) 89, 90, 91, 1995-2006 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +/* Written by David MacKenzie <djm@gnu.ai.mit.edu> */ + +#include <config.h> +#include <stdio.h> +#include <getopt.h> +#include <sys/types.h> + +#include "system.h" +#include "dev-ino.h" +#include "error.h" +#include "filemode.h" +#include "modechange.h" +#include "openat.h" +#include "quote.h" +#include "quotearg.h" +#include "root-dev-ino.h" +#include "xfts.h" + +/* The official name of this program (e.g., no `g' prefix). */ +#define PROGRAM_NAME "chmod" + +#define AUTHORS "David MacKenzie", "Jim Meyering" + +enum Change_status +{ + CH_NOT_APPLIED, + CH_SUCCEEDED, + CH_FAILED, + CH_NO_CHANGE_REQUESTED +}; + +enum Verbosity +{ + /* Print a message for each file that is processed. */ + V_high, + + /* Print a message for each file whose attributes we change. */ + V_changes_only, + + /* Do not be verbose. This is the default. */ + V_off +}; + +/* The name the program was run with. */ +char *program_name; + +/* The desired change to the mode. */ +static struct mode_change *change; + +/* The initial umask value, if it might be needed. */ +static mode_t umask_value; + +/* If true, change the modes of directories recursively. */ +static bool recurse; + +/* If true, force silence (no error messages). */ +static bool force_silent; + +/* If true, diagnose surprises from naive misuses like "chmod -r file". + POSIX allows diagnostics here, as portable code is supposed to use + "chmod -- -r file". */ +static bool diagnose_surprises; + +/* Level of verbosity. */ +static enum Verbosity verbosity = V_off; + +/* Pointer to the device and inode numbers of `/', when --recursive. + Otherwise NULL. */ +static struct dev_ino *root_dev_ino; + +/* For long options that have no equivalent short option, use a + non-character as a pseudo short option, starting with CHAR_MAX + 1. */ +enum +{ + NO_PRESERVE_ROOT = CHAR_MAX + 1, + PRESERVE_ROOT, + REFERENCE_FILE_OPTION +}; + +static struct option const long_options[] = +{ + {"changes", no_argument, NULL, 'c'}, + {"recursive", no_argument, NULL, 'R'}, + {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT}, + {"preserve-root", no_argument, NULL, PRESERVE_ROOT}, + {"quiet", no_argument, NULL, 'f'}, + {"reference", required_argument, NULL, REFERENCE_FILE_OPTION}, + {"silent", no_argument, NULL, 'f'}, + {"verbose", no_argument, NULL, 'v'}, + {GETOPT_HELP_OPTION_DECL}, + {GETOPT_VERSION_OPTION_DECL}, + {NULL, 0, NULL, 0} +}; + +/* Return true if the chmodable permission bits of FILE changed. + The old mode was OLD_MODE, but it was changed to NEW_MODE. */ + +static bool +mode_changed (char const *file, mode_t old_mode, mode_t new_mode) +{ + if (new_mode & (S_ISUID | S_ISGID | S_ISVTX)) + { + /* The new mode contains unusual bits that the call to chmod may + have silently cleared. Check whether they actually changed. */ + + struct stat new_stats; + + if (stat (file, &new_stats) != 0) + { + if (!force_silent) + error (0, errno, _("getting new attributes of %s"), quote (file)); + return false; + } + + new_mode = new_stats.st_mode; + } + + return ((old_mode ^ new_mode) & CHMOD_MODE_BITS) != 0; +} + +/* Tell the user how/if the MODE of FILE has been changed. + CHANGED describes what (if anything) has happened. */ + +static void +describe_change (const char *file, mode_t mode, + enum Change_status changed) +{ + char perms[12]; /* "-rwxrwxrwx" ls-style modes. */ + const char *fmt; + + if (changed == CH_NOT_APPLIED) + { + printf (_("neither symbolic link %s nor referent has been changed\n"), + quote (file)); + return; + } + + strmode (mode, perms); + perms[10] = '\0'; /* Remove trailing space. */ + switch (changed) + { + case CH_SUCCEEDED: + fmt = _("mode of %s changed to %04lo (%s)\n"); + break; + case CH_FAILED: + fmt = _("failed to change mode of %s to %04lo (%s)\n"); + break; + case CH_NO_CHANGE_REQUESTED: + fmt = _("mode of %s retained as %04lo (%s)\n"); + break; + default: + abort (); + } + printf (fmt, quote (file), + (unsigned long int) (mode & CHMOD_MODE_BITS), &perms[1]); +} + +/* Change the mode of FILE. + Return true if successful. This function is called + once for every file system object that fts encounters. */ + +static bool +process_file (FTS *fts, FTSENT *ent) +{ + char const *file_full_name = ent->fts_path; + char const *file = ent->fts_accpath; + const struct stat *file_stats = ent->fts_statp; + mode_t old_mode IF_LINT (= 0); + mode_t new_mode IF_LINT (= 0); + bool ok = true; + bool chmod_succeeded = false; + + switch (ent->fts_info) + { + case FTS_DP: + return true; + + case FTS_NS: + /* For a top-level file or directory, this FTS_NS (stat failed) + indicator is determined at the time of the initial fts_open call. + With programs like chmod, chown, and chgrp, that modify + permissions, it is possible that the file in question is + accessible when control reaches this point. So, if this is + the first time we've seen the FTS_NS for this file, tell + fts_read to stat it "again". */ + if (ent->fts_level == 0 && ent->fts_number == 0) + { + ent->fts_number = 1; + fts_set (fts, ent, FTS_AGAIN); + return true; + } + error (0, ent->fts_errno, _("cannot access %s"), quote (file_full_name)); + ok = false; + break; + + case FTS_ERR: + error (0, ent->fts_errno, _("%s"), quote (file_full_name)); + ok = false; + break; + + case FTS_DNR: + error (0, ent->fts_errno, _("cannot read directory %s"), + quote (file_full_name)); + ok = false; + break; + + default: + break; + } + + if (ok && ROOT_DEV_INO_CHECK (root_dev_ino, file_stats)) + { + ROOT_DEV_INO_WARN (file_full_name); + /* Tell fts not to traverse into this hierarchy. */ + fts_set (fts, ent, FTS_SKIP); + /* Ensure that we do not process "/" on the second visit. */ + ent = fts_read (fts); + ok = false; + } + + if (ok) + { + old_mode = file_stats->st_mode; + new_mode = mode_adjust (old_mode, S_ISDIR (old_mode) != 0, umask_value, + change, NULL); + + if (! S_ISLNK (old_mode)) + { + if (chmodat (fts->fts_cwd_fd, file, new_mode) == 0) + chmod_succeeded = true; + else + { + if (! force_silent) + error (0, errno, _("changing permissions of %s"), + quote (file_full_name)); + ok = false; + } + } + } + + if (verbosity != V_off) + { + bool changed = (chmod_succeeded + && mode_changed (file, old_mode, new_mode)); + + if (changed || verbosity == V_high) + { + enum Change_status ch_status = + (!ok ? CH_FAILED + : !chmod_succeeded ? CH_NOT_APPLIED + : !changed ? CH_NO_CHANGE_REQUESTED + : CH_SUCCEEDED); + describe_change (file_full_name, new_mode, ch_status); + } + } + + if (chmod_succeeded & diagnose_surprises) + { + mode_t naively_expected_mode = + mode_adjust (old_mode, S_ISDIR (old_mode) != 0, 0, change, NULL); + if (new_mode & ~naively_expected_mode) + { + char new_perms[12]; + char naively_expected_perms[12]; + strmode (new_mode, new_perms); + strmode (naively_expected_mode, naively_expected_perms); + new_perms[10] = naively_expected_perms[10] = '\0'; + error (0, 0, + _("%s: new permissions are %s, not %s"), + quotearg_colon (file_full_name), + new_perms + 1, naively_expected_perms + 1); + ok = false; + } + } + + if ( ! recurse) + fts_set (fts, ent, FTS_SKIP); + + return ok; +} + +/* Recursively change the modes of the specified FILES (the last entry + of which is NULL). BIT_FLAGS controls how fts works. + Return true if successful. */ + +static bool +process_files (char **files, int bit_flags) +{ + bool ok = true; + + FTS *fts = xfts_open (files, bit_flags, NULL); + + while (1) + { + FTSENT *ent; + + ent = fts_read (fts); + if (ent == NULL) + { + if (errno != 0) + { + /* FIXME: try to give a better message */ + error (0, errno, _("fts_read failed")); + ok = false; + } + break; + } + + ok &= process_file (fts, ent); + } + + /* Ignore failure, since the only way it can do so is in failing to + return to the original directory, and since we're about to exit, + that doesn't matter. */ + fts_close (fts); + + return ok; +} + +void +usage (int status) +{ + if (status != EXIT_SUCCESS) + fprintf (stderr, _("Try `%s --help' for more information.\n"), + program_name); + else + { + printf (_("\ +Usage: %s [OPTION]... MODE[,MODE]... FILE...\n\ + or: %s [OPTION]... OCTAL-MODE FILE...\n\ + or: %s [OPTION]... --reference=RFILE FILE...\n\ +"), + program_name, program_name, program_name); + fputs (_("\ +Change the mode of each FILE to MODE.\n\ +\n\ + -c, --changes like verbose but report only when a change is made\n\ +"), stdout); + fputs (_("\ + --no-preserve-root do not treat `/' specially (the default)\n\ + --preserve-root fail to operate recursively on `/'\n\ +"), stdout); + fputs (_("\ + -f, --silent, --quiet suppress most error messages\n\ + -v, --verbose output a diagnostic for every file processed\n\ + --reference=RFILE use RFILE's mode instead of MODE values\n\ + -R, --recursive change files and directories recursively\n\ +"), stdout); + fputs (HELP_OPTION_DESCRIPTION, stdout); + fputs (VERSION_OPTION_DESCRIPTION, stdout); + fputs (_("\ +\n\ +Each MODE is of the form `[ugoa]*([-+=]([rwxXst]*|[ugo]))+'.\n\ +"), stdout); + printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT); + } + exit (status); +} + +/* Parse the ASCII mode given on the command line into a linked list + of `struct mode_change' and apply that to each file argument. */ + +int +main (int argc, char **argv) +{ + char *mode = NULL; + size_t mode_len = 0; + size_t mode_alloc = 0; + bool ok; + bool preserve_root = false; + char const *reference_file = NULL; + int c; + + initialize_main (&argc, &argv); + program_name = argv[0]; + setlocale (LC_ALL, ""); + bindtextdomain (PACKAGE, LOCALEDIR); + textdomain (PACKAGE); + + atexit (close_stdout); + + recurse = force_silent = diagnose_surprises = false; + + while ((c = getopt_long (argc, argv, + "Rcfvr::w::x::X::s::t::u::g::o::a::,::+::=::", + long_options, NULL)) + != -1) + { + switch (c) + { + case 'r': + case 'w': + case 'x': + case 'X': + case 's': + case 't': + case 'u': + case 'g': + case 'o': + case 'a': + case ',': + case '+': + case '=': + /* Support nonportable uses like "chmod -w", but diagnose + surprises due to umask confusion. Even though "--", "--r", + etc., are valid modes, there is no "case '-'" here since + getopt_long reserves leading "--" for long options. */ + { + /* Allocate a mode string (e.g., "-rwx") by concatenating + the argument containing this option. If a previous mode + string was given, concatenate the previous string, a + comma, and the new string (e.g., "-s,-rwx"). */ + + char const *arg = argv[optind - 1]; + size_t arg_len = strlen (arg); + size_t mode_comma_len = mode_len + !!mode_len; + size_t new_mode_len = mode_comma_len + arg_len; + if (mode_alloc <= new_mode_len) + { + mode_alloc = new_mode_len + 1; + mode = X2REALLOC (mode, &mode_alloc); + } + mode[mode_len] = ','; + strcpy (mode + mode_comma_len, arg); + mode_len = new_mode_len; + + diagnose_surprises = true; + } + break; + case NO_PRESERVE_ROOT: + preserve_root = false; + break; + case PRESERVE_ROOT: + preserve_root = true; + break; + case REFERENCE_FILE_OPTION: + reference_file = optarg; + break; + case 'R': + recurse = true; + break; + case 'c': + verbosity = V_changes_only; + break; + case 'f': + force_silent = true; + break; + case 'v': + verbosity = V_high; + break; + case_GETOPT_HELP_CHAR; + case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); + default: + usage (EXIT_FAILURE); + } + } + + if (reference_file) + { + if (mode) + { + error (0, 0, _("cannot combine mode and --reference options")); + usage (EXIT_FAILURE); + } + } + else + { + if (!mode) + mode = argv[optind++]; + } + + if (optind >= argc) + { + if (!mode || mode != argv[optind - 1]) + error (0, 0, _("missing operand")); + else + error (0, 0, _("missing operand after %s"), quote (argv[argc - 1])); + usage (EXIT_FAILURE); + } + + if (reference_file) + { + change = mode_create_from_ref (reference_file); + if (!change) + error (EXIT_FAILURE, errno, _("failed to get attributes of %s"), + quote (reference_file)); + } + else + { + change = mode_compile (mode); + if (!change) + { + error (0, 0, _("invalid mode: %s"), quote (mode)); + usage (EXIT_FAILURE); + } + umask_value = umask (0); + } + + if (recurse & preserve_root) + { + static struct dev_ino dev_ino_buf; + root_dev_ino = get_root_dev_ino (&dev_ino_buf); + if (root_dev_ino == NULL) + error (EXIT_FAILURE, errno, _("failed to get attributes of %s"), + quote ("/")); + } + else + { + root_dev_ino = NULL; + } + + ok = process_files (argv + optind, FTS_COMFOLLOW | FTS_PHYSICAL); + + exit (ok ? EXIT_SUCCESS : EXIT_FAILURE); +} |