src/rm.c

   1 /* `rm' file deletion utility for GNU.
   2    Copyright (C) 88, 90, 91, 1994-2005 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  17
  18 /* Written by Paul Rubin, David MacKenzie, and Richard Stallman.
  19    Reworked to use chdir and avoid recursion by Jim Meyering.  */
  20
  21 /* Implementation overview:
  22
  23    In the `usual' case, RM saves no state for directories it is processing.
  24    When a removal fails (either due to an error or to an interactive `no'
  25    reply), the failure is noted (see description of `ht' in remove.c's
  26    remove_cwd_entries function) so that when/if the containing directory
  27    is reopened, RM doesn't try to remove the entry again.
  28
  29    RM may delete arbitrarily deep hierarchies -- even ones in which file
  30    names (from root to leaf) are longer than the system-imposed maximum.
  31    It does this by using chdir to change to each directory in turn before
  32    removing the entries in that directory.
  33
  34    RM detects directory cycles lazily.  See lib/cycle-check.c.
  35
  36    RM is careful to avoid forming full file names whenever possible.
  37    A full file name is formed only when it is about to be used -- e.g.
  38    in a diagnostic or in an interactive-mode prompt.
  39
  40    RM minimizes the number of lstat system calls it makes.  On systems
  41    that have valid d_type data in directory entries, RM makes only one
  42    lstat call per command line argument -- regardless of the depth of
  43    the hierarchy.  */
  44
  45 #include <config.h>
  46 #include <stdio.h>
  47 #include <getopt.h>
  48 #include <sys/types.h>
  49 #include <assert.h>
  50
  51 #include "system.h"
  52 #include "dirname.h"
  53 #include "error.h"
  54 #include "lstat.h"
  55 #include "quote.h"
  56 #include "quotearg.h"
  57 #include "remove.h"
  58 #include "root-dev-ino.h"
  59
  60 /* The official name of this program (e.g., no `g' prefix).  */
  61 #define PROGRAM_NAME "rm"
  62
  63 #define AUTHORS \
  64   "Paul Rubin", "David MacKenzie, Richard Stallman", "Jim Meyering"
  65
  66 /* Name this program was run with.  */
  67 char *program_name;
  68
  69 /* For long options that have no equivalent short option, use a
  70    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  71 enum
  72 {
  73   NO_PRESERVE_ROOT = CHAR_MAX + 1,
  74   PRESERVE_ROOT,
  75   PRESUME_INPUT_TTY_OPTION
  76 };
  77
  78 static struct option const long_opts[] =
  79 {
  80   {"directory", no_argument, NULL, 'd'},
  81   {"force", no_argument, NULL, 'f'},
  82   {"interactive", no_argument, NULL, 'i'},
  83
  84   {"no-preserve-root", no_argument, NULL, NO_PRESERVE_ROOT},
  85   {"preserve-root", no_argument, NULL, PRESERVE_ROOT},
  86
  87   /* This is solely for testing.  Do not document.  */
  88   /* It is relatively difficult to ensure that there is a tty on stdin.
  89      Since rm acts differently depending on that, without this option,
  90      it'd be harder to test the parts of rm that depend on that setting.  */
  91   {"presume-input-tty", no_argument, NULL, PRESUME_INPUT_TTY_OPTION},
  92
  93   {"recursive", no_argument, NULL, 'r'},
  94   {"verbose", no_argument, NULL, 'v'},
  95   {GETOPT_HELP_OPTION_DECL},
  96   {GETOPT_VERSION_OPTION_DECL},
  97   {NULL, 0, NULL, 0}
  98 };
  99
 100 /* Advise the user about invalid usages like "rm -foo" if the file
 101    "-foo" exists, assuming ARGC and ARGV are as with `main'.  */
 102
 103 static void
 104 diagnose_leading_hyphen (int argc, char **argv)
 105 {
 106   /* OPTIND is unreliable, so iterate through the arguments looking
 107      for a file name that looks like an option.  */
 108   int i;
 109
 110   for (i = 1; i < argc; i++)
 111     {
 112       char const *arg = argv[i];
 113       struct stat st;
 114
 115       if (arg[0] == '-' && arg[1] && lstat (arg, &st) == 0)
 116         {
 117           fprintf (stderr,
 118                    _("Try `%s ./%s' to remove the file %s.\n"),
 119                    argv[0],
 120                    quotearg_n_style (1, shell_quoting_style, arg),
 121                    quote (arg));
 122           break;
 123         }
 124     }
 125 }
 126
 127 void
 128 usage (int status)
 129 {
 130   if (status != EXIT_SUCCESS)
 131     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 132              program_name);
 133   else
 134     {
 135       char *base = base_name (program_name);
 136       printf (_("Usage: %s [OPTION]... FILE...\n"), program_name);
 137       fputs (_("\
 138 Remove (unlink) the FILE(s).\n\
 139 \n\
 140   -d, --directory       unlink FILE, even if it is a non-empty directory\n\
 141                           (super-user only; this works only if your system\n\
 142                            supports `unlink' for nonempty directories)\n\
 143   -f, --force           ignore nonexistent files, never prompt\n\
 144   -i, --interactive     prompt before any removal\n\
 145 "), stdout);
 146       fputs (_("\
 147       --no-preserve-root do not treat `/' specially (the default)\n\
 148       --preserve-root   fail to operate recursively on `/'\n\
 149   -r, -R, --recursive   remove directories and their contents recursively\n\
 150   -v, --verbose         explain what is being done\n\
 151 "), stdout);
 152       fputs (HELP_OPTION_DESCRIPTION, stdout);
 153       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 154       fputs (_("\
 155 \n\
 156 By default, rm does not remove directories.  Use the --recursive (-r or -R)\n\
 157 option to remove each listed directory, too, along with all of its contents.\n\
 158 "), stdout);
 159       printf (_("\
 160 \n\
 161 To remove a file whose name starts with a `-', for example `-foo',\n\
 162 use one of these commands:\n\
 163   %s -- -foo\n\
 164 \n\
 165   %s ./-foo\n\
 166 "),
 167               base, base);
 168       fputs (_("\
 169 \n\
 170 Note that if you use rm to remove a file, it is usually possible to recover\n\
 171 the contents of that file.  If you want more assurance that the contents are\n\
 172 truly unrecoverable, consider using shred.\n\
 173 "), stdout);
 174       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
 175     }
 176   exit (status);
 177 }
 178
 179 static void
 180 rm_option_init (struct rm_options *x)
 181 {
 182   x->unlink_dirs = false;
 183   x->ignore_missing_files = false;
 184   x->interactive = false;
 185   x->recursive = false;
 186   x->root_dev_ino = NULL;
 187   x->stdin_tty = isatty (STDIN_FILENO);
 188   x->verbose = false;
 189
 190   /* Since this program exits immediately after calling `rm', rm need not
 191      expend unnecessary effort to preserve the initial working directory.  */
 192   x->require_restore_cwd = false;
 193 }
 194
 195 int
 196 main (int argc, char **argv)
 197 {
 198   bool preserve_root = false;
 199   struct rm_options x;
 200   int c;
 201
 202   initialize_main (&argc, &argv);
 203   program_name = argv[0];
 204   setlocale (LC_ALL, "");
 205   bindtextdomain (PACKAGE, LOCALEDIR);
 206   textdomain (PACKAGE);
 207
 208   atexit (close_stdout);
 209
 210   rm_option_init (&x);
 211
 212   while ((c = getopt_long (argc, argv, "dfirvR", long_opts, NULL)) != -1)
 213     {
 214       switch (c)
 215         {
 216         case 'd':
 217           x.unlink_dirs = true;
 218           break;
 219
 220         case 'f':
 221           x.interactive = false;
 222           x.ignore_missing_files = true;
 223           break;
 224
 225         case 'i':
 226           x.interactive = true;
 227           x.ignore_missing_files = false;
 228           break;
 229
 230         case 'r':
 231         case 'R':
 232           x.recursive = true;
 233           break;
 234
 235         case NO_PRESERVE_ROOT:
 236           preserve_root = false;
 237           break;
 238
 239         case PRESERVE_ROOT:
 240           preserve_root = true;
 241           break;
 242
 243         case PRESUME_INPUT_TTY_OPTION:
 244           x.stdin_tty = true;
 245           break;
 246
 247         case 'v':
 248           x.verbose = true;
 249           break;
 250
 251         case_GETOPT_HELP_CHAR;
 252         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 253         default:
 254           diagnose_leading_hyphen (argc, argv);
 255           usage (EXIT_FAILURE);
 256         }
 257     }
 258
 259   if (argc <= optind)
 260     {
 261       if (x.ignore_missing_files)
 262         exit (EXIT_SUCCESS);
 263       else
 264         {
 265           error (0, 0, _("missing operand"));
 266           usage (EXIT_FAILURE);
 267         }
 268     }
 269
 270   if (x.recursive & preserve_root)
 271     {
 272       static struct dev_ino dev_ino_buf;
 273       x.root_dev_ino = get_root_dev_ino (&dev_ino_buf);
 274       if (x.root_dev_ino == NULL)
 275         error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
 276                quote ("/"));
 277     }
 278
 279   {
 280     size_t n_files = argc - optind;
 281     char const *const *file = (char const *const *) argv + optind;
 282
 283     enum RM_status status = rm (n_files, file, &x);
 284     assert (VALID_STATUS (status));
 285     exit (status == RM_ERROR ? EXIT_FAILURE : EXIT_SUCCESS);
 286   }
 287 }