src/mv.c

   1 /* mv -- move or rename files
   2    Copyright (C) 1986-2013 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 3 of the License, or
   7    (at your option) 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, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Mike Parker, David MacKenzie, and Jim Meyering */
  18
  19 #include <config.h>
  20 #include <stdio.h>
  21 #include <getopt.h>
  22 #include <sys/types.h>
  23 #include <assert.h>
  24 #include <selinux/selinux.h>
  25
  26 #include "system.h"
  27 #include "backupfile.h"
  28 #include "copy.h"
  29 #include "cp-hash.h"
  30 #include "error.h"
  31 #include "filenamecat.h"
  32 #include "quote.h"
  33 #include "remove.h"
  34 #include "root-dev-ino.h"
  35 #include "priv-set.h"
  36
  37 /* The official name of this program (e.g., no 'g' prefix).  */
  38 #define PROGRAM_NAME "mv"
  39
  40 #define AUTHORS \
  41   proper_name ("Mike Parker"), \
  42   proper_name ("David MacKenzie"), \
  43   proper_name ("Jim Meyering")
  44
  45 /* For long options that have no equivalent short option, use a
  46    non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
  47 enum
  48 {
  49   STRIP_TRAILING_SLASHES_OPTION = CHAR_MAX + 1
  50 };
  51
  52 /* Remove any trailing slashes from each SOURCE argument.  */
  53 static bool remove_trailing_slashes;
  54
  55 static struct option const long_options[] =
  56 {
  57   {"backup", optional_argument, NULL, 'b'},
  58   {"force", no_argument, NULL, 'f'},
  59   {"interactive", no_argument, NULL, 'i'},
  60   {"no-clobber", no_argument, NULL, 'n'},
  61   {"no-target-directory", no_argument, NULL, 'T'},
  62   {"strip-trailing-slashes", no_argument, NULL, STRIP_TRAILING_SLASHES_OPTION},
  63   {"suffix", required_argument, NULL, 'S'},
  64   {"target-directory", required_argument, NULL, 't'},
  65   {"update", no_argument, NULL, 'u'},
  66   {"verbose", no_argument, NULL, 'v'},
  67   {GETOPT_HELP_OPTION_DECL},
  68   {GETOPT_VERSION_OPTION_DECL},
  69   {NULL, 0, NULL, 0}
  70 };
  71
  72 static void
  73 rm_option_init (struct rm_options *x)
  74 {
  75   x->ignore_missing_files = false;
  76   x->remove_empty_directories = true;
  77   x->recursive = true;
  78   x->one_file_system = false;
  79
  80   /* Should we prompt for removal, too?  No.  Prompting for the 'move'
  81      part is enough.  It implies removal.  */
  82   x->interactive = RMI_NEVER;
  83   x->stdin_tty = false;
  84
  85   x->verbose = false;
  86
  87   /* Since this program may well have to process additional command
  88      line arguments after any call to 'rm', that function must preserve
  89      the initial working directory, in case one of those is a
  90      '.'-relative name.  */
  91   x->require_restore_cwd = true;
  92
  93   {
  94     static struct dev_ino dev_ino_buf;
  95     x->root_dev_ino = get_root_dev_ino (&dev_ino_buf);
  96     if (x->root_dev_ino == NULL)
  97       error (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
  98              quote ("/"));
  99   }
 100 }
 101
 102 static void
 103 cp_option_init (struct cp_options *x)
 104 {
 105   bool selinux_enabled = (0 < is_selinux_enabled ());
 106
 107   cp_options_default (x);
 108   x->copy_as_regular = false;  /* FIXME: maybe make this an option */
 109   x->reflink_mode = REFLINK_NEVER;
 110   x->dereference = DEREF_NEVER;
 111   x->unlink_dest_before_opening = false;
 112   x->unlink_dest_after_failed_open = false;
 113   x->hard_link = false;
 114   x->interactive = I_UNSPECIFIED;
 115   x->move_mode = true;
 116   x->one_file_system = false;
 117   x->preserve_ownership = true;
 118   x->preserve_links = true;
 119   x->preserve_mode = true;
 120   x->preserve_timestamps = true;
 121   x->explicit_no_preserve_mode= false;
 122   x->preserve_security_context = selinux_enabled;
 123   x->reduce_diagnostics = false;
 124   x->data_copy_required = true;
 125   x->require_preserve = false;  /* FIXME: maybe make this an option */
 126   x->require_preserve_context = false;
 127   x->preserve_xattr = true;
 128   x->require_preserve_xattr = false;
 129   x->recursive = true;
 130   x->sparse_mode = SPARSE_AUTO;  /* FIXME: maybe make this an option */
 131   x->symbolic_link = false;
 132   x->set_mode = false;
 133   x->mode = 0;
 134   x->stdin_tty = isatty (STDIN_FILENO);
 135
 136   x->open_dangling_dest_symlink = false;
 137   x->update = false;
 138   x->verbose = false;
 139   x->dest_info = NULL;
 140   x->src_info = NULL;
 141 }
 142
 143 /* FILE is the last operand of this command.  Return true if FILE is a
 144    directory.  But report an error if there is a problem accessing FILE, other
 145    than nonexistence (errno == ENOENT).  */
 146
 147 static bool
 148 target_directory_operand (char const *file)
 149 {
 150   struct stat st;
 151   int err = (stat (file, &st) == 0 ? 0 : errno);
 152   bool is_a_dir = !err && S_ISDIR (st.st_mode);
 153   if (err && err != ENOENT)
 154     error (EXIT_FAILURE, err, _("accessing %s"), quote (file));
 155   return is_a_dir;
 156 }
 157
 158 /* Move SOURCE onto DEST.  Handles cross-file-system moves.
 159    If SOURCE is a directory, DEST must not exist.
 160    Return true if successful.  */
 161
 162 static bool
 163 do_move (const char *source, const char *dest, const struct cp_options *x)
 164 {
 165   bool copy_into_self;
 166   bool rename_succeeded;
 167   bool ok = copy (source, dest, false, x, &copy_into_self, &rename_succeeded);
 168
 169   if (ok)
 170     {
 171       char const *dir_to_remove;
 172       if (copy_into_self)
 173         {
 174           /* In general, when copy returns with copy_into_self set, SOURCE is
 175              the same as, or a parent of DEST.  In this case we know it's a
 176              parent.  It doesn't make sense to move a directory into itself, and
 177              besides in some situations doing so would give highly nonintuitive
 178              results.  Run this 'mkdir b; touch a c; mv * b' in an empty
 179              directory.  Here's the result of running echo $(find b -print):
 180              b b/a b/b b/b/a b/c.  Notice that only file 'a' was copied
 181              into b/b.  Handle this by giving a diagnostic, removing the
 182              copied-into-self directory, DEST ('b/b' in the example),
 183              and failing.  */
 184
 185           dir_to_remove = NULL;
 186           ok = false;
 187         }
 188       else if (rename_succeeded)
 189         {
 190           /* No need to remove anything.  SOURCE was successfully
 191              renamed to DEST.  Or the user declined to rename a file.  */
 192           dir_to_remove = NULL;
 193         }
 194       else
 195         {
 196           /* This may mean SOURCE and DEST referred to different devices.
 197              It may also conceivably mean that even though they referred
 198              to the same device, rename wasn't implemented for that device.
 199
 200              E.g., (from Joel N. Weber),
 201              [...] there might someday be cases where you can't rename
 202              but you can copy where the device name is the same, especially
 203              on Hurd.  Consider an ftpfs with a primitive ftp server that
 204              supports uploading, downloading and deleting, but not renaming.
 205
 206              Also, note that comparing device numbers is not a reliable
 207              check for 'can-rename'.  Some systems can be set up so that
 208              files from many different physical devices all have the same
 209              st_dev field.  This is a feature of some NFS mounting
 210              configurations.
 211
 212              We reach this point if SOURCE has been successfully copied
 213              to DEST.  Now we have to remove SOURCE.
 214
 215              This function used to resort to copying only when rename
 216              failed and set errno to EXDEV.  */
 217
 218           dir_to_remove = source;
 219         }
 220
 221       if (dir_to_remove != NULL)
 222         {
 223           struct rm_options rm_options;
 224           enum RM_status status;
 225           char const *dir[2];
 226
 227           rm_option_init (&rm_options);
 228           rm_options.verbose = x->verbose;
 229           dir[0] = dir_to_remove;
 230           dir[1] = NULL;
 231
 232           status = rm ((void*) dir, &rm_options);
 233           assert (VALID_STATUS (status));
 234           if (status == RM_ERROR)
 235             ok = false;
 236         }
 237     }
 238
 239   return ok;
 240 }
 241
 242 /* Move file SOURCE onto DEST.  Handles the case when DEST is a directory.
 243    Treat DEST as a directory if DEST_IS_DIR.
 244    Return true if successful.  */
 245
 246 static bool
 247 movefile (char *source, char *dest, bool dest_is_dir,
 248           const struct cp_options *x)
 249 {
 250   bool ok;
 251
 252   /* This code was introduced to handle the ambiguity in the semantics
 253      of mv that is induced by the varying semantics of the rename function.
 254      Some systems (e.g., GNU/Linux) have a rename function that honors a
 255      trailing slash, while others (like Solaris 5,6,7) have a rename
 256      function that ignores a trailing slash.  I believe the GNU/Linux
 257      rename semantics are POSIX and susv2 compliant.  */
 258
 259   if (remove_trailing_slashes)
 260     strip_trailing_slashes (source);
 261
 262   if (dest_is_dir)
 263     {
 264       /* Treat DEST as a directory; build the full filename.  */
 265       char const *src_basename = last_component (source);
 266       char *new_dest = file_name_concat (dest, src_basename, NULL);
 267       strip_trailing_slashes (new_dest);
 268       ok = do_move (source, new_dest, x);
 269       free (new_dest);
 270     }
 271   else
 272     {
 273       ok = do_move (source, dest, x);
 274     }
 275
 276   return ok;
 277 }
 278
 279 void
 280 usage (int status)
 281 {
 282   if (status != EXIT_SUCCESS)
 283     emit_try_help ();
 284   else
 285     {
 286       printf (_("\
 287 Usage: %s [OPTION]... [-T] SOURCE DEST\n\
 288   or:  %s [OPTION]... SOURCE... DIRECTORY\n\
 289   or:  %s [OPTION]... -t DIRECTORY SOURCE...\n\
 290 "),
 291               program_name, program_name, program_name);
 292       fputs (_("\
 293 Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY.\n\
 294 "), stdout);
 295
 296       emit_mandatory_arg_note ();
 297
 298       fputs (_("\
 299       --backup[=CONTROL]       make a backup of each existing destination file\
 300 \n\
 301   -b                           like --backup but does not accept an argument\n\
 302   -f, --force                  do not prompt before overwriting\n\
 303   -i, --interactive            prompt before overwrite\n\
 304   -n, --no-clobber             do not overwrite an existing file\n\
 305 If you specify more than one of -i, -f, -n, only the final one takes effect.\n\
 306 "), stdout);
 307       fputs (_("\
 308       --strip-trailing-slashes  remove any trailing slashes from each SOURCE\n\
 309                                  argument\n\
 310   -S, --suffix=SUFFIX          override the usual backup suffix\n\
 311 "), stdout);
 312       fputs (_("\
 313   -t, --target-directory=DIRECTORY  move all SOURCE arguments into DIRECTORY\n\
 314   -T, --no-target-directory    treat DEST as a normal file\n\
 315   -u, --update                 move only when the SOURCE file is newer\n\
 316                                  than the destination file or when the\n\
 317                                  destination file is missing\n\
 318   -v, --verbose                explain what is being done\n\
 319 "), stdout);
 320       fputs (HELP_OPTION_DESCRIPTION, stdout);
 321       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 322       fputs (_("\
 323 \n\
 324 The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.\n\
 325 The version control method may be selected via the --backup option or through\n\
 326 the VERSION_CONTROL environment variable.  Here are the values:\n\
 327 \n\
 328 "), stdout);
 329       fputs (_("\
 330   none, off       never make backups (even if --backup is given)\n\
 331   numbered, t     make numbered backups\n\
 332   existing, nil   numbered if numbered backups exist, simple otherwise\n\
 333   simple, never   always make simple backups\n\
 334 "), stdout);
 335       emit_ancillary_info ();
 336     }
 337   exit (status);
 338 }
 339
 340 int
 341 main (int argc, char **argv)
 342 {
 343   int c;
 344   bool ok;
 345   bool make_backups = false;
 346   char *backup_suffix_string;
 347   char *version_control_string = NULL;
 348   struct cp_options x;
 349   char *target_directory = NULL;
 350   bool no_target_directory = false;
 351   int n_files;
 352   char **file;
 353
 354   initialize_main (&argc, &argv);
 355   set_program_name (argv[0]);
 356   setlocale (LC_ALL, "");
 357   bindtextdomain (PACKAGE, LOCALEDIR);
 358   textdomain (PACKAGE);
 359
 360   atexit (close_stdin);
 361
 362   cp_option_init (&x);
 363
 364   /* Try to disable the ability to unlink a directory.  */
 365   priv_set_remove_linkdir ();
 366
 367   /* FIXME: consider not calling getenv for SIMPLE_BACKUP_SUFFIX unless
 368      we'll actually use backup_suffix_string.  */
 369   backup_suffix_string = getenv ("SIMPLE_BACKUP_SUFFIX");
 370
 371   while ((c = getopt_long (argc, argv, "bfint:uvS:T", long_options, NULL))
 372          != -1)
 373     {
 374       switch (c)
 375         {
 376         case 'b':
 377           make_backups = true;
 378           if (optarg)
 379             version_control_string = optarg;
 380           break;
 381         case 'f':
 382           x.interactive = I_ALWAYS_YES;
 383           break;
 384         case 'i':
 385           x.interactive = I_ASK_USER;
 386           break;
 387         case 'n':
 388           x.interactive = I_ALWAYS_NO;
 389           break;
 390         case STRIP_TRAILING_SLASHES_OPTION:
 391           remove_trailing_slashes = true;
 392           break;
 393         case 't':
 394           if (target_directory)
 395             error (EXIT_FAILURE, 0, _("multiple target directories specified"));
 396           else
 397             {
 398               struct stat st;
 399               if (stat (optarg, &st) != 0)
 400                 error (EXIT_FAILURE, errno, _("accessing %s"), quote (optarg));
 401               if (! S_ISDIR (st.st_mode))
 402                 error (EXIT_FAILURE, 0, _("target %s is not a directory"),
 403                        quote (optarg));
 404             }
 405           target_directory = optarg;
 406           break;
 407         case 'T':
 408           no_target_directory = true;
 409           break;
 410         case 'u':
 411           x.update = true;
 412           break;
 413         case 'v':
 414           x.verbose = true;
 415           break;
 416         case 'S':
 417           make_backups = true;
 418           backup_suffix_string = optarg;
 419           break;
 420         case_GETOPT_HELP_CHAR;
 421         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 422         default:
 423           usage (EXIT_FAILURE);
 424         }
 425     }
 426
 427   n_files = argc - optind;
 428   file = argv + optind;
 429
 430   if (n_files <= !target_directory)
 431     {
 432       if (n_files <= 0)
 433         error (0, 0, _("missing file operand"));
 434       else
 435         error (0, 0, _("missing destination file operand after %s"),
 436                quote (file[0]));
 437       usage (EXIT_FAILURE);
 438     }
 439
 440   if (no_target_directory)
 441     {
 442       if (target_directory)
 443         error (EXIT_FAILURE, 0,
 444                _("cannot combine --target-directory (-t) "
 445                  "and --no-target-directory (-T)"));
 446       if (2 < n_files)
 447         {
 448           error (0, 0, _("extra operand %s"), quote (file[2]));
 449           usage (EXIT_FAILURE);
 450         }
 451     }
 452   else if (!target_directory)
 453     {
 454       assert (2 <= n_files);
 455       if (target_directory_operand (file[n_files - 1]))
 456         target_directory = file[--n_files];
 457       else if (2 < n_files)
 458         error (EXIT_FAILURE, 0, _("target %s is not a directory"),
 459                quote (file[n_files - 1]));
 460     }
 461
 462   if (make_backups && x.interactive == I_ALWAYS_NO)
 463     {
 464       error (0, 0,
 465              _("options --backup and --no-clobber are mutually exclusive"));
 466       usage (EXIT_FAILURE);
 467     }
 468
 469   if (backup_suffix_string)
 470     simple_backup_suffix = xstrdup (backup_suffix_string);
 471
 472   x.backup_type = (make_backups
 473                    ? xget_version (_("backup type"),
 474                                    version_control_string)
 475                    : no_backups);
 476
 477   hash_init ();
 478
 479   if (target_directory)
 480     {
 481       int i;
 482
 483       /* Initialize the hash table only if we'll need it.
 484          The problem it is used to detect can arise only if there are
 485          two or more files to move.  */
 486       if (2 <= n_files)
 487         dest_info_init (&x);
 488
 489       ok = true;
 490       for (i = 0; i < n_files; ++i)
 491         ok &= movefile (file[i], target_directory, true, &x);
 492     }
 493   else
 494     ok = movefile (file[0], file[1], false, &x);
 495
 496   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 497 }