src/mv.c

   1 /* mv -- move or rename files
   2    Copyright (C) 1986-2017 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 "die.h"
  31 #include "error.h"
  32 #include "filenamecat.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   {"context", no_argument, NULL, 'Z'},
  59   {"force", no_argument, NULL, 'f'},
  60   {"interactive", no_argument, NULL, 'i'},
  61   {"no-clobber", no_argument, NULL, 'n'},
  62   {"no-target-directory", no_argument, NULL, 'T'},
  63   {"strip-trailing-slashes", no_argument, NULL, STRIP_TRAILING_SLASHES_OPTION},
  64   {"suffix", required_argument, NULL, 'S'},
  65   {"target-directory", required_argument, NULL, 't'},
  66   {"update", no_argument, NULL, 'u'},
  67   {"verbose", no_argument, NULL, 'v'},
  68   {GETOPT_HELP_OPTION_DECL},
  69   {GETOPT_VERSION_OPTION_DECL},
  70   {NULL, 0, NULL, 0}
  71 };
  72
  73 static void
  74 rm_option_init (struct rm_options *x)
  75 {
  76   x->ignore_missing_files = false;
  77   x->remove_empty_directories = true;
  78   x->recursive = true;
  79   x->one_file_system = false;
  80
  81   /* Should we prompt for removal, too?  No.  Prompting for the 'move'
  82      part is enough.  It implies removal.  */
  83   x->interactive = RMI_NEVER;
  84   x->stdin_tty = false;
  85
  86   x->verbose = false;
  87
  88   /* Since this program may well have to process additional command
  89      line arguments after any call to 'rm', that function must preserve
  90      the initial working directory, in case one of those is a
  91      '.'-relative name.  */
  92   x->require_restore_cwd = true;
  93
  94   {
  95     static struct dev_ino dev_ino_buf;
  96     x->root_dev_ino = get_root_dev_ino (&dev_ino_buf);
  97     if (x->root_dev_ino == NULL)
  98       die (EXIT_FAILURE, errno, _("failed to get attributes of %s"),
  99            quoteaf ("/"));
 100   }
 101 }
 102
 103 static void
 104 cp_option_init (struct cp_options *x)
 105 {
 106   bool selinux_enabled = (0 < is_selinux_enabled ());
 107
 108   cp_options_default (x);
 109   x->copy_as_regular = false;  /* FIXME: maybe make this an option */
 110   x->reflink_mode = REFLINK_AUTO;
 111   x->dereference = DEREF_NEVER;
 112   x->unlink_dest_before_opening = false;
 113   x->unlink_dest_after_failed_open = false;
 114   x->hard_link = false;
 115   x->interactive = I_UNSPECIFIED;
 116   x->move_mode = true;
 117   x->install_mode = false;
 118   x->one_file_system = false;
 119   x->preserve_ownership = true;
 120   x->preserve_links = true;
 121   x->preserve_mode = true;
 122   x->preserve_timestamps = true;
 123   x->explicit_no_preserve_mode= false;
 124   x->preserve_security_context = selinux_enabled;
 125   x->set_security_context = false;
 126   x->reduce_diagnostics = false;
 127   x->data_copy_required = true;
 128   x->require_preserve = false;  /* FIXME: maybe make this an option */
 129   x->require_preserve_context = false;
 130   x->preserve_xattr = true;
 131   x->require_preserve_xattr = false;
 132   x->recursive = true;
 133   x->sparse_mode = SPARSE_AUTO;  /* FIXME: maybe make this an option */
 134   x->symbolic_link = false;
 135   x->set_mode = false;
 136   x->mode = 0;
 137   x->stdin_tty = isatty (STDIN_FILENO);
 138
 139   x->open_dangling_dest_symlink = false;
 140   x->update = false;
 141   x->verbose = false;
 142   x->dest_info = NULL;
 143   x->src_info = NULL;
 144 }
 145
 146 /* FILE is the last operand of this command.  Return true if FILE is a
 147    directory.  But report an error if there is a problem accessing FILE, other
 148    than nonexistence (errno == ENOENT).  */
 149
 150 static bool
 151 target_directory_operand (char const *file)
 152 {
 153   struct stat st;
 154   int err = (stat (file, &st) == 0 ? 0 : errno);
 155   bool is_a_dir = !err && S_ISDIR (st.st_mode);
 156   if (err && err != ENOENT)
 157     die (EXIT_FAILURE, err, _("failed to access %s"), quoteaf (file));
 158   return is_a_dir;
 159 }
 160
 161 /* Move SOURCE onto DEST.  Handles cross-file-system moves.
 162    If SOURCE is a directory, DEST must not exist.
 163    Return true if successful.  */
 164
 165 static bool
 166 do_move (const char *source, const char *dest, const struct cp_options *x)
 167 {
 168   bool copy_into_self;
 169   bool rename_succeeded;
 170   bool ok = copy (source, dest, false, x, &copy_into_self, &rename_succeeded);
 171
 172   if (ok)
 173     {
 174       char const *dir_to_remove;
 175       if (copy_into_self)
 176         {
 177           /* In general, when copy returns with copy_into_self set, SOURCE is
 178              the same as, or a parent of DEST.  In this case we know it's a
 179              parent.  It doesn't make sense to move a directory into itself, and
 180              besides in some situations doing so would give highly nonintuitive
 181              results.  Run this 'mkdir b; touch a c; mv * b' in an empty
 182              directory.  Here's the result of running echo $(find b -print):
 183              b b/a b/b b/b/a b/c.  Notice that only file 'a' was copied
 184              into b/b.  Handle this by giving a diagnostic, removing the
 185              copied-into-self directory, DEST ('b/b' in the example),
 186              and failing.  */
 187
 188           dir_to_remove = NULL;
 189           ok = false;
 190         }
 191       else if (rename_succeeded)
 192         {
 193           /* No need to remove anything.  SOURCE was successfully
 194              renamed to DEST.  Or the user declined to rename a file.  */
 195           dir_to_remove = NULL;
 196         }
 197       else
 198         {
 199           /* This may mean SOURCE and DEST referred to different devices.
 200              It may also conceivably mean that even though they referred
 201              to the same device, rename wasn't implemented for that device.
 202
 203              E.g., (from Joel N. Weber),
 204              [...] there might someday be cases where you can't rename
 205              but you can copy where the device name is the same, especially
 206              on Hurd.  Consider an ftpfs with a primitive ftp server that
 207              supports uploading, downloading and deleting, but not renaming.
 208
 209              Also, note that comparing device numbers is not a reliable
 210              check for 'can-rename'.  Some systems can be set up so that
 211              files from many different physical devices all have the same
 212              st_dev field.  This is a feature of some NFS mounting
 213              configurations.
 214
 215              We reach this point if SOURCE has been successfully copied
 216              to DEST.  Now we have to remove SOURCE.
 217
 218              This function used to resort to copying only when rename
 219              failed and set errno to EXDEV.  */
 220
 221           dir_to_remove = source;
 222         }
 223
 224       if (dir_to_remove != NULL)
 225         {
 226           struct rm_options rm_options;
 227           enum RM_status status;
 228           char const *dir[2];
 229
 230           rm_option_init (&rm_options);
 231           rm_options.verbose = x->verbose;
 232           dir[0] = dir_to_remove;
 233           dir[1] = NULL;
 234
 235           status = rm ((void*) dir, &rm_options);
 236           assert (VALID_STATUS (status));
 237           if (status == RM_ERROR)
 238             ok = false;
 239         }
 240     }
 241
 242   return ok;
 243 }
 244
 245 /* Move file SOURCE onto DEST.  Handles the case when DEST is a directory.
 246    Treat DEST as a directory if DEST_IS_DIR.
 247    Return true if successful.  */
 248
 249 static bool
 250 movefile (char *source, char *dest, bool dest_is_dir,
 251           const struct cp_options *x)
 252 {
 253   bool ok;
 254
 255   /* This code was introduced to handle the ambiguity in the semantics
 256      of mv that is induced by the varying semantics of the rename function.
 257      Some systems (e.g., GNU/Linux) have a rename function that honors a
 258      trailing slash, while others (like Solaris 5,6,7) have a rename
 259      function that ignores a trailing slash.  I believe the GNU/Linux
 260      rename semantics are POSIX and susv2 compliant.  */
 261
 262   if (remove_trailing_slashes)
 263     strip_trailing_slashes (source);
 264
 265   if (dest_is_dir)
 266     {
 267       /* Treat DEST as a directory; build the full filename.  */
 268       char const *src_basename = last_component (source);
 269       char *new_dest = file_name_concat (dest, src_basename, NULL);
 270       strip_trailing_slashes (new_dest);
 271       ok = do_move (source, new_dest, x);
 272       free (new_dest);
 273     }
 274   else
 275     {
 276       ok = do_move (source, dest, x);
 277     }
 278
 279   return ok;
 280 }
 281
 282 void
 283 usage (int status)
 284 {
 285   if (status != EXIT_SUCCESS)
 286     emit_try_help ();
 287   else
 288     {
 289       printf (_("\
 290 Usage: %s [OPTION]... [-T] SOURCE DEST\n\
 291   or:  %s [OPTION]... SOURCE... DIRECTORY\n\
 292   or:  %s [OPTION]... -t DIRECTORY SOURCE...\n\
 293 "),
 294               program_name, program_name, program_name);
 295       fputs (_("\
 296 Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY.\n\
 297 "), stdout);
 298
 299       emit_mandatory_arg_note ();
 300
 301       fputs (_("\
 302       --backup[=CONTROL]       make a backup of each existing destination file\
 303 \n\
 304   -b                           like --backup but does not accept an argument\n\
 305   -f, --force                  do not prompt before overwriting\n\
 306   -i, --interactive            prompt before overwrite\n\
 307   -n, --no-clobber             do not overwrite an existing file\n\
 308 If you specify more than one of -i, -f, -n, only the final one takes effect.\n\
 309 "), stdout);
 310       fputs (_("\
 311       --strip-trailing-slashes  remove any trailing slashes from each SOURCE\n\
 312                                  argument\n\
 313   -S, --suffix=SUFFIX          override the usual backup suffix\n\
 314 "), stdout);
 315       fputs (_("\
 316   -t, --target-directory=DIRECTORY  move all SOURCE arguments into DIRECTORY\n\
 317   -T, --no-target-directory    treat DEST as a normal file\n\
 318   -u, --update                 move only when the SOURCE file is newer\n\
 319                                  than the destination file or when the\n\
 320                                  destination file is missing\n\
 321   -v, --verbose                explain what is being done\n\
 322   -Z, --context                set SELinux security context of destination\n\
 323                                  file to default type\n\
 324 "), stdout);
 325       fputs (HELP_OPTION_DESCRIPTION, stdout);
 326       fputs (VERSION_OPTION_DESCRIPTION, stdout);
 327       emit_backup_suffix_note ();
 328       emit_ancillary_info (PROGRAM_NAME);
 329     }
 330   exit (status);
 331 }
 332
 333 int
 334 main (int argc, char **argv)
 335 {
 336   int c;
 337   bool ok;
 338   bool make_backups = false;
 339   char *version_control_string = NULL;
 340   struct cp_options x;
 341   char *target_directory = NULL;
 342   bool no_target_directory = false;
 343   int n_files;
 344   char **file;
 345   bool selinux_enabled = (0 < is_selinux_enabled ());
 346
 347   initialize_main (&argc, &argv);
 348   set_program_name (argv[0]);
 349   setlocale (LC_ALL, "");
 350   bindtextdomain (PACKAGE, LOCALEDIR);
 351   textdomain (PACKAGE);
 352
 353   atexit (close_stdin);
 354
 355   cp_option_init (&x);
 356
 357   /* Try to disable the ability to unlink a directory.  */
 358   priv_set_remove_linkdir ();
 359
 360   while ((c = getopt_long (argc, argv, "bfint:uvS:TZ", long_options, NULL))
 361          != -1)
 362     {
 363       switch (c)
 364         {
 365         case 'b':
 366           make_backups = true;
 367           if (optarg)
 368             version_control_string = optarg;
 369           break;
 370         case 'f':
 371           x.interactive = I_ALWAYS_YES;
 372           break;
 373         case 'i':
 374           x.interactive = I_ASK_USER;
 375           break;
 376         case 'n':
 377           x.interactive = I_ALWAYS_NO;
 378           break;
 379         case STRIP_TRAILING_SLASHES_OPTION:
 380           remove_trailing_slashes = true;
 381           break;
 382         case 't':
 383           if (target_directory)
 384             die (EXIT_FAILURE, 0, _("multiple target directories specified"));
 385           else
 386             {
 387               struct stat st;
 388               if (stat (optarg, &st) != 0)
 389                 die (EXIT_FAILURE, errno, _("failed to access %s"),
 390                      quoteaf (optarg));
 391               if (! S_ISDIR (st.st_mode))
 392                 die (EXIT_FAILURE, 0, _("target %s is not a directory"),
 393                      quoteaf (optarg));
 394             }
 395           target_directory = optarg;
 396           break;
 397         case 'T':
 398           no_target_directory = true;
 399           break;
 400         case 'u':
 401           x.update = true;
 402           break;
 403         case 'v':
 404           x.verbose = true;
 405           break;
 406         case 'S':
 407           make_backups = true;
 408           simple_backup_suffix = optarg;
 409           break;
 410         case 'Z':
 411           /* As a performance enhancement, don't even bother trying
 412              to "restorecon" when not on an selinux-enabled kernel.  */
 413           if (selinux_enabled)
 414             {
 415               x.preserve_security_context = false;
 416               x.set_security_context = true;
 417             }
 418           break;
 419         case_GETOPT_HELP_CHAR;
 420         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 421         default:
 422           usage (EXIT_FAILURE);
 423         }
 424     }
 425
 426   n_files = argc - optind;
 427   file = argv + optind;
 428
 429   if (n_files <= !target_directory)
 430     {
 431       if (n_files <= 0)
 432         error (0, 0, _("missing file operand"));
 433       else
 434         error (0, 0, _("missing destination file operand after %s"),
 435                quoteaf (file[0]));
 436       usage (EXIT_FAILURE);
 437     }
 438
 439   if (no_target_directory)
 440     {
 441       if (target_directory)
 442         die (EXIT_FAILURE, 0,
 443              _("cannot combine --target-directory (-t) "
 444                "and --no-target-directory (-T)"));
 445       if (2 < n_files)
 446         {
 447           error (0, 0, _("extra operand %s"), quoteaf (file[2]));
 448           usage (EXIT_FAILURE);
 449         }
 450     }
 451   else if (!target_directory)
 452     {
 453       assert (2 <= n_files);
 454       if (target_directory_operand (file[n_files - 1]))
 455         target_directory = file[--n_files];
 456       else if (2 < n_files)
 457         die (EXIT_FAILURE, 0, _("target %s is not a directory"),
 458              quoteaf (file[n_files - 1]));
 459     }
 460
 461   if (make_backups && x.interactive == I_ALWAYS_NO)
 462     {
 463       error (0, 0,
 464              _("options --backup and --no-clobber are mutually exclusive"));
 465       usage (EXIT_FAILURE);
 466     }
 467
 468   x.backup_type = (make_backups
 469                    ? xget_version (_("backup type"),
 470                                    version_control_string)
 471                    : no_backups);
 472
 473   hash_init ();
 474
 475   if (target_directory)
 476     {
 477       int i;
 478
 479       /* Initialize the hash table only if we'll need it.
 480          The problem it is used to detect can arise only if there are
 481          two or more files to move.  */
 482       if (2 <= n_files)
 483         dest_info_init (&x);
 484
 485       ok = true;
 486       for (i = 0; i < n_files; ++i)
 487         ok &= movefile (file[i], target_directory, true, &x);
 488     }
 489   else
 490     ok = movefile (file[0], file[1], false, &x);
 491
 492   return ok ? EXIT_SUCCESS : EXIT_FAILURE;
 493 }