src/mv.c

   1 /* mv -- move or rename files
   2    Copyright (C) 86, 89, 90, 91, 95, 1996 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 /* Options:
  19    -f, --force          Assume a 'y' answer to all questions it would
  20                         normally ask, and not ask the questions.
  21
  22    -i, --interactive    Require confirmation from the user before
  23                         performing any move that would destroy an
  24                         existing file.
  25
  26    -u, --update         Do not move a nondirectory that has an
  27                         existing destination with the same or newer
  28                         modification time.
  29
  30    -v, --verbose                List the name of each file as it is moved, and
  31                         the name it is moved to.
  32
  33    -b, --backup
  34    -S, --suffix
  35    -V, --version-control
  36                         Backup file creation.
  37
  38    Written by Mike Parker and David MacKenzie */
  39
  40 #ifdef _AIX
  41  #pragma alloca
  42 #endif
  43
  44 #include <config.h>
  45 #include <stdio.h>
  46 #include <getopt.h>
  47 #include <sys/types.h>
  48
  49 #include "system.h"
  50 #include "backupfile.h"
  51 #include "error.h"
  52
  53 #ifdef HAVE_LCHOWN
  54 # define chown(PATH, OWNER, GROUP) lchown(PATH, OWNER, GROUP)
  55 #endif
  56
  57 #ifndef _POSIX_VERSION
  58 uid_t geteuid ();
  59 #endif
  60
  61 char *basename ();
  62 enum backup_type get_version ();
  63 int isdir ();
  64 int yesno ();
  65 int safe_read ();
  66 int full_write ();
  67 void strip_trailing_slashes ();
  68 int euidaccess ();
  69 char *stpcpy ();
  70
  71 /* The name this program was run with. */
  72 char *program_name;
  73
  74 /* If nonzero, query the user before overwriting files. */
  75 static int interactive;
  76
  77 /* If nonzero, do not query the user before overwriting unwritable
  78    files. */
  79 static int override_mode;
  80
  81 /* If nonzero, do not move a nondirectory that has an existing destination
  82    with the same or newer modification time. */
  83 static int update = 0;
  84
  85 /* If nonzero, list each file as it is moved. */
  86 static int verbose;
  87
  88 /* If nonzero, stdin is a tty. */
  89 static int stdin_tty;
  90
  91 /* This process's effective user ID.  */
  92 static uid_t myeuid;
  93
  94 /* FIXME */
  95 static struct stat dest_stats, source_stats;
  96
  97 /* If nonzero, display usage information and exit.  */
  98 static int show_help;
  99
 100 /* If nonzero, print the version on standard output and exit.  */
 101 static int show_version;
 102
 103 static struct option const long_options[] =
 104 {
 105   {"backup", no_argument, NULL, 'b'},
 106   {"force", no_argument, NULL, 'f'},
 107   {"interactive", no_argument, NULL, 'i'},
 108   {"suffix", required_argument, NULL, 'S'},
 109   {"update", no_argument, &update, 1},
 110   {"verbose", no_argument, &verbose, 1},
 111   {"version-control", required_argument, NULL, 'V'},
 112   {"help", no_argument, &show_help, 1},
 113   {"version", no_argument, &show_version, 1},
 114   {NULL, 0, NULL, 0}
 115 };
 116
 117 /* If PATH is an existing directory, return nonzero, else 0.  */
 118
 119 static int
 120 is_real_dir (char *path)
 121 {
 122   struct stat stats;
 123
 124   return lstat (path, &stats) == 0 && S_ISDIR (stats.st_mode);
 125 }
 126
 127 /* Copy regular file SOURCE onto file DEST.
 128    Return 1 if an error occurred, 0 if successful. */
 129
 130 static int
 131 copy_reg (char *source, char *dest)
 132 {
 133   int ifd;
 134   int ofd;
 135   char buf[1024 * 8];
 136   int len;                      /* Number of bytes read into `buf'. */
 137
 138   if (!S_ISREG (source_stats.st_mode))
 139     {
 140       error (0, 0, _("cannot move `%s' across filesystems: Not a regular file"),
 141              source);
 142       return 1;
 143     }
 144
 145   if (unlink (dest) && errno != ENOENT)
 146     {
 147       error (0, errno, _("cannot remove `%s'"), dest);
 148       return 1;
 149     }
 150
 151   ifd = open (source, O_RDONLY, 0);
 152   if (ifd < 0)
 153     {
 154       error (0, errno, "%s", source);
 155       return 1;
 156     }
 157   ofd = open (dest, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 158   if (ofd < 0)
 159     {
 160       error (0, errno, "%s", dest);
 161       close (ifd);
 162       return 1;
 163     }
 164
 165   while ((len = safe_read (ifd, buf, sizeof (buf))) > 0)
 166     {
 167       if (full_write (ofd, buf, len) < 0)
 168         {
 169           error (0, errno, "%s", dest);
 170           close (ifd);
 171           close (ofd);
 172           unlink (dest);
 173           return 1;
 174         }
 175     }
 176   if (len < 0)
 177     {
 178       error (0, errno, "%s", source);
 179       close (ifd);
 180       close (ofd);
 181       unlink (dest);
 182       return 1;
 183     }
 184
 185   if (close (ifd) < 0)
 186     {
 187       error (0, errno, "%s", source);
 188       close (ofd);
 189       return 1;
 190     }
 191   if (close (ofd) < 0)
 192     {
 193       error (0, errno, "%s", dest);
 194       return 1;
 195     }
 196
 197   /* chown turns off set[ug]id bits for non-root,
 198      so do the chmod last.  */
 199
 200   /* Try to copy the old file's modtime and access time.  */
 201   {
 202     struct utimbuf tv;
 203
 204     tv.actime = source_stats.st_atime;
 205     tv.modtime = source_stats.st_mtime;
 206     if (utime (dest, &tv))
 207       {
 208         error (0, errno, "%s", dest);
 209         return 1;
 210       }
 211   }
 212
 213   /* Try to preserve ownership.  For non-root it might fail, but that's ok.
 214      But root probably wants to know, e.g. if NFS disallows it.  */
 215   if (chown (dest, source_stats.st_uid, source_stats.st_gid)
 216       && (errno != EPERM || myeuid == 0))
 217     {
 218       error (0, errno, "%s", dest);
 219       return 1;
 220     }
 221
 222   if (chmod (dest, source_stats.st_mode & 07777))
 223     {
 224       error (0, errno, "%s", dest);
 225       return 1;
 226     }
 227
 228   return 0;
 229 }
 230
 231 /* Move SOURCE onto DEST.  Handles cross-filesystem moves.
 232    If DEST is a directory, SOURCE must be also.
 233    Return 0 if successful, 1 if an error occurred.  */
 234
 235 static int
 236 do_move (char *source, char *dest)
 237 {
 238   char *dest_backup = NULL;
 239
 240   if (lstat (source, &source_stats) != 0)
 241     {
 242       error (0, errno, "%s", source);
 243       return 1;
 244     }
 245
 246   if (lstat (dest, &dest_stats) == 0)
 247     {
 248       if (source_stats.st_dev == dest_stats.st_dev
 249           && source_stats.st_ino == dest_stats.st_ino)
 250         {
 251           error (0, 0, _("`%s' and `%s' are the same file"), source, dest);
 252           return 1;
 253         }
 254
 255       if (S_ISDIR (dest_stats.st_mode))
 256         {
 257           error (0, 0, _("%s: cannot overwrite directory"), dest);
 258           return 1;
 259         }
 260
 261       if (!S_ISDIR (source_stats.st_mode) && update
 262           && source_stats.st_mtime <= dest_stats.st_mtime)
 263         return 0;
 264
 265       if (!override_mode && (interactive || stdin_tty)
 266           && euidaccess (dest, W_OK))
 267         {
 268           fprintf (stderr, _("%s: replace `%s', overriding mode %04o? "),
 269                    program_name, dest,
 270                    (unsigned int) (dest_stats.st_mode & 07777));
 271           if (!yesno ())
 272             return 0;
 273         }
 274       else if (interactive)
 275         {
 276           fprintf (stderr, _("%s: replace `%s'? "), program_name, dest);
 277           if (!yesno ())
 278             return 0;
 279         }
 280
 281       if (backup_type != none)
 282         {
 283           char *tmp_backup = find_backup_file_name (dest);
 284           if (tmp_backup == NULL)
 285             error (1, 0, _("virtual memory exhausted"));
 286           dest_backup = (char *) alloca (strlen (tmp_backup) + 1);
 287           strcpy (dest_backup, tmp_backup);
 288           free (tmp_backup);
 289           if (rename (dest, dest_backup))
 290             {
 291               if (errno != ENOENT)
 292                 {
 293                   error (0, errno, _("cannot backup `%s'"), dest);
 294                   return 1;
 295                 }
 296               else
 297                 dest_backup = NULL;
 298             }
 299         }
 300     }
 301   else if (errno != ENOENT)
 302     {
 303       error (0, errno, "%s", dest);
 304       return 1;
 305     }
 306
 307   if (verbose)
 308     printf ("%s -> %s\n", source, dest);
 309
 310   if (rename (source, dest) == 0)
 311     {
 312       return 0;
 313     }
 314
 315   if (errno != EXDEV)
 316     {
 317       error (0, errno, _("cannot move `%s' to `%s'"), source, dest);
 318       goto un_backup;
 319     }
 320
 321   /* rename failed on cross-filesystem link.  Copy the file instead. */
 322
 323   if (copy_reg (source, dest))
 324     goto un_backup;
 325
 326   if (unlink (source))
 327     {
 328       error (0, errno, _("cannot remove `%s'"), source);
 329       return 1;
 330     }
 331
 332   return 0;
 333
 334  un_backup:
 335   if (dest_backup)
 336     {
 337       if (rename (dest_backup, dest))
 338         error (0, errno, _("cannot un-backup `%s'"), dest);
 339     }
 340   return 1;
 341 }
 342
 343 /* Move file SOURCE onto DEST.  Handles the case when DEST is a directory.
 344    Return 0 if successful, 1 if an error occurred.  */
 345
 346 static int
 347 movefile (char *source, char *dest)
 348 {
 349   strip_trailing_slashes (source);
 350
 351   if ((dest[strlen (dest) - 1] == '/' && !is_real_dir (source))
 352       || isdir (dest))
 353     {
 354       /* Target is a directory; build full target filename. */
 355       char *base;
 356       char *new_dest;
 357
 358       base = basename (source);
 359       /* Remove a (single) trailing slash if there is at least one.  */
 360       if (dest[strlen (dest) - 1] == '/')
 361         dest[strlen (dest) - 1] = '\0';
 362       new_dest = (char *) alloca (strlen (dest) + 1 + strlen (base) + 1);
 363       stpcpy (stpcpy (stpcpy (new_dest, dest), "/"), base);
 364       return do_move (source, new_dest);
 365     }
 366   else
 367     return do_move (source, dest);
 368 }
 369
 370 static void
 371 usage (int status)
 372 {
 373   if (status != 0)
 374     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 375              program_name);
 376   else
 377     {
 378       printf (_("\
 379 Usage: %s [OPTION]... SOURCE DEST\n\
 380   or:  %s [OPTION]... SOURCE... DIRECTORY\n\
 381 "),
 382               program_name, program_name);
 383       printf (_("\
 384 Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY.\n\
 385 \n\
 386   -b, --backup                 make backup before removal\n\
 387   -f, --force                  remove existing destinations, never prompt\n\
 388   -i, --interactive            prompt before overwrite\n\
 389   -u, --update                 move only older or brand new files\n\
 390   -v, --verbose                explain what is being done\n\
 391   -S, --suffix=SUFFIX          override the usual backup suffix\n\
 392   -V, --version-control=WORD   override the usual version control\n\
 393       --help                   display this help and exit\n\
 394       --version                output version information and exit\n\
 395 \n\
 396 The backup suffix is ~, unless set with SIMPLE_BACKUP_SUFFIX.  The\n\
 397 version control may be set with VERSION_CONTROL, values are:\n\
 398 \n\
 399   t, numbered     make numbered backups\n\
 400   nil, existing   numbered if numbered backups exist, simple otherwise\n\
 401   never, simple   always make simple backups  \n"));
 402     }
 403   exit (status);
 404 }
 405
 406 int
 407 main (int argc, char **argv)
 408 {
 409   int c;
 410   int errors;
 411   int make_backups = 0;
 412   char *version;
 413
 414   program_name = argv[0];
 415   setlocale (LC_ALL, "");
 416   bindtextdomain (PACKAGE, LOCALEDIR);
 417   textdomain (PACKAGE);
 418
 419   version = getenv ("SIMPLE_BACKUP_SUFFIX");
 420   if (version)
 421     simple_backup_suffix = version;
 422   version = getenv ("VERSION_CONTROL");
 423
 424   myeuid = geteuid ();
 425   interactive = override_mode = verbose = update = 0;
 426   errors = 0;
 427
 428   while ((c = getopt_long (argc, argv, "bfiuvS:V:", long_options, (int *) 0))
 429          != EOF)
 430     {
 431       switch (c)
 432         {
 433         case 0:
 434           break;
 435         case 'b':
 436           make_backups = 1;
 437           break;
 438         case 'f':
 439           interactive = 0;
 440           override_mode = 1;
 441           break;
 442         case 'i':
 443           interactive = 1;
 444           override_mode = 0;
 445           break;
 446         case 'u':
 447           update = 1;
 448           break;
 449         case 'v':
 450           verbose = 1;
 451           break;
 452         case 'S':
 453           simple_backup_suffix = optarg;
 454           break;
 455         case 'V':
 456           version = optarg;
 457           break;
 458         default:
 459           usage (1);
 460         }
 461     }
 462
 463   if (show_version)
 464     {
 465       printf ("mv - %s\n", PACKAGE_VERSION);
 466       exit (0);
 467     }
 468
 469   if (show_help)
 470     usage (0);
 471
 472   if (argc < optind + 2)
 473     {
 474       error (0, 0, _("%s"), (argc == optind
 475                              ? _("missing file arguments")
 476                              : _("missing file argument")));
 477       usage (1);
 478     }
 479
 480   if (make_backups)
 481     backup_type = get_version (version);
 482
 483   stdin_tty = isatty (STDIN_FILENO);
 484
 485   if (argc > optind + 2 && !isdir (argv[argc - 1]))
 486     error (1, 0,
 487            _("when moving multiple files, last argument must be a directory"));
 488
 489   /* Move each arg but the last onto the last. */
 490   for (; optind < argc - 1; ++optind)
 491     errors |= movefile (argv[optind], argv[argc - 1]);
 492
 493   exit (errors);
 494 }