src/mv.c

   1 /* mv -- move or rename files
   2    Copyright (C) 1986, 1989, 1990, 1991, 1995 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
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, 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 "version.h"
  52 #include "error.h"
  53
  54 #ifndef _POSIX_VERSION
  55 uid_t geteuid ();
  56 #endif
  57
  58 char *basename ();
  59 enum backup_type get_version ();
  60 int isdir ();
  61 int yesno ();
  62 int safe_read ();
  63 int full_write ();
  64 void strip_trailing_slashes ();
  65 int euidaccess ();
  66 char *stpcpy ();
  67
  68 /* The name this program was run with. */
  69 char *program_name;
  70
  71 /* If nonzero, query the user before overwriting files. */
  72 static int interactive;
  73
  74 /* If nonzero, do not query the user before overwriting unwritable
  75    files. */
  76 static int override_mode;
  77
  78 /* If nonzero, do not move a nondirectory that has an existing destination
  79    with the same or newer modification time. */
  80 static int update = 0;
  81
  82 /* If nonzero, list each file as it is moved. */
  83 static int verbose;
  84
  85 /* If nonzero, stdin is a tty. */
  86 static int stdin_tty;
  87
  88 /* This process's effective user ID.  */
  89 static uid_t myeuid;
  90
  91 /* FIXME */
  92 static struct stat dest_stats, source_stats;
  93
  94 /* If nonzero, display usage information and exit.  */
  95 static int show_help;
  96
  97 /* If nonzero, print the version on standard output and exit.  */
  98 static int show_version;
  99
 100 static struct option const long_options[] =
 101 {
 102   {"backup", no_argument, NULL, 'b'},
 103   {"force", no_argument, NULL, 'f'},
 104   {"interactive", no_argument, NULL, 'i'},
 105   {"suffix", required_argument, NULL, 'S'},
 106   {"update", no_argument, &update, 1},
 107   {"verbose", no_argument, &verbose, 1},
 108   {"version-control", required_argument, NULL, 'V'},
 109   {"help", no_argument, &show_help, 1},
 110   {"version", no_argument, &show_version, 1},
 111   {NULL, 0, NULL, 0}
 112 };
 113
 114 /* If PATH is an existing directory, return nonzero, else 0.  */
 115
 116 static int
 117 is_real_dir (char *path)
 118 {
 119   struct stat stats;
 120
 121   return lstat (path, &stats) == 0 && S_ISDIR (stats.st_mode);
 122 }
 123
 124 /* Copy regular file SOURCE onto file DEST.
 125    Return 1 if an error occurred, 0 if successful. */
 126
 127 static int
 128 copy_reg (char *source, char *dest)
 129 {
 130   int ifd;
 131   int ofd;
 132   char buf[1024 * 8];
 133   int len;                      /* Number of bytes read into `buf'. */
 134
 135   if (!S_ISREG (source_stats.st_mode))
 136     {
 137       error (0, 0, _("cannot move `%s' across filesystems: Not a regular file"),
 138              source);
 139       return 1;
 140     }
 141
 142   if (unlink (dest) && errno != ENOENT)
 143     {
 144       error (0, errno, _("cannot remove `%s'"), dest);
 145       return 1;
 146     }
 147
 148   ifd = open (source, O_RDONLY, 0);
 149   if (ifd < 0)
 150     {
 151       error (0, errno, "%s", source);
 152       return 1;
 153     }
 154   ofd = open (dest, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 155   if (ofd < 0)
 156     {
 157       error (0, errno, "%s", dest);
 158       close (ifd);
 159       return 1;
 160     }
 161
 162   while ((len = safe_read (ifd, buf, sizeof (buf))) > 0)
 163     {
 164       if (full_write (ofd, buf, len) < 0)
 165         {
 166           error (0, errno, "%s", dest);
 167           close (ifd);
 168           close (ofd);
 169           unlink (dest);
 170           return 1;
 171         }
 172     }
 173   if (len < 0)
 174     {
 175       error (0, errno, "%s", source);
 176       close (ifd);
 177       close (ofd);
 178       unlink (dest);
 179       return 1;
 180     }
 181
 182   if (close (ifd) < 0)
 183     {
 184       error (0, errno, "%s", source);
 185       close (ofd);
 186       return 1;
 187     }
 188   if (close (ofd) < 0)
 189     {
 190       error (0, errno, "%s", dest);
 191       return 1;
 192     }
 193
 194   /* chown turns off set[ug]id bits for non-root,
 195      so do the chmod last.  */
 196
 197   /* Try to copy the old file's modtime and access time.  */
 198   {
 199     struct utimbuf tv;
 200
 201     tv.actime = source_stats.st_atime;
 202     tv.modtime = source_stats.st_mtime;
 203     if (utime (dest, &tv))
 204       {
 205         error (0, errno, "%s", dest);
 206         return 1;
 207       }
 208   }
 209
 210   /* Try to preserve ownership.  For non-root it might fail, but that's ok.
 211      But root probably wants to know, e.g. if NFS disallows it.  */
 212   if (chown (dest, source_stats.st_uid, source_stats.st_gid)
 213       && (errno != EPERM || myeuid == 0))
 214     {
 215       error (0, errno, "%s", dest);
 216       return 1;
 217     }
 218
 219   if (chmod (dest, source_stats.st_mode & 07777))
 220     {
 221       error (0, errno, "%s", dest);
 222       return 1;
 223     }
 224
 225   return 0;
 226 }
 227
 228 /* Move SOURCE onto DEST.  Handles cross-filesystem moves.
 229    If DEST is a directory, SOURCE must be also.
 230    Return 0 if successful, 1 if an error occurred.  */
 231
 232 static int
 233 do_move (char *source, char *dest)
 234 {
 235   char *dest_backup = NULL;
 236
 237   if (lstat (source, &source_stats) != 0)
 238     {
 239       error (0, errno, "%s", source);
 240       return 1;
 241     }
 242
 243   if (lstat (dest, &dest_stats) == 0)
 244     {
 245       if (source_stats.st_dev == dest_stats.st_dev
 246           && source_stats.st_ino == dest_stats.st_ino)
 247         {
 248           error (0, 0, _("`%s' and `%s' are the same file"), source, dest);
 249           return 1;
 250         }
 251
 252       if (S_ISDIR (dest_stats.st_mode))
 253         {
 254           error (0, 0, _("%s: cannot overwrite directory"), dest);
 255           return 1;
 256         }
 257
 258       if (!S_ISDIR (source_stats.st_mode) && update
 259           && source_stats.st_mtime <= dest_stats.st_mtime)
 260         return 0;
 261
 262       if (!override_mode && (interactive || stdin_tty)
 263           && euidaccess (dest, W_OK))
 264         {
 265           fprintf (stderr, _("%s: replace `%s', overriding mode %04o? "),
 266                    program_name, dest,
 267                    (unsigned int) (dest_stats.st_mode & 07777));
 268           if (!yesno ())
 269             return 0;
 270         }
 271       else if (interactive)
 272         {
 273           fprintf (stderr, _("%s: replace `%s'? "), program_name, dest);
 274           if (!yesno ())
 275             return 0;
 276         }
 277
 278       if (backup_type != none)
 279         {
 280           char *tmp_backup = find_backup_file_name (dest);
 281           if (tmp_backup == NULL)
 282             error (1, 0, _("virtual memory exhausted"));
 283           dest_backup = (char *) alloca (strlen (tmp_backup) + 1);
 284           strcpy (dest_backup, tmp_backup);
 285           free (tmp_backup);
 286           if (rename (dest, dest_backup))
 287             {
 288               if (errno != ENOENT)
 289                 {
 290                   error (0, errno, _("cannot backup `%s'"), dest);
 291                   return 1;
 292                 }
 293               else
 294                 dest_backup = NULL;
 295             }
 296         }
 297     }
 298   else if (errno != ENOENT)
 299     {
 300       error (0, errno, "%s", dest);
 301       return 1;
 302     }
 303
 304   if (verbose)
 305     printf ("%s -> %s\n", source, dest);
 306
 307   if (rename (source, dest) == 0)
 308     {
 309       return 0;
 310     }
 311
 312   if (errno != EXDEV)
 313     {
 314       error (0, errno, _("cannot move `%s' to `%s'"), source, dest);
 315       goto un_backup;
 316     }
 317
 318   /* rename failed on cross-filesystem link.  Copy the file instead. */
 319
 320   if (copy_reg (source, dest))
 321     goto un_backup;
 322
 323   if (unlink (source))
 324     {
 325       error (0, errno, _("cannot remove `%s'"), source);
 326       return 1;
 327     }
 328
 329   return 0;
 330
 331  un_backup:
 332   if (dest_backup)
 333     {
 334       if (rename (dest_backup, dest))
 335         error (0, errno, _("cannot un-backup `%s'"), dest);
 336     }
 337   return 1;
 338 }
 339
 340 /* Move file SOURCE onto DEST.  Handles the case when DEST is a directory.
 341    Return 0 if successful, 1 if an error occurred.  */
 342
 343 static int
 344 movefile (char *source, char *dest)
 345 {
 346   strip_trailing_slashes (source);
 347
 348   if ((dest[strlen (dest) - 1] == '/' && !is_real_dir (source))
 349       || isdir (dest))
 350     {
 351       /* Target is a directory; build full target filename. */
 352       char *base;
 353       char *new_dest;
 354
 355       base = basename (source);
 356       /* Remove a (single) trailing slash if there is at least one.  */
 357       if (dest[strlen (dest) - 1] == '/')
 358         dest[strlen (dest) - 1] = '\0';
 359       new_dest = (char *) alloca (strlen (dest) + 1 + strlen (base) + 1);
 360       stpcpy (stpcpy (stpcpy (new_dest, dest), "/"), base);
 361       return do_move (source, new_dest);
 362     }
 363   else
 364     return do_move (source, dest);
 365 }
 366
 367 static void
 368 usage (int status)
 369 {
 370   if (status != 0)
 371     fprintf (stderr, _("Try `%s --help' for more information.\n"),
 372              program_name);
 373   else
 374     {
 375       printf (_("\
 376 Usage: %s [OPTION]... SOURCE DEST\n\
 377   or:  %s [OPTION]... SOURCE... DIRECTORY\n\
 378 "),
 379               program_name, program_name);
 380       printf (_("\
 381 Rename SOURCE to DEST, or move SOURCE(s) to DIRECTORY.\n\
 382 \n\
 383   -b, --backup                 make backup before removal\n\
 384   -f, --force                  remove existing destinations, never prompt\n\
 385   -i, --interactive            prompt before overwrite\n\
 386   -u, --update                 move only older or brand new files\n\
 387   -v, --verbose                explain what is being done\n\
 388   -S, --suffix=SUFFIX          override the usual backup suffix\n\
 389   -V, --version-control=WORD   override the usual version control\n\
 390       --help                   display this help and exit\n\
 391       --version                output version information and exit\n\
 392 \n\
 393 The backup suffix is ~, unless set with SIMPLE_BACKUP_SUFFIX.  The\n\
 394 version control may be set with VERSION_CONTROL, values are:\n\
 395 \n\
 396   t, numbered     make numbered backups\n\
 397   nil, existing   numbered if numbered backups exist, simple otherwise\n\
 398   never, simple   always make simple backups  \n"));
 399     }
 400   exit (status);
 401 }
 402
 403 void
 404 main (int argc, char **argv)
 405 {
 406   int c;
 407   int errors;
 408   int make_backups = 0;
 409   char *version;
 410
 411   version = getenv ("SIMPLE_BACKUP_SUFFIX");
 412   if (version)
 413     simple_backup_suffix = version;
 414   version = getenv ("VERSION_CONTROL");
 415   program_name = argv[0];
 416   myeuid = geteuid ();
 417   interactive = override_mode = verbose = update = 0;
 418   errors = 0;
 419
 420   while ((c = getopt_long (argc, argv, "bfiuvS:V:", long_options, (int *) 0))
 421          != EOF)
 422     {
 423       switch (c)
 424         {
 425         case 0:
 426           break;
 427         case 'b':
 428           make_backups = 1;
 429           break;
 430         case 'f':
 431           interactive = 0;
 432           override_mode = 1;
 433           break;
 434         case 'i':
 435           interactive = 1;
 436           override_mode = 0;
 437           break;
 438         case 'u':
 439           update = 1;
 440           break;
 441         case 'v':
 442           verbose = 1;
 443           break;
 444         case 'S':
 445           simple_backup_suffix = optarg;
 446           break;
 447         case 'V':
 448           version = optarg;
 449           break;
 450         default:
 451           usage (1);
 452         }
 453     }
 454
 455   if (show_version)
 456     {
 457       printf ("mv - %s\n", version_string);
 458       exit (0);
 459     }
 460
 461   if (show_help)
 462     usage (0);
 463
 464   if (argc < optind + 2)
 465     {
 466       error (0, 0, _("missing file argument%s"), argc == optind ? "s" : "");
 467       usage (1);
 468     }
 469
 470   if (make_backups)
 471     backup_type = get_version (version);
 472
 473   stdin_tty = isatty (STDIN_FILENO);
 474
 475   if (argc > optind + 2 && !isdir (argv[argc - 1]))
 476     error (1, 0,
 477            _("when moving multiple files, last argument must be a directory"));
 478
 479   /* Move each arg but the last onto the last. */
 480   for (; optind < argc - 1; ++optind)
 481     errors |= movefile (argv[optind], argv[argc - 1]);
 482
 483   exit (errors);
 484 }