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