src/mv.c

   1 /* mv -- move or rename files
   2    Copyright (C) 1986, 1989, 1990, 1991 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 #ifdef HAVE_CONFIG_H
  45 #if defined (CONFIG_BROKETS)
  46 /* We use <config.h> instead of "config.h" so that a compilation
  47    using -I. -I$srcdir will use ./config.h rather than $srcdir/config.h
  48    (which it would do because it found this file in $srcdir).  */
  49 #include <config.h>
  50 #else
  51 #include "config.h"
  52 #endif
  53 #endif
  54
  55 #include <stdio.h>
  56 #include <getopt.h>
  57 #include <sys/types.h>
  58 #include "system.h"
  59 #include "backupfile.h"
  60 #include "version.h"
  61
  62 #ifndef _POSIX_VERSION
  63 uid_t geteuid ();
  64 #endif
  65
  66 char *basename ();
  67 enum backup_type get_version ();
  68 int isdir ();
  69 int yesno ();
  70 void error ();
  71 void strip_trailing_slashes ();
  72 int eaccess_stat ();
  73 char *stpcpy ();
  74
  75 static int copy_reg ();
  76 static int do_move ();
  77 static int movefile ();
  78 static void usage ();
  79
  80 /* The name this program was run with. */
  81 char *program_name;
  82
  83 /* If nonzero, query the user before overwriting files. */
  84 static int interactive;
  85
  86 /* If nonzero, do not query the user before overwriting unwritable
  87    files. */
  88 static int override_mode;
  89
  90 /* If nonzero, do not move a nondirectory that has an existing destination
  91    with the same or newer modification time. */
  92 static int update = 0;
  93
  94 /* If nonzero, list each file as it is moved. */
  95 static int verbose;
  96
  97 /* If nonzero, stdin is a tty. */
  98 static int stdin_tty;
  99
 100 /* This process's effective user ID.  */
 101 static uid_t myeuid;
 102
 103 /* If non-zero, display usage information and exit.  */
 104 static int show_help;
 105
 106 /* If non-zero, print the version on standard output and exit.  */
 107 static int show_version;
 108
 109 static struct option const long_options[] =
 110 {
 111   {"backup", no_argument, NULL, 'b'},
 112   {"force", no_argument, NULL, 'f'},
 113   {"interactive", no_argument, NULL, 'i'},
 114   {"suffix", required_argument, NULL, 'S'},
 115   {"update", no_argument, &update, 1},
 116   {"verbose", no_argument, &verbose, 1},
 117   {"version-control", required_argument, NULL, 'V'},
 118   {"help", no_argument, &show_help, 1},
 119   {"version", no_argument, &show_version, 1},
 120   {NULL, 0, NULL, 0}
 121 };
 122
 123 void
 124 main (argc, argv)
 125      int argc;
 126      char **argv;
 127 {
 128   int c;
 129   int errors;
 130   int make_backups = 0;
 131   char *version;
 132
 133   version = getenv ("SIMPLE_BACKUP_SUFFIX");
 134   if (version)
 135     simple_backup_suffix = version;
 136   version = getenv ("VERSION_CONTROL");
 137   program_name = argv[0];
 138   myeuid = geteuid ();
 139   interactive = override_mode = verbose = update = 0;
 140   errors = 0;
 141
 142   while ((c = getopt_long (argc, argv, "bfiuvS:V:", long_options, (int *) 0))
 143          != EOF)
 144     {
 145       switch (c)
 146         {
 147         case 0:
 148           break;
 149         case 'b':
 150           make_backups = 1;
 151           break;
 152         case 'f':
 153           interactive = 0;
 154           override_mode = 1;
 155           break;
 156         case 'i':
 157           interactive = 1;
 158           override_mode = 0;
 159           break;
 160         case 'u':
 161           update = 1;
 162           break;
 163         case 'v':
 164           verbose = 1;
 165           break;
 166         case 'S':
 167           simple_backup_suffix = optarg;
 168           break;
 169         case 'V':
 170           version = optarg;
 171           break;
 172         default:
 173           usage (1);
 174         }
 175     }
 176
 177   if (show_version)
 178     {
 179       printf ("%s\n", version_string);
 180       exit (0);
 181     }
 182
 183   if (show_help)
 184     usage (0);
 185
 186   if (argc < optind + 2)
 187     usage (1);
 188
 189   if (make_backups)
 190     backup_type = get_version (version);
 191
 192   stdin_tty = isatty (0);
 193
 194   if (argc > optind + 2 && !isdir (argv[argc - 1]))
 195     error (1, 0, "when moving multiple files, last argument must be a directory");
 196
 197   /* Move each arg but the last onto the last. */
 198   for (; optind < argc - 1; ++optind)
 199     errors |= movefile (argv[optind], argv[argc - 1]);
 200
 201   exit (errors);
 202 }
 203
 204 /* If PATH is an existing directory, return nonzero, else 0.  */
 205
 206 static int
 207 is_real_dir (path)
 208      char *path;
 209 {
 210   struct stat stats;
 211
 212   return lstat (path, &stats) == 0 && S_ISDIR (stats.st_mode);
 213 }
 214
 215 /* Move file SOURCE onto DEST.  Handles the case when DEST is a directory.
 216    Return 0 if successful, 1 if an error occurred.  */
 217
 218 static int
 219 movefile (source, dest)
 220      char *source;
 221      char *dest;
 222 {
 223   strip_trailing_slashes (source);
 224
 225   if ((dest[strlen (dest) - 1] == '/' && !is_real_dir (source))
 226       || isdir (dest))
 227     {
 228       /* Target is a directory; build full target filename. */
 229       char *base;
 230       char *new_dest;
 231
 232       base = basename (source);
 233       new_dest = (char *) alloca (strlen (dest) + 1 + strlen (base) + 1);
 234       stpcpy (stpcpy (stpcpy (new_dest, dest), "/"), base);
 235       return do_move (source, new_dest);
 236     }
 237   else
 238     return do_move (source, dest);
 239 }
 240
 241 static struct stat dest_stats, source_stats;
 242
 243 /* Move SOURCE onto DEST.  Handles cross-filesystem moves.
 244    If DEST is a directory, SOURCE must be also.
 245    Return 0 if successful, 1 if an error occurred.  */
 246
 247 static int
 248 do_move (source, dest)
 249      char *source;
 250      char *dest;
 251 {
 252   char *dest_backup = NULL;
 253
 254   if (lstat (source, &source_stats) != 0)
 255     {
 256       error (0, errno, "%s", source);
 257       return 1;
 258     }
 259
 260   if (lstat (dest, &dest_stats) == 0)
 261     {
 262       if (source_stats.st_dev == dest_stats.st_dev
 263           && source_stats.st_ino == dest_stats.st_ino)
 264         {
 265           error (0, 0, "`%s' and `%s' are the same file", source, dest);
 266           return 1;
 267         }
 268
 269       if (S_ISDIR (dest_stats.st_mode))
 270         {
 271           error (0, 0, "%s: cannot overwrite directory", dest);
 272           return 1;
 273         }
 274
 275       if (!S_ISDIR (source_stats.st_mode) && update
 276           && source_stats.st_mtime <= dest_stats.st_mtime)
 277         return 0;
 278
 279       if (!override_mode && (interactive || stdin_tty)
 280           && eaccess_stat (&dest_stats, W_OK))
 281         {
 282           fprintf (stderr, "%s: replace `%s', overriding mode %04o? ",
 283                    program_name, dest,
 284                    (unsigned int) (dest_stats.st_mode & 07777));
 285           if (!yesno ())
 286             return 0;
 287         }
 288       else if (interactive)
 289         {
 290           fprintf (stderr, "%s: replace `%s'? ", program_name, dest);
 291           if (!yesno ())
 292             return 0;
 293         }
 294
 295       if (backup_type != none)
 296         {
 297           char *tmp_backup = find_backup_file_name (dest);
 298           if (tmp_backup == NULL)
 299             error (1, 0, "virtual memory exhausted");
 300           dest_backup = (char *) alloca (strlen (tmp_backup) + 1);
 301           strcpy (dest_backup, tmp_backup);
 302           free (tmp_backup);
 303           if (rename (dest, dest_backup))
 304             {
 305               if (errno != ENOENT)
 306                 {
 307                   error (0, errno, "cannot backup `%s'", dest);
 308                   return 1;
 309                 }
 310               else
 311                 dest_backup = NULL;
 312             }
 313         }
 314     }
 315   else if (errno != ENOENT)
 316     {
 317       error (0, errno, "%s", dest);
 318       return 1;
 319     }
 320
 321   if (verbose)
 322     printf ("%s -> %s\n", source, dest);
 323
 324   if (rename (source, dest) == 0)
 325     {
 326       return 0;
 327     }
 328
 329   if (errno != EXDEV)
 330     {
 331       error (0, errno, "cannot move `%s' to `%s'", source, dest);
 332       goto un_backup;
 333     }
 334
 335   /* rename failed on cross-filesystem link.  Copy the file instead. */
 336
 337   if (copy_reg (source, dest))
 338     goto un_backup;
 339
 340   if (unlink (source))
 341     {
 342       error (0, errno, "cannot remove `%s'", source);
 343       return 1;
 344     }
 345
 346   return 0;
 347
 348  un_backup:
 349   if (dest_backup)
 350     {
 351       if (rename (dest_backup, dest))
 352         error (0, errno, "cannot un-backup `%s'", dest);
 353     }
 354   return 1;
 355 }
 356
 357 /* Copy regular file SOURCE onto file DEST.
 358    Return 1 if an error occurred, 0 if successful. */
 359
 360 static int
 361 copy_reg (source, dest)
 362      char *source, *dest;
 363 {
 364   int ifd;
 365   int ofd;
 366   char buf[1024 * 8];
 367   int len;                      /* Number of bytes read into `buf'. */
 368
 369   if (!S_ISREG (source_stats.st_mode))
 370     {
 371       error (0, 0, "cannot move `%s' across filesystems: Not a regular file",
 372              source);
 373       return 1;
 374     }
 375
 376   if (unlink (dest) && errno != ENOENT)
 377     {
 378       error (0, errno, "cannot remove `%s'", dest);
 379       return 1;
 380     }
 381
 382   ifd = open (source, O_RDONLY, 0);
 383   if (ifd < 0)
 384     {
 385       error (0, errno, "%s", source);
 386       return 1;
 387     }
 388   ofd = open (dest, O_WRONLY | O_CREAT | O_TRUNC, 0600);
 389   if (ofd < 0)
 390     {
 391       error (0, errno, "%s", dest);
 392       close (ifd);
 393       return 1;
 394     }
 395
 396   while ((len = read (ifd, buf, sizeof (buf))) > 0)
 397     {
 398       int wrote = 0;
 399       char *bp = buf;
 400
 401       do
 402         {
 403           wrote = write (ofd, bp, len);
 404           if (wrote < 0)
 405             {
 406               error (0, errno, "%s", dest);
 407               close (ifd);
 408               close (ofd);
 409               unlink (dest);
 410               return 1;
 411             }
 412           bp += wrote;
 413           len -= wrote;
 414         } while (len > 0);
 415     }
 416   if (len < 0)
 417     {
 418       error (0, errno, "%s", source);
 419       close (ifd);
 420       close (ofd);
 421       unlink (dest);
 422       return 1;
 423     }
 424
 425   if (close (ifd) < 0)
 426     {
 427       error (0, errno, "%s", source);
 428       close (ofd);
 429       return 1;
 430     }
 431   if (close (ofd) < 0)
 432     {
 433       error (0, errno, "%s", dest);
 434       return 1;
 435     }
 436
 437   /* chown turns off set[ug]id bits for non-root,
 438      so do the chmod last.  */
 439
 440   /* Try to copy the old file's modtime and access time.  */
 441   {
 442     struct utimbuf tv;
 443
 444     tv.actime = source_stats.st_atime;
 445     tv.modtime = source_stats.st_mtime;
 446     if (utime (dest, &tv))
 447       {
 448         error (0, errno, "%s", dest);
 449         return 1;
 450       }
 451   }
 452
 453   /* Try to preserve ownership.  For non-root it might fail, but that's ok.
 454      But root probably wants to know, e.g. if NFS disallows it.  */
 455   if (chown (dest, source_stats.st_uid, source_stats.st_gid)
 456       && (errno != EPERM || myeuid == 0))
 457     {
 458       error (0, errno, "%s", dest);
 459       return 1;
 460     }
 461
 462   if (chmod (dest, source_stats.st_mode & 07777))
 463     {
 464       error (0, errno, "%s", dest);
 465       return 1;
 466     }
 467
 468   return 0;
 469 }
 470
 471 static void
 472 usage (status)
 473      int status;
 474 {
 475   fprintf (status == 0 ? stdout : stderr, "\
 476 Usage: %s [OPTION]... SOURCE DEST\n\
 477   or:  %s [OPTION]... SOURCE... DIRECTORY\n\
 478 \n",
 479            program_name, program_name);
 480
 481   if (status == 0)
 482     fprintf (stdout, "\
 483   -b, --backup                 make backup before removal\n\
 484   -f, --force                  remove existing destinations, never prompt\n\
 485   -i, --interactive            prompt before overwrite\n\
 486   -u, --update                 move only older or brand new files\n\
 487   -v, --verbose                explain what is being done\n\
 488   -S, --suffix SUFFIX          override the usual backup suffix\n\
 489   -V, --version-control WORD   override the usual version control\n\
 490       --help                   display this help and exit\n\
 491       --version                output version information and exit\n\
 492 \n\
 493 The backup suffix is ~, unless set with SIMPLE_BACKUP_SUFFIX.  The\n\
 494 version control may be set with VERSION_CONTROL, values are:\n\
 495 \n\
 496   t, numbered     make numbered backups\n\
 497   nil, existing   numbered if numbered backups exist, simple otherwise\n\
 498   never, simple   always make simple backups  \n");
 499
 500   else
 501     fprintf (stderr, "Try `%s --help' for more information.\n",
 502              program_name);
 503
 504   exit (status);
 505 }