fileio.c 170 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* File IO for GNU Emacs.
2 3
   Copyright (C) 1985, 1986, 1987, 1988, 1993, 1994, 1995, 1996,
                 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
Glenn Morris's avatar
Glenn Morris committed
4
                 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
5 6 7

This file is part of GNU Emacs.

8
GNU Emacs is free software: you can redistribute it and/or modify
Jim Blandy's avatar
Jim Blandy committed
9
it under the terms of the GNU General Public License as published by
10 11
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Jim Blandy's avatar
Jim Blandy committed
12 13 14 15 16 17 18

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
19
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
Jim Blandy's avatar
Jim Blandy committed
20

21
#include <config.h>
22
#include <limits.h>
Jim Blandy's avatar
Jim Blandy committed
23

24
#ifdef HAVE_FCNTL_H
25 26 27
#include <fcntl.h>
#endif

28
#include <stdio.h>
Jim Blandy's avatar
Jim Blandy committed
29 30
#include <sys/types.h>
#include <sys/stat.h>
Jim Blandy's avatar
Jim Blandy committed
31

32 33 34 35
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

36 37 38 39
#if !defined (S_ISLNK) && defined (S_IFLNK)
#  define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
#endif

40 41 42 43
#if !defined (S_ISFIFO) && defined (S_IFIFO)
#  define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
#endif

44 45 46 47
#if !defined (S_ISREG) && defined (S_IFREG)
#  define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
#endif

48
#ifdef HAVE_PWD_H
Jim Blandy's avatar
Jim Blandy committed
49
#include <pwd.h>
Jim Blandy's avatar
Jim Blandy committed
50 51
#endif

Jim Blandy's avatar
Jim Blandy committed
52 53 54
#include <ctype.h>
#include <errno.h>

Jim Blandy's avatar
Jim Blandy committed
55
#ifndef vax11c
56
#ifndef USE_CRT_DLL
Jim Blandy's avatar
Jim Blandy committed
57 58
extern int errno;
#endif
59
#endif
Jim Blandy's avatar
Jim Blandy committed
60 61

#include "lisp.h"
62
#include "intervals.h"
Jim Blandy's avatar
Jim Blandy committed
63
#include "buffer.h"
64
#include "character.h"
Karl Heuer's avatar
Karl Heuer committed
65
#include "coding.h"
Jim Blandy's avatar
Jim Blandy committed
66
#include "window.h"
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
67
#include "blockinput.h"
Karoly Lorentey's avatar
Karoly Lorentey committed
68 69
#include "frame.h"
#include "dispextern.h"
Jim Blandy's avatar
Jim Blandy committed
70

71 72 73 74 75 76 77
#ifdef WINDOWSNT
#define NOMINMAX 1
#include <windows.h>
#include <stdlib.h>
#include <fcntl.h>
#endif /* not WINDOWSNT */

Eli Zaretskii's avatar
Eli Zaretskii committed
78 79 80 81 82 83 84 85 86
#ifdef MSDOS
#include "msdos.h"
#include <sys/param.h>
#if __DJGPP__ >= 2
#include <fcntl.h>
#include <string.h>
#endif
#endif

87 88 89 90 91 92 93 94 95 96 97 98 99
#ifdef DOS_NT
#define CORRECT_DIR_SEPS(s) \
  do { if ('/' == DIRECTORY_SEP) dostounix_filename (s); \
       else unixtodos_filename (s); \
  } while (0)
/* On Windows, drive letters must be alphabetic - on DOS, the Netware
   redirector allows the six letters between 'Z' and 'a' as well. */
#ifdef MSDOS
#define IS_DRIVE(x) ((x) >= 'A' && (x) <= 'z')
#endif
#ifdef WINDOWSNT
#define IS_DRIVE(x) isalpha (x)
#endif
100 101 102 103
/* Need to lower-case the drive letter, or else expanded
   filenames will sometimes compare inequal, because
   `expand-file-name' doesn't always down-case the drive letter.  */
#define DRIVE_LETTER(x) (tolower (x))
104 105
#endif

Jim Blandy's avatar
Jim Blandy committed
106
#include "systime.h"
Jim Blandy's avatar
Jim Blandy committed
107 108 109

#ifdef HPUX
#include <netio.h>
110
#endif
Jim Blandy's avatar
Jim Blandy committed
111

112 113
#include "commands.h"
extern int use_dialog_box;
Kenichi Handa's avatar
Kenichi Handa committed
114
extern int use_file_dialog;
115

Jim Blandy's avatar
Jim Blandy committed
116 117 118 119
#ifndef O_WRONLY
#define O_WRONLY 1
#endif

Richard M. Stallman's avatar
Richard M. Stallman committed
120 121 122 123
#ifndef O_RDONLY
#define O_RDONLY 0
#endif

124 125 126 127
#ifndef S_ISLNK
#  define lstat stat
#endif

128 129 130 131
#ifndef FILE_SYSTEM_CASE
#define FILE_SYSTEM_CASE(filename)  (filename)
#endif

Jim Blandy's avatar
Jim Blandy committed
132 133 134 135 136 137 138
/* Nonzero during writing of auto-save files */
int auto_saving;

/* Set by auto_save_1 to mode of original file so Fwrite_region will create
   a new file with the same mode as the original */
int auto_save_mode_bits;

139 140 141
/* Set by auto_save_1 if an error occurred during the last auto-save. */
int auto_save_error_occurred;

142 143 144 145 146 147 148
/* The symbol bound to coding-system-for-read when
   insert-file-contents is called for recovering a file.  This is not
   an actual coding system name, but just an indicator to tell
   insert-file-contents to use `emacs-mule' with a special flag for
   auto saving and recovering a file.  */
Lisp_Object Qauto_save_coding;

149 150 151
/* Coding system for file names, or nil if none.  */
Lisp_Object Vfile_name_coding_system;

152 153 154 155
/* Coding system for file names used only when
   Vfile_name_coding_system is nil.  */
Lisp_Object Vdefault_file_name_coding_system;

156
/* Alist of elements (REGEXP . HANDLER) for file names
157 158 159
   whose I/O is done with a special handler.  */
Lisp_Object Vfile_name_handler_alist;

160 161 162 163
/* Property name of a file name handler,
   which gives a list of operations it handles..  */
Lisp_Object Qoperations;

164 165 166
/* Lisp functions for translating file formats */
Lisp_Object Qformat_decode, Qformat_annotate_function;

167
/* Function to be called to decide a coding system of a reading file.  */
168
Lisp_Object Vset_auto_coding_function;
169

170 171 172
/* Functions to be called to process text properties in inserted file.  */
Lisp_Object Vafter_insert_file_functions;

173
/* Lisp function for setting buffer-file-coding-system and the
174
   multibyteness of the current buffer after inserting a file.  */
175
Lisp_Object Qafter_insert_file_set_coding;
176

177 178
/* Functions to be called to create text property annotations for file.  */
Lisp_Object Vwrite_region_annotate_functions;
179
Lisp_Object Qwrite_region_annotate_functions;
180

181 182 183 184
/* During build_annotations, each time an annotation function is called,
   this holds the annotations made by the previous functions.  */
Lisp_Object Vwrite_region_annotations_so_far;

185 186 187
/* File name in which we write a list of all our auto save files.  */
Lisp_Object Vauto_save_list_file_name;

188 189 190
/* Whether or not files are auto-saved into themselves.  */
Lisp_Object Vauto_save_visited_file_name;

191 192 193 194
/* On NT, specifies the directory separator character, used (eg.) when
   expanding file names.  This can be bound to / or \. */
Lisp_Object Vdirectory_sep_char;

195 196 197 198 199
#ifdef HAVE_FSYNC
/* Nonzero means skip the call to fsync in Fwrite-region.  */
int write_region_inhibit_fsync;
#endif

200 201 202 203 204 205 206
/* Non-zero means call move-file-to-trash in Fdelete_file or
   Fdelete_directory.  */
int delete_by_moving_to_trash;

/* Lisp function for moving files to trash.  */
Lisp_Object Qmove_file_to_trash;

207 208
extern Lisp_Object Vuser_login_name;

209 210 211 212
#ifdef WINDOWSNT
extern Lisp_Object Vw32_get_true_file_attributes;
#endif

213 214
extern int minibuf_level;

215 216
extern int minibuffer_auto_raise;

217 218
extern int history_delete_duplicates;

219 220 221 222 223 224 225
/* These variables describe handlers that have "already" had a chance
   to handle the current operation.

   Vinhibit_file_name_handlers is a list of file name handlers.
   Vinhibit_file_name_operation is the operation being handled.
   If we try to handle that operation, we ignore those handlers.  */

226
static Lisp_Object Vinhibit_file_name_handlers;
227
static Lisp_Object Vinhibit_file_name_operation;
228

229
Lisp_Object Qfile_error, Qfile_already_exists, Qfile_date_error;
Richard M. Stallman's avatar
Richard M. Stallman committed
230
Lisp_Object Qexcl;
231 232
Lisp_Object Qfile_name_history;

233 234
Lisp_Object Qcar_less_than_car;

235
static int a_write P_ ((int, Lisp_Object, int, int,
236
			Lisp_Object *, struct coding_system *));
237 238
static int e_write P_ ((int, Lisp_Object, int, int, struct coding_system *));

239

240
void
Jim Blandy's avatar
Jim Blandy committed
241
report_file_error (string, data)
242
     const char *string;
Jim Blandy's avatar
Jim Blandy committed
243 244 245
     Lisp_Object data;
{
  Lisp_Object errstring;
Richard M. Stallman's avatar
Richard M. Stallman committed
246
  int errorno = errno;
247
  char *str;
Jim Blandy's avatar
Jim Blandy committed
248

249
  synchronize_system_messages_locale ();
250 251 252
  str = strerror (errorno);
  errstring = code_convert_string_norecord (make_unibyte_string (str,
								 strlen (str)),
253 254
					    Vlocale_coding_system, 0);

Jim Blandy's avatar
Jim Blandy committed
255
  while (1)
Richard M. Stallman's avatar
Richard M. Stallman committed
256 257 258
    switch (errorno)
      {
      case EEXIST:
259
	xsignal (Qfile_already_exists, Fcons (errstring, data));
Richard M. Stallman's avatar
Richard M. Stallman committed
260 261 262 263
	break;
      default:
	/* System error messages are capitalized.  Downcase the initial
	   unless it is followed by a slash.  */
264
	if (SREF (errstring, 1) != '/')
265
	  SSET (errstring, 0, DOWNCASE (SREF (errstring, 0)));
Richard M. Stallman's avatar
Richard M. Stallman committed
266

267
	xsignal (Qfile_error,
Richard M. Stallman's avatar
Richard M. Stallman committed
268 269
		 Fcons (build_string (string), Fcons (errstring, data)));
      }
Jim Blandy's avatar
Jim Blandy committed
270
}
271

272
Lisp_Object
273 274 275
close_file_unwind (fd)
     Lisp_Object fd;
{
276
  emacs_close (XFASTINT (fd));
277
  return Qnil;
278
}
279 280 281

/* Restore point, having saved it as a marker.  */

282
static Lisp_Object
283
restore_point_unwind (location)
284
     Lisp_Object location;
285
{
286
  Fgoto_char (location);
287
  Fset_marker (location, Qnil, Qnil);
288
  return Qnil;
289
}
290

Jim Blandy's avatar
Jim Blandy committed
291

292
Lisp_Object Qexpand_file_name;
293
Lisp_Object Qsubstitute_in_file_name;
294 295 296
Lisp_Object Qdirectory_file_name;
Lisp_Object Qfile_name_directory;
Lisp_Object Qfile_name_nondirectory;
297
Lisp_Object Qunhandled_file_name_directory;
298
Lisp_Object Qfile_name_as_directory;
299
Lisp_Object Qcopy_file;
300
Lisp_Object Qmake_directory_internal;
301
Lisp_Object Qmake_directory;
302 303 304 305 306 307 308 309 310
Lisp_Object Qdelete_directory;
Lisp_Object Qdelete_file;
Lisp_Object Qrename_file;
Lisp_Object Qadd_name_to_file;
Lisp_Object Qmake_symbolic_link;
Lisp_Object Qfile_exists_p;
Lisp_Object Qfile_executable_p;
Lisp_Object Qfile_readable_p;
Lisp_Object Qfile_writable_p;
311 312
Lisp_Object Qfile_symlink_p;
Lisp_Object Qaccess_file;
313
Lisp_Object Qfile_directory_p;
314
Lisp_Object Qfile_regular_p;
315 316 317
Lisp_Object Qfile_accessible_directory_p;
Lisp_Object Qfile_modes;
Lisp_Object Qset_file_modes;
318
Lisp_Object Qset_file_times;
319 320 321 322
Lisp_Object Qfile_newer_than_file_p;
Lisp_Object Qinsert_file_contents;
Lisp_Object Qwrite_region;
Lisp_Object Qverify_visited_file_modtime;
323
Lisp_Object Qset_visited_file_modtime;
324

325
DEFUN ("find-file-name-handler", Ffind_file_name_handler, Sfind_file_name_handler, 2, 2, 0,
326 327 328 329 330 331 332 333 334 335 336
       doc: /* Return FILENAME's handler function for OPERATION, if it has one.
Otherwise, return nil.
A file name is handled if one of the regular expressions in
`file-name-handler-alist' matches it.

If OPERATION equals `inhibit-file-name-operation', then we ignore
any handlers that are members of `inhibit-file-name-handlers',
but we still do run any other handlers.  This lets handlers
use the standard functions without calling themselves recursively.  */)
     (filename, operation)
     Lisp_Object filename, operation;
337
{
338
  /* This function must not munge the match data.  */
339
  Lisp_Object chain, inhibited_handlers, result;
340
  int pos = -1;
341

342
  result = Qnil;
343
  CHECK_STRING (filename);
344

345 346 347 348
  if (EQ (operation, Vinhibit_file_name_operation))
    inhibited_handlers = Vinhibit_file_name_handlers;
  else
    inhibited_handlers = Qnil;
349

350
  for (chain = Vfile_name_handler_alist; CONSP (chain);
351
       chain = XCDR (chain))
352 353
    {
      Lisp_Object elt;
354
      elt = XCAR (chain);
355
      if (CONSP (elt))
356
	{
357
	  Lisp_Object string = XCAR (elt);
358
	  int match_pos;
359
	  Lisp_Object handler = XCDR (elt);
360 361 362 363
	  Lisp_Object operations = Qnil;

	  if (SYMBOLP (handler))
	    operations = Fget (handler, Qoperations);
364

365
	  if (STRINGP (string)
366 367
	      && (match_pos = fast_string_match (string, filename)) > pos
	      && (NILP (operations) || ! NILP (Fmemq (operation, operations))))
368
	    {
369
	      Lisp_Object tem;
370

371
	      handler = XCDR (elt);
372 373
	      tem = Fmemq (handler, inhibited_handlers);
	      if (NILP (tem))
374 375 376 377
		{
		  result = handler;
		  pos = match_pos;
		}
378
	    }
379
	}
380 381

      QUIT;
382
    }
383
  return result;
384 385
}

Jim Blandy's avatar
Jim Blandy committed
386
DEFUN ("file-name-directory", Ffile_name_directory, Sfile_name_directory,
387 388 389
       1, 1, 0,
       doc: /* Return the directory component in file name FILENAME.
Return nil if FILENAME does not include a directory.
390
Otherwise return a directory name.
Dan Nicolaescu's avatar
Dan Nicolaescu committed
391
Given a Unix syntax file name, returns a string ending in slash.  */)
392
     (filename)
393
     Lisp_Object filename;
Jim Blandy's avatar
Jim Blandy committed
394
{
395
#ifndef DOS_NT
396
  register const unsigned char *beg;
397 398 399
#else
  register unsigned char *beg;
#endif
400
  register const unsigned char *p;
401
  Lisp_Object handler;
Jim Blandy's avatar
Jim Blandy committed
402

403
  CHECK_STRING (filename);
Jim Blandy's avatar
Jim Blandy committed
404

405 406
  /* If the file name has special constructs in it,
     call the corresponding file handler.  */
407
  handler = Ffind_file_name_handler (filename, Qfile_name_directory);
408
  if (!NILP (handler))
409
    return call2 (handler, Qfile_name_directory, filename);
410

411
  filename = FILE_SYSTEM_CASE (filename);
412
  beg = SDATA (filename);
413 414 415
#ifdef DOS_NT
  beg = strcpy (alloca (strlen (beg) + 1), beg);
#endif
416
  p = beg + SBYTES (filename);
Jim Blandy's avatar
Jim Blandy committed
417

418 419
  while (p != beg && !IS_DIRECTORY_SEP (p[-1])
#ifdef DOS_NT
420 421 422 423 424
	 /* only recognise drive specifier at the beginning */
	 && !(p[-1] == ':'
	      /* handle the "/:d:foo" and "/:foo" cases correctly  */
	      && ((p == beg + 2 && !IS_DIRECTORY_SEP (*beg))
		  || (p == beg + 4 && IS_DIRECTORY_SEP (*beg))))
425
#endif
Jim Blandy's avatar
Jim Blandy committed
426 427 428 429
	 ) p--;

  if (p == beg)
    return Qnil;
430
#ifdef DOS_NT
431
  /* Expansion of "c:" to drive and default directory.  */
432
  if (p[-1] == ':')
433 434
    {
      /* MAXPATHLEN+1 is guaranteed to be enough space for getdefdir.  */
435
      unsigned char *res = alloca (MAXPATHLEN + 1);
436 437 438 439 440 441 442 443 444 445
      unsigned char *r = res;

      if (p == beg + 4 && IS_DIRECTORY_SEP (*beg) && beg[1] == ':')
	{
	  strncpy (res, beg, 2);
	  beg += 2;
	  r += 2;
	}

      if (getdefdir (toupper (*beg) - 'A' + 1, r))
446
	{
447
	  if (!IS_DIRECTORY_SEP (res[strlen (res) - 1]))
448 449 450 451 452
	    strcat (res, "/");
	  beg = res;
	  p = beg + strlen (beg);
	}
    }
453
  CORRECT_DIR_SEPS (beg);
454
#endif /* DOS_NT */
455

456
  return make_specified_string (beg, -1, p - beg, STRING_MULTIBYTE (filename));
Jim Blandy's avatar
Jim Blandy committed
457 458
}

459 460
DEFUN ("file-name-nondirectory", Ffile_name_nondirectory,
       Sfile_name_nondirectory, 1, 1, 0,
461 462 463 464 465
       doc: /* Return file name FILENAME sans its directory.
For example, in a Unix-syntax file name,
this is everything after the last slash,
or the entire name if it contains no slash.  */)
     (filename)
466
     Lisp_Object filename;
Jim Blandy's avatar
Jim Blandy committed
467
{
468
  register const unsigned char *beg, *p, *end;
469
  Lisp_Object handler;
Jim Blandy's avatar
Jim Blandy committed
470

471
  CHECK_STRING (filename);
Jim Blandy's avatar
Jim Blandy committed
472

473 474
  /* If the file name has special constructs in it,
     call the corresponding file handler.  */
475
  handler = Ffind_file_name_handler (filename, Qfile_name_nondirectory);
476
  if (!NILP (handler))
477
    return call2 (handler, Qfile_name_nondirectory, filename);
478

479 480
  beg = SDATA (filename);
  end = p = beg + SBYTES (filename);
Jim Blandy's avatar
Jim Blandy committed
481

482 483 484
  while (p != beg && !IS_DIRECTORY_SEP (p[-1])
#ifdef DOS_NT
	 /* only recognise drive specifier at beginning */
485 486 487
	 && !(p[-1] == ':'
	      /* handle the "/:d:foo" case correctly  */
	      && (p == beg + 2 || (p == beg + 4 && IS_DIRECTORY_SEP (*beg))))
488
#endif
489 490
	 )
    p--;
Jim Blandy's avatar
Jim Blandy committed
491

492
  return make_specified_string (p, -1, end - p, STRING_MULTIBYTE (filename));
Jim Blandy's avatar
Jim Blandy committed
493
}
494

495 496
DEFUN ("unhandled-file-name-directory", Funhandled_file_name_directory,
       Sunhandled_file_name_directory, 1, 1, 0,
497 498 499 500 501
       doc: /* Return a directly usable directory name somehow associated with FILENAME.
A `directly usable' directory name is one that may be used without the
intervention of any file handler.
If FILENAME is a directly usable file itself, return
\(file-name-directory FILENAME).
Stefan Monnier's avatar
Stefan Monnier committed
502 503
If FILENAME refers to a file which is not accessible from a local process,
then this should return nil.
504 505 506 507
The `call-process' and `start-process' functions use this function to
get a current directory to run processes in.  */)
     (filename)
     Lisp_Object filename;
508 509 510 511 512
{
  Lisp_Object handler;

  /* If the file name has special constructs in it,
     call the corresponding file handler.  */
513
  handler = Ffind_file_name_handler (filename, Qunhandled_file_name_directory);
514 515 516 517 518 519
  if (!NILP (handler))
    return call2 (handler, Qunhandled_file_name_directory, filename);

  return Ffile_name_directory (filename);
}

Jim Blandy's avatar
Jim Blandy committed
520 521 522 523 524 525 526 527 528

char *
file_name_as_directory (out, in)
     char *out, *in;
{
  int size = strlen (in) - 1;

  strcpy (out, in);

529 530
  if (size < 0)
    {
531 532 533
      out[0] = '.';
      out[1] = '/';
      out[2] = 0;
534 535 536
      return out;
    }

Jim Blandy's avatar
Jim Blandy committed
537
  /* For Unix syntax, Append a slash if necessary */
538
  if (!IS_DIRECTORY_SEP (out[size]))
539
    {
540 541
      /* Cannot use DIRECTORY_SEP, which could have any value */
      out[size + 1] = '/';
542 543
      out[size + 2] = '\0';
    }
544 545 546
#ifdef DOS_NT
  CORRECT_DIR_SEPS (out);
#endif
Jim Blandy's avatar
Jim Blandy committed
547 548 549 550 551
  return out;
}

DEFUN ("file-name-as-directory", Ffile_name_as_directory,
       Sfile_name_as_directory, 1, 1, 0,
552
       doc: /* Return a string representing the file name FILE interpreted as a directory.
553 554 555 556
This operation exists because a directory is also a file, but its name as
a directory is different from its name as a file.
The result can be used as the value of `default-directory'
or passed as second argument to `expand-file-name'.
Dan Nicolaescu's avatar
Dan Nicolaescu committed
557
For a Unix-syntax file name, just appends a slash.  */)
558
     (file)
Jim Blandy's avatar
Jim Blandy committed
559 560 561
     Lisp_Object file;
{
  char *buf;
562
  Lisp_Object handler;
Jim Blandy's avatar
Jim Blandy committed
563

564
  CHECK_STRING (file);
Jim Blandy's avatar
Jim Blandy committed
565
  if (NILP (file))
Jim Blandy's avatar
Jim Blandy committed
566
    return Qnil;
567 568 569

  /* If the file name has special constructs in it,
     call the corresponding file handler.  */
570
  handler = Ffind_file_name_handler (file, Qfile_name_as_directory);
571 572 573
  if (!NILP (handler))
    return call2 (handler, Qfile_name_as_directory, file);

574
  buf = (char *) alloca (SBYTES (file) + 10);
575 576 577
  file_name_as_directory (buf, SDATA (file));
  return make_specified_string (buf, -1, strlen (buf),
				STRING_MULTIBYTE (file));
Jim Blandy's avatar
Jim Blandy committed
578 579 580 581
}

/*
 * Convert from directory name to filename.
582
 * On UNIX, it's simple: just make sure there isn't a terminating /
Jim Blandy's avatar
Jim Blandy committed
583 584 585 586

 * Value is nonzero if the string output is different from the input.
 */

Andreas Schwab's avatar
Andreas Schwab committed
587
int
Jim Blandy's avatar
Jim Blandy committed
588 589 590 591 592 593
directory_file_name (src, dst)
     char *src, *dst;
{
  long slen;

  slen = strlen (src);
Dan Nicolaescu's avatar
Dan Nicolaescu committed
594

Jim Blandy's avatar
Jim Blandy committed
595 596 597
  /* Process as Unix format: just remove any final slash.
     But leave "/" unchanged; do not change it to "".  */
  strcpy (dst, src);
598
  if (slen > 1
599
      && IS_DIRECTORY_SEP (dst[slen - 1])
600 601 602 603
#ifdef DOS_NT
      && !IS_ANY_SEP (dst[slen - 2])
#endif
      )
Jim Blandy's avatar
Jim Blandy committed
604
    dst[slen - 1] = 0;
605 606
#ifdef DOS_NT
  CORRECT_DIR_SEPS (dst);
607
#endif
Jim Blandy's avatar
Jim Blandy committed
608 609 610 611
  return 1;
}

DEFUN ("directory-file-name", Fdirectory_file_name, Sdirectory_file_name,
612 613 614 615 616
       1, 1, 0,
       doc: /* Returns the file name of the directory named DIRECTORY.
This is the name of the file that holds the data for the directory DIRECTORY.
This operation exists because a directory is also a file, but its name as
a directory is different from its name as a file.
Dan Nicolaescu's avatar
Dan Nicolaescu committed
617
In Unix-syntax, this function just removes the final slash.  */)
618
     (directory)
Jim Blandy's avatar
Jim Blandy committed
619 620 621
     Lisp_Object directory;
{
  char *buf;
622
  Lisp_Object handler;
Jim Blandy's avatar
Jim Blandy committed
623

624
  CHECK_STRING (directory);
Jim Blandy's avatar
Jim Blandy committed
625

Jim Blandy's avatar
Jim Blandy committed
626
  if (NILP (directory))
Jim Blandy's avatar
Jim Blandy committed
627
    return Qnil;
628 629 630

  /* If the file name has special constructs in it,
     call the corresponding file handler.  */
631
  handler = Ffind_file_name_handler (directory, Qdirectory_file_name);
632 633 634
  if (!NILP (handler))
    return call2 (handler, Qdirectory_file_name, directory);

635 636
  buf = (char *) alloca (SBYTES (directory) + 20);
  directory_file_name (SDATA (directory), buf);
637 638
  return make_specified_string (buf, -1, strlen (buf),
				STRING_MULTIBYTE (directory));
Jim Blandy's avatar
Jim Blandy committed
639 640
}

641 642 643 644 645 646 647 648 649 650 651
static char make_temp_name_tbl[64] =
{
  'A','B','C','D','E','F','G','H',
  'I','J','K','L','M','N','O','P',
  'Q','R','S','T','U','V','W','X',
  'Y','Z','a','b','c','d','e','f',
  'g','h','i','j','k','l','m','n',
  'o','p','q','r','s','t','u','v',
  'w','x','y','z','0','1','2','3',
  '4','5','6','7','8','9','-','_'
};
652

653 654
static unsigned make_temp_name_count, make_temp_name_count_initialized_p;

655
/* Value is a temporary file name starting with PREFIX, a string.
656

657 658 659 660 661
   The Emacs process number forms part of the result, so there is
   no danger of generating a name being used by another process.
   In addition, this function makes an attempt to choose a name
   which has no existing file.  To make this work, PREFIX should be
   an absolute file name.
662

663 664 665 666 667 668 669 670 671 672
   BASE64_P non-zero means add the pid as 3 characters in base64
   encoding.  In this case, 6 characters will be added to PREFIX to
   form the file name.  Otherwise, if Emacs is running on a system
   with long file names, add the pid as a decimal number.

   This function signals an error if no unique file name could be
   generated.  */

Lisp_Object
make_temp_name (prefix, base64_p)
Jim Blandy's avatar
Jim Blandy committed
673
     Lisp_Object prefix;
674
     int base64_p;
Jim Blandy's avatar
Jim Blandy committed
675 676
{
  Lisp_Object val;
677
  int len, clen;
678 679 680 681
  int pid;
  unsigned char *p, *data;
  char pidbuf[20];
  int pidlen;
682

683
  CHECK_STRING (prefix);
684 685 686 687 688 689 690 691

  /* VAL is created by adding 6 characters to PREFIX.  The first
     three are the PID of this process, in base 64, and the second
     three are incremented if the file already exists.  This ensures
     262144 unique file names per PID per PREFIX.  */

  pid = (int) getpid ();

692 693 694 695 696 697 698 699 700
  if (base64_p)
    {
      pidbuf[0] = make_temp_name_tbl[pid & 63], pid >>= 6;
      pidbuf[1] = make_temp_name_tbl[pid & 63], pid >>= 6;
      pidbuf[2] = make_temp_name_tbl[pid & 63], pid >>= 6;
      pidlen = 3;
    }
  else
    {
701
#ifdef HAVE_LONG_FILE_NAMES
702 703
      sprintf (pidbuf, "%d", pid);
      pidlen = strlen (pidbuf);
704
#else
705 706 707 708
      pidbuf[0] = make_temp_name_tbl[pid & 63], pid >>= 6;
      pidbuf[1] = make_temp_name_tbl[pid & 63], pid >>= 6;
      pidbuf[2] = make_temp_name_tbl[pid & 63], pid >>= 6;
      pidlen = 3;
709
#endif
710
    }
711

712 713 714 715
  len = SBYTES (prefix); clen = SCHARS (prefix);
  val = make_uninit_multibyte_string (clen + 3 + pidlen, len + 3 + pidlen);
  if (!STRING_MULTIBYTE (prefix))
    STRING_SET_UNIBYTE (val);
716 717
  data = SDATA (val);
  bcopy(SDATA (prefix), data, len);
718 719 720 721 722 723 724 725
  p = data + len;

  bcopy (pidbuf, p, pidlen);
  p += pidlen;

  /* Here we try to minimize useless stat'ing when this function is
     invoked many times successively with the same PREFIX.  We achieve
     this by initializing count to a random value, and incrementing it
Richard M. Stallman's avatar
Richard M. Stallman committed
726 727 728 729 730 731
     afterwards.

     We don't want make-temp-name to be called while dumping,
     because then make_temp_name_count_initialized_p would get set
     and then make_temp_name_count would not be set when Emacs starts.  */

732 733 734 735 736 737 738 739 740
  if (!make_temp_name_count_initialized_p)
    {
      make_temp_name_count = (unsigned) time (NULL);
      make_temp_name_count_initialized_p = 1;
    }

  while (1)
    {
      struct stat ignored;
741
      unsigned num = make_temp_name_count;
742 743 744 745 746

      p[0] = make_temp_name_tbl[num & 63], num >>= 6;
      p[1] = make_temp_name_tbl[num & 63], num >>= 6;
      p[2] = make_temp_name_tbl[num & 63], num >>= 6;

747 748 749 750 751
      /* Poor man's congruential RN generator.  Replace with
         ++make_temp_name_count for debugging.  */
      make_temp_name_count += 25229;
      make_temp_name_count %= 225307;

752 753 754 755 756 757 758 759 760 761
      if (stat (data, &ignored) < 0)
	{
	  /* We want to return only if errno is ENOENT.  */
	  if (errno == ENOENT)
	    return val;
	  else
	    /* The error here is dubious, but there is little else we
	       can do.  The alternatives are to return nil, which is
	       as bad as (and in many cases worse than) throwing the
	       error, or to ignore the error, which will likely result
762 763 764
	       in looping through 225307 stat's, which is not only
	       dog-slow, but also useless since it will fallback to
	       the errow below, anyway.  */
765
	    report_file_error ("Cannot create temporary name for prefix",
766 767 768 769 770 771
			       Fcons (prefix, Qnil));
	  /* not reached */
	}
    }

  error ("Cannot create temporary name for prefix `%s'",
772
	 SDATA (prefix));
773
  return Qnil;
Jim Blandy's avatar
Jim Blandy committed
774
}
775

776 777

DEFUN ("make-temp-name", Fmake_temp_name, Smake_temp_name, 1, 1, 0,
778 779 780 781 782 783 784 785 786 787
       doc: /* Generate temporary file name (string) starting with PREFIX (a string).
The Emacs process number forms part of the result,
so there is no danger of generating a name being used by another process.

In addition, this function makes an attempt to choose a name
which has no existing file.  To make this work,
PREFIX should be an absolute file name.

There is a race condition between calling `make-temp-name' and creating the
file which opens all kinds of security holes.  For that reason, you should
788 789 790 791 792
probably use `make-temp-file' instead, except in three circumstances:

* If you are creating the file in the user's home directory.
* If you are creating a directory rather than an ordinary file.
* If you are taking special precautions as `make-temp-file' does.  */)
793
     (prefix)
794 795 796 797 798 799
     Lisp_Object prefix;
{
  return make_temp_name (prefix, 0);
}


Jim Blandy's avatar
Jim Blandy committed
800 801

DEFUN ("expand-file-name", Fexpand_file_name, Sexpand_file_name, 1, 2, 0,
802 803
       doc: /* Convert filename NAME to absolute, and canonicalize it.
Second arg DEFAULT-DIRECTORY is directory to start with if NAME is relative
804
\(does not start with slash or tilde); if DEFAULT-DIRECTORY is nil or missing,
805
the current buffer's value of `default-directory' is used.
806 807 808 809 810 811 812 813
File name components that are `.' are removed, and
so are file name components followed by `..', along with the `..' itself;
note that these simplifications are done without checking the resulting
file names in the file system.
An initial `~/' expands to your home directory.
An initial `~USER/' expands to USER's home directory.
See also the function `substitute-in-file-name'.  */)
     (name, default_directory)
814
     Lisp_Object name, default_directory;
Jim Blandy's avatar
Jim Blandy committed
815
{
816 817 818
  /* These point to SDATA and need to be careful with string-relocation
     during GC (via DECODE_FILE).  */
  unsigned char *nm, *newdir;
819
  int nm_in_name;
820 821
  /* This should only point to alloca'd data.  */
  unsigned char *target;
822

Jim Blandy's avatar
Jim Blandy committed
823 824
  int tlen;
  struct passwd *pw;
825
#ifdef DOS_NT
826
  int drive = 0;
827
  int collapse_newdir = 1;
828
  int is_escaped = 0;
829
#endif /* DOS_NT */
830
  int length;
831
  Lisp_Object handler, result;
832
  int multibyte;
833
  Lisp_Object hdir;
834

835
  CHECK_STRING (name);
Jim Blandy's avatar
Jim Blandy committed
836

837 838
  /* If the file name has special constructs in it,
     call the corresponding file handler.  */
839
  handler = Ffind_file_name_handler (name, Qexpand_file_name);
840
  if (!NILP (handler))
841
    return call3 (handler, Qexpand_file_name, name, default_directory);
842

843 844 845
  /* Use the buffer's default-directory if DEFAULT_DIRECTORY is omitted.  */
  if (NILP (default_directory))
    default_directory = current_buffer->directory;
846
  if (! STRINGP (default_directory))
847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863
    {
#ifdef DOS_NT
      /* "/" is not considered a root directory on DOS_NT, so using "/"
	 here causes an infinite recursion in, e.g., the following:

            (let (default-directory)
	      (expand-file-name "a"))

	 To avoid this, we set default_directory to the root of the
	 current drive.  */
      extern char *emacs_root_dir (void);

      default_directory = build_string (emacs_root_dir ());
#else
      default_directory = build_string ("/");
#endif
    }
864

865
  if (!NILP (default_directory))
866
    {
867
      handler = Ffind_file_name_handler (default_directory, Qexpand_file_name);
868
      if (!NILP (handler))
869
	return call3 (handler, Qexpand_file_name, name, default_directory);
870
    }
871

872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888
  {
    unsigned char *o = SDATA (default_directory);

    /* Make sure DEFAULT_DIRECTORY is properly expanded.
       It would be better to do this down below where we actually use
       default_directory.  Unfortunately, calling Fexpand_file_name recursively
       could invoke GC, and the strings might be relocated.  This would
       be annoying because we have pointers into strings lying around
       that would need adjusting, and people would add new pointers to
       the code and forget to adjust them, resulting in intermittent bugs.
       Putting this call here avoids all that crud.

       The EQ test avoids infinite recursion.  */
    if (! NILP (default_directory) && !EQ (default_directory, name)
	/* Save time in some common cases - as long as default_directory
	   is not relative, it can be canonicalized with name below (if it
	   is needed at all) without requiring it to be expanded now.  */
889
#ifdef DOS_NT
890 891 892
	/* Detect MSDOS file names with drive specifiers.  */
	&& ! (IS_DRIVE (o[0]) && IS_DEVICE_SEP (o[1])
	      && IS_DIRECTORY_SEP (o[2]))
893
#ifdef WINDOWSNT
894 895
	/* Detect Windows file names in UNC format.  */
	&& ! (IS_DIRECTORY_SEP (o[0]) && IS_DIRECTORY_SEP (o[1]))
896
#endif
897 898 899
#else /* not DOS_NT */
      /* Detect Unix absolute file names (/... alone is not absolute on
	 DOS or Windows).  */
900
	&& ! (IS_DIRECTORY_SEP (o[0]))
901
#endif /* not DOS_NT */
902 903 904
	)
      {
	struct gcpro gcpro1;
905

906 907 908 909 910
	GCPRO1 (name);
	default_directory = Fexpand_file_name (default_directory, Qnil);
	UNGCPRO;
      }
  }
911
  name = FILE_SYSTEM_CASE (name);
912
  multibyte = STRING_MULTIBYTE (name);
913 914 915 916 917 918 919 920 921 922 923 924
  if (multibyte != STRING_MULTIBYTE (default_directory))
    {
      if (multibyte)
	default_directory = string_to_multibyte (default_directory);
      else
	{
	  name = string_to_multibyte (name);
	  multibyte = 1;
	}
    }

  nm = SDATA (name);
925
  nm_in_name = 1;
926

927
#ifdef DOS_NT
928 929 930
  /* We will force directory separators to be either all \ or /, so make
     a local copy to modify, even if there ends up being no change. */
  nm = strcpy (alloca (strlen (nm) + 1), nm);
931
  nm_in_name = 0;
932

933 934 935 936 937 938 939
  /* Note if special escape prefix is present, but remove for now.  */
  if (nm[0] == '/' && nm[1] == ':')
    {
      is_escaped = 1;
      nm += 2;
    }

940
  /* Find and remove drive specifier if present; this makes nm absolute
941 942 943 944 945 946 947
     even if the rest of the name appears to be relative.  Only look for
     drive specifier at the beginning.  */
  if (IS_DRIVE (nm[0]) && IS_DEVICE_SEP (nm[1]))
    {
      drive = nm[0];
      nm += 2;
    }
948 949 950 951 952 953 954

#ifdef WINDOWSNT
  /* If we see "c://somedir", we want to strip the first slash after the
     colon when stripping the drive letter.  Otherwise, this expands to
     "//somedir".  */
  if (drive && IS_DIRECTORY_SEP (nm[0]) && IS_DIRECTORY_SEP (nm[1]))
    nm++;
955

956 957 958 959 960
  /* Discard any previous drive specifier if nm is now in UNC format. */
  if (IS_DIRECTORY_SEP (nm[0]) && IS_DIRECTORY_SEP (nm[1]))
    {
      drive = 0;
    }
961 962
#endif /* WINDOWSNT */
#endif /* DOS_NT */
963