files.el 103 KB
Newer Older
Eric S. Raymond's avatar
Eric S. Raymond committed
1 2
;;; files.el --- file input and output commands for Emacs

Roland McGrath's avatar
Roland McGrath committed
3
;; Copyright (C) 1985, 86, 87, 92, 93, 94, 1995 Free Software Foundation, Inc.
Roland McGrath's avatar
Roland McGrath committed
4

Eric S. Raymond's avatar
Eric S. Raymond committed
5 6
;; Maintainer: FSF

Roland McGrath's avatar
Roland McGrath committed
7 8 9 10
;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
Eric S. Raymond's avatar
Eric S. Raymond committed
11
;; the Free Software Foundation; either version 2, or (at your option)
Roland McGrath's avatar
Roland McGrath committed
12 13 14 15 16 17 18 19
;; any later version.

;; 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
20 21 22
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
Roland McGrath's avatar
Roland McGrath committed
23

24 25 26 27 28 29
;;; Commentary:

;; Defines most of Emacs's file- and directory-handling functions,
;; including basic file visiting, backup generation, link handling,
;; ITS-id version control, load- and write-hook handling, and the like.

Eric S. Raymond's avatar
Eric S. Raymond committed
30 31
;;; Code:

Roland McGrath's avatar
Roland McGrath committed
32
(defconst delete-auto-save-files t
33
  "*Non-nil means delete auto-save file when a buffer is saved or killed.")
Roland McGrath's avatar
Roland McGrath committed
34 35 36 37 38 39 40 41 42

(defconst directory-abbrev-alist
  nil
  "*Alist of abbreviations for file directories.
A list of elements of the form (FROM . TO), each meaning to replace
FROM with TO when it appears in a directory name.  This replacement is
done when setting up the default directory of a newly visited file.
*Every* FROM string should start with `^'.

43 44 45
Do not use `~' in the TO strings.
They should be ordinary absolute directory names.

Roland McGrath's avatar
Roland McGrath committed
46 47 48 49 50 51
Use this feature when you have directories which you normally refer to
via absolute symbolic links.  Make TO the name of the link, and FROM
the name it is linked to.")

;;; Turn off backup files on VMS since it has version numbers.
(defconst make-backup-files (not (eq system-type 'vax-vms))
52
  "*Non-nil means make a backup of a file the first time it is saved.
Roland McGrath's avatar
Roland McGrath committed
53 54 55 56 57 58 59 60 61 62 63 64 65 66
This can be done by renaming the file or by copying.

Renaming means that Emacs renames the existing file so that it is a
backup file, then writes the buffer into a new file.  Any other names
that the old file had will now refer to the backup file.  The new file
is owned by you and its group is defaulted.

Copying means that Emacs copies the existing file into the backup
file, then writes the buffer on top of the existing file.  Any other
names that the old file had will now refer to the new (edited) file.
The file's owner and group are unchanged.

The choice of renaming or copying is controlled by the variables
`backup-by-copying', `backup-by-copying-when-linked' and
67
`backup-by-copying-when-mismatch'.  See also `backup-inhibited'.")
Roland McGrath's avatar
Roland McGrath committed
68 69 70 71

;; Do this so that local variables based on the file name
;; are not overridden by the major mode.
(defvar backup-inhibited nil
72 73 74
  "Non-nil means don't make a backup, regardless of the other parameters.
This variable is intended for use by making it local to a buffer.
But it is local only if you make it local.")
Roland McGrath's avatar
Roland McGrath committed
75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106
(put 'backup-inhibited 'permanent-local t)

(defconst backup-by-copying nil
 "*Non-nil means always use copying to create backup files.
See documentation of variable `make-backup-files'.")

(defconst backup-by-copying-when-linked nil
 "*Non-nil means use copying to create backups for files with multiple names.
This causes the alternate names to refer to the latest version as edited.
This variable is relevant only if `backup-by-copying' is nil.")

(defconst backup-by-copying-when-mismatch nil
  "*Non-nil means create backups by copying if this preserves owner or group.
Renaming may still be used (subject to control of other variables)
when it would not result in changing the owner or group of the file;
that is, for files which are owned by you and whose group matches
the default for a new file created there by you.
This variable is relevant only if `backup-by-copying' is nil.")

(defvar backup-enable-predicate
  '(lambda (name)
     (or (< (length name) 5)
	 (not (string-equal "/tmp/" (substring name 0 5)))))
  "Predicate that looks at a file name and decides whether to make backups.
Called with an absolute file name as argument, it returns t to enable backup.")

(defconst buffer-offer-save nil
  "*Non-nil in a buffer means offer to save the buffer on exit
even if the buffer is not visiting a file.
Automatically local in all buffers.")
(make-variable-buffer-local 'buffer-offer-save)

107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124
(defconst find-file-existing-other-name nil
  "*Non-nil means find a file under alternative names, in existing buffers.
This means if any existing buffer is visiting the file you want
under another name, you get the existing buffer instead of a new buffer.")

(defconst find-file-visit-truename nil
  "*Non-nil means visit a file under its truename.
The truename of a file is found by chasing all links
both at the file level and at the levels of the containing directories.")

(defvar buffer-file-number nil
  "The device number and file number of the file visited in the current buffer.
The value is a list of the form (FILENUM DEVNUM).
This pair of numbers uniquely identifies the file.
If the buffer is visiting a new file, the value is nil.")
(make-variable-buffer-local 'buffer-file-number)
(put 'buffer-file-number 'permanent-local t)

Roland McGrath's avatar
Roland McGrath committed
125 126
(defconst file-precious-flag nil
  "*Non-nil means protect against I/O errors while saving files.
Karl Heuer's avatar
Karl Heuer committed
127
Some modes set this non-nil in particular buffers.
128 129 130 131 132 133 134

This feature works by writing the new contents into a temporary file
and then renaming the temporary file to replace the original.
In this way, any I/O error in writing leaves the original untouched,
and there is never any instant where the file is nonexistent.

Note that this feature forces backups to be made by copying.
Karl Heuer's avatar
Karl Heuer committed
135 136
Yet, at the same time, saving a precious file
breaks any hard links between it and other files.")
Roland McGrath's avatar
Roland McGrath committed
137 138 139 140 141

(defvar version-control nil
  "*Control use of version numbers for backup files.
t means make numeric backup versions unconditionally.
nil means make them for files that have some already.
142
`never' means do not make them.")
Roland McGrath's avatar
Roland McGrath committed
143 144 145 146

(defvar dired-kept-versions 2
  "*When cleaning directory, number of versions to keep.")

147 148 149
(defvar delete-old-versions nil
  "*If t, delete excess backup versions silently.
If nil, ask confirmation.  Any other value prevents any trimming.")
Roland McGrath's avatar
Roland McGrath committed
150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174

(defvar kept-old-versions 2
  "*Number of oldest versions to keep when a new numbered backup is made.")

(defvar kept-new-versions 2
  "*Number of newest versions to keep when a new numbered backup is made.
Includes the new backup.  Must be > 0")

(defconst require-final-newline nil
  "*Value of t says silently ensure a file ends in a newline when it is saved.
Non-nil but not t says ask user whether to add a newline when there isn't one.
nil means don't add newlines.")

(defconst auto-save-default t
  "*Non-nil says by default do auto-saving of every file-visiting buffer.")

(defconst auto-save-visited-file-name nil
  "*Non-nil says auto-save a buffer in the file it is visiting, when practical.
Normally auto-save files are written under other names.")

(defconst save-abbrevs nil
  "*Non-nil means save word abbrevs too when files are saved.
Loading an abbrev file sets this to t.")

(defconst find-file-run-dired t
175
  "*Non-nil says run dired if `find-file' is given the name of a directory.")
Roland McGrath's avatar
Roland McGrath committed
176

177 178
;;;It is not useful to make this a local variable.
;;;(put 'find-file-not-found-hooks 'permanent-local t)
Roland McGrath's avatar
Roland McGrath committed
179 180 181 182 183 184
(defvar find-file-not-found-hooks nil
  "List of functions to be called for `find-file' on nonexistent file.
These functions are called as soon as the error is detected.
`buffer-file-name' is already set up.
The functions are called in the order given until one of them returns non-nil.")

185 186
;;;It is not useful to make this a local variable.
;;;(put 'find-file-hooks 'permanent-local t)
Roland McGrath's avatar
Roland McGrath committed
187 188 189 190 191 192 193 194
(defvar find-file-hooks nil
  "List of functions to be called after a buffer is loaded from a file.
The buffer's local variables (if any) will have been processed before the
functions are called.")

(defvar write-file-hooks nil
  "List of functions to be called before writing out a buffer to a file.
If one of them returns non-nil, the file is considered already written
Jim Blandy's avatar
Jim Blandy committed
195 196 197
and the rest are not called.
These hooks are considered to pertain to the visited file.
So this list is cleared if you change the visited file name.
198 199 200

Don't make this variable buffer-local; instead, use `local-write-file-hooks'.
See also `write-contents-hooks'.")
201 202
;;; However, in case someone does make it local...
(put 'write-file-hooks 'permanent-local t)
203 204 205 206

(defvar local-write-file-hooks nil
  "Just like `write-file-hooks', except intended for per-buffer use.
The functions in this list are called before the ones in
207 208 209 210 211 212
`write-file-hooks'.

This variable is meant to be used for hooks that have to do with a
particular visited file.  Therefore, it is a permanent local, so that
changing the major mode does not clear it.  However, calling
`set-visited-file-name' does clear it.")
213 214
(make-variable-buffer-local 'local-write-file-hooks)
(put 'local-write-file-hooks 'permanent-local t)
Jim Blandy's avatar
Jim Blandy committed
215 216 217 218 219

(defvar write-contents-hooks nil
  "List of functions to be called before writing out a buffer to a file.
If one of them returns non-nil, the file is considered already written
and the rest are not called.
220 221 222 223

This variable is meant to be used for hooks that pertain to the
buffer's contents, not to the particular visited file; thus,
`set-visited-file-name' does not clear this variable; but changing the
224 225 226 227 228
major mode does clear it.

This variable automatically becomes buffer-local whenever it is set.
If you use `add-hooks' to add elements to the list, use nil for the
LOCAL argument.
229

Jim Blandy's avatar
Jim Blandy committed
230
See also `write-file-hooks'.")
231
(make-variable-buffer-local 'write-contents-hooks)
Roland McGrath's avatar
Roland McGrath committed
232 233 234 235 236 237 238 239 240 241

(defconst enable-local-variables t
  "*Control use of local-variables lists in files you visit.
The value can be t, nil or something else.
A value of t means local-variables lists are obeyed;
nil means they are ignored; anything else means query.

The command \\[normal-mode] always obeys local-variables lists
and ignores this variable.")

242
(defconst enable-local-eval 'maybe
243 244 245 246 247 248 249
  "*Control processing of the \"variable\" `eval' in a file's local variables.
The value can be t, nil or something else.
A value of t means obey `eval' variables;
nil means ignore them; anything else means query.

The command \\[normal-mode] always obeys local-variables lists
and ignores this variable.")
Roland McGrath's avatar
Roland McGrath committed
250 251 252

;; Avoid losing in versions where CLASH_DETECTION is disabled.
(or (fboundp 'lock-buffer)
253
    (defalias 'lock-buffer 'ignore))
Roland McGrath's avatar
Roland McGrath committed
254
(or (fboundp 'unlock-buffer)
255
    (defalias 'unlock-buffer 'ignore))
256 257 258 259 260 261 262 263

;; This hook function provides support for ange-ftp host name
;; completion.  It runs the usual ange-ftp hook, but only for
;; completion operations.  Having this here avoids the need
;; to load ange-ftp when it's not really in use.
(defun ange-ftp-completion-hook-function (op &rest args)
  (if (memq op '(file-name-completion file-name-all-completions))
      (apply 'ange-ftp-hook-function op args)
264 265 266 267 268
    (let ((inhibit-file-name-handlers
	   (cons 'ange-ftp-completion-hook-function
		 (and (eq inhibit-file-name-operation op)
		      inhibit-file-name-handlers)))
	  (inhibit-file-name-operation op))
269
      (apply op args))))
270 271 272 273 274 275 276

(defun convert-standard-filename (filename)
  "Convert a standard file's name to something suitable for the current OS.
This function's standard definition is trivial; it just returns the argument.
However, on some systems, the function is redefined
with a definition that really does change some file names."
  filename)
Roland McGrath's avatar
Roland McGrath committed
277 278 279 280 281 282

(defun pwd ()
  "Show the current default directory."
  (interactive nil)
  (message "Directory %s" default-directory))

283 284 285 286
(defvar cd-path nil
  "Value of the CDPATH environment variable, as a list.
Not actually set up until the first time you you use it.")

287 288 289
(defvar path-separator ":"
  "Character used to separate concatenated paths.")

290 291 292 293
(defun parse-colon-path (cd-path)
  "Explode a colon-separated list of paths into a string list."
  (and cd-path
       (let (cd-prefix cd-list (cd-start 0) cd-colon)
294 295
	 (setq cd-path (concat cd-path path-separator))
	 (while (setq cd-colon (string-match path-separator cd-path cd-start))
296
	   (setq cd-list
297
		 (nconc cd-list
298 299 300
			(list (if (= cd-start cd-colon)
				   nil
				(substitute-in-file-name
301 302
				 (file-name-as-directory
				  (substring cd-path cd-start cd-colon)))))))
303 304 305 306
	   (setq cd-start (+ cd-colon 1)))
	 cd-list)))

(defun cd-absolute (dir)
307
  "Change current directory to given absolute file name DIR."
308 309
  ;; Put the name into directory syntax now,
  ;; because otherwise expand-file-name may give some bad results.
Roland McGrath's avatar
Roland McGrath committed
310 311
  (if (not (eq system-type 'vax-vms))
      (setq dir (file-name-as-directory dir)))
312
  (setq dir (abbreviate-file-name (expand-file-name dir)))
Roland McGrath's avatar
Roland McGrath committed
313 314 315 316
  (if (not (file-directory-p dir))
      (error "%s is not a directory" dir)
    (if (file-executable-p dir)
	(setq default-directory dir)
317
      (error "Cannot cd to %s:  Permission denied" dir))))
Roland McGrath's avatar
Roland McGrath committed
318

319 320
(defun cd (dir)
  "Make DIR become the current buffer's default directory.
321 322
If your environment includes a `CDPATH' variable, try each one of that
colon-separated list of directories when resolving a relative directory name."
323 324
  (interactive
   (list (read-file-name "Change default directory: "
325 326 327
			 default-directory default-directory
			 (and (member cd-path '(nil ("./")))
			      (null (getenv "CDPATH"))))))
328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343
  (if (file-name-absolute-p dir)
      (cd-absolute (expand-file-name dir))
    (if (null cd-path)
	(let ((trypath (parse-colon-path (getenv "CDPATH"))))
	  (setq cd-path (or trypath (list "./")))))
    (if (not (catch 'found
	       (mapcar
		(function (lambda (x)
			    (let ((f (expand-file-name (concat x dir))))
			      (if (file-directory-p f)
				  (progn
				    (cd-absolute f)
				    (throw 'found t))))))
		cd-path)
	       nil))
	(error "No such directory found via CDPATH environment variable"))))
344

Roland McGrath's avatar
Roland McGrath committed
345 346 347 348 349 350 351 352 353 354
(defun load-file (file)
  "Load the Lisp file named FILE."
  (interactive "fLoad file: ")
  (load (expand-file-name file) nil nil t))

(defun load-library (library)
  "Load the library named LIBRARY.
This is an interface to the function `load'."
  (interactive "sLoad library: ")
  (load library))
355

Karl Heuer's avatar
Karl Heuer committed
356
(defun file-local-copy (file &optional buffer)
357 358 359
  "Copy the file FILE into a temporary file on this machine.
Returns the name of the local copy, or nil, if FILE is directly
accessible."
360
  (let ((handler (find-file-name-handler file 'file-local-copy)))
361 362 363
    (if handler
	(funcall handler 'file-local-copy file)
      nil)))
364

365
(defun file-truename (filename &optional counter prev-dirs)
366 367 368
  "Return the truename of FILENAME, which should be absolute.
The truename of a file name is found by chasing symbolic links
both at the level of the file and at the level of the directories
369 370 371 372 373 374 375 376
containing it, until no links are left at any level.

The arguments COUNTER and PREV-DIRS are used only in recursive calls.
Do not specify them in other calls."
  ;; COUNTER can be a cons cell whose car is the count of how many more links
  ;; to chase before getting an error.
  ;; PREV-DIRS can be a cons cell whose car is an alist
  ;; of truenames we've just recently computed.
377 378 379

  ;; The last test looks dubious, maybe `+' is meant here?  --simon.
  (if (or (string= filename "") (string= filename "~")
380 381
	  (and (string= (substring filename 0 1) "~")
	       (string-match "~[^/]*" filename)))
382 383 384 385
      (progn
	(setq filename (expand-file-name filename))
	(if (string= filename "")
	    (setq filename "/"))))
386
  (or counter (setq counter (list 100)))
387 388 389 390 391 392 393 394 395
  (let (done
	;; For speed, remove the ange-ftp completion handler from the list.
	;; We know it's not needed here.
	;; For even more speed, do this only on the outermost call.
	(file-name-handler-alist
	 (if prev-dirs file-name-handler-alist
	   (let ((tem (copy-sequence file-name-handler-alist)))
	     (delq (rassq 'ange-ftp-completion-hook-function tem) tem)))))
    (or prev-dirs (setq prev-dirs (list nil)))
396 397 398 399 400 401 402 403 404 405 406 407
    ;; If this file directly leads to a link, process that iteratively
    ;; so that we don't use lots of stack.
    (while (not done)
      (setcar counter (1- (car counter)))
      (if (< (car counter) 0)
	  (error "Apparent cycle of symbolic links for %s" filename))
      (let ((handler (find-file-name-handler filename 'file-truename)))
	;; For file name that has a special handler, call handler.
	;; This is so that ange-ftp can save time by doing a no-op.
	(if handler
	    (setq filename (funcall handler 'file-truename filename)
		  done t)
408
	  (let ((dir (or (file-name-directory filename) default-directory))
409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446
		target dirfile)
	    ;; Get the truename of the directory.
	    (setq dirfile (directory-file-name dir))
	    ;; If these are equal, we have the (or a) root directory.
	    (or (string= dir dirfile)
		;; If this is the same dir we last got the truename for,
		;; save time--don't recalculate.
		(if (assoc dir (car prev-dirs))
		    (setq dir (cdr (assoc dir (car prev-dirs))))
		  (let ((old dir)
			(new (file-name-as-directory (file-truename dirfile counter prev-dirs))))
		    (setcar prev-dirs (cons (cons old new) (car prev-dirs)))
		    (setq dir new))))
	    (if (equal ".." (file-name-nondirectory filename))
		(setq filename
		      (directory-file-name (file-name-directory (directory-file-name dir)))
		      done t)
	      (if (equal "." (file-name-nondirectory filename))
		  (setq filename (directory-file-name dir)
			done t)
		;; Put it back on the file name.
		(setq filename (concat dir (file-name-nondirectory filename)))
		;; Is the file name the name of a link?
		(setq target (file-symlink-p filename))
		(if target
		    ;; Yes => chase that link, then start all over
		    ;; since the link may point to a directory name that uses links.
		    ;; We can't safely use expand-file-name here
		    ;; since target might look like foo/../bar where foo
		    ;; is itself a link.  Instead, we handle . and .. above.
		    (setq filename
			  (if (file-name-absolute-p target)
			      target
			    (concat dir target))
			  done nil)
		  ;; No, we are done!
		  (setq done t))))))))
    filename))
447

448 449 450 451 452 453 454 455
(defun file-chase-links (filename)
  "Chase links in FILENAME until a name that is not a link.
Does not examine containing directories for links,
unlike `file-truename'."
  (let (tem (count 100) (newname filename))
    (while (setq tem (file-symlink-p newname))
      (if (= count 0)
	  (error "Apparent cycle of symbolic links for %s" filename))
456 457 458 459
      ;; In the context of a link, `//' doesn't mean what Emacs thinks.
      (while (string-match "//+" tem)
	(setq tem (concat (substring tem 0 (1+ (match-beginning 0)))
			  (substring tem (match-end 0)))))
460 461 462 463
      ;; Handle `..' by hand, since it needs to work in the
      ;; target of any directory symlink.
      ;; This code is not quite complete; it does not handle
      ;; embedded .. in some cases such as ./../foo and foo/bar/../../../lose.
464
      (while (string-match "\\`\\.\\./" tem)
465 466 467 468 469 470 471 472 473
	(setq tem (substring tem 3))
	(setq newname (file-name-as-directory
		       ;; Do the .. by hand.
		       (directory-file-name
			(file-name-directory
			 ;; Chase links in the default dir of the symlink.
			 (file-chase-links
			  (directory-file-name
			   (file-name-directory newname))))))))
474 475 476
      (setq newname (expand-file-name tem (file-name-directory newname)))
      (setq count (1- count)))
    newname))
Roland McGrath's avatar
Roland McGrath committed
477 478 479 480 481 482 483

(defun switch-to-buffer-other-window (buffer)
  "Select buffer BUFFER in another window."
  (interactive "BSwitch to buffer in other window: ")
  (let ((pop-up-windows t))
    (pop-to-buffer buffer t)))

Jim Blandy's avatar
Jim Blandy committed
484 485 486 487
(defun switch-to-buffer-other-frame (buffer)
  "Switch to buffer BUFFER in another frame."
  (interactive "BSwitch to buffer in other frame: ")
  (let ((pop-up-frames t))
488 489
    (pop-to-buffer buffer t)
    (raise-frame (window-frame (selected-window)))))
Jim Blandy's avatar
Jim Blandy committed
490

Roland McGrath's avatar
Roland McGrath committed
491 492 493 494 495 496 497 498 499 500 501 502 503 504
(defun find-file (filename)
  "Edit file FILENAME.
Switch to a buffer visiting file FILENAME,
creating one if none already exists."
  (interactive "FFind file: ")
  (switch-to-buffer (find-file-noselect filename)))

(defun find-file-other-window (filename)
  "Edit file FILENAME, in another window.
May create a new window, or reuse an existing one.
See the function `display-buffer'."
  (interactive "FFind file in other window: ")
  (switch-to-buffer-other-window (find-file-noselect filename)))

Jim Blandy's avatar
Jim Blandy committed
505 506 507
(defun find-file-other-frame (filename)
  "Edit file FILENAME, in another frame.
May create a new frame, or reuse an existing one.
Jim Blandy's avatar
Jim Blandy committed
508
See the function `display-buffer'."
Jim Blandy's avatar
Jim Blandy committed
509 510
  (interactive "FFind file in other frame: ")
  (switch-to-buffer-other-frame (find-file-noselect filename)))
Jim Blandy's avatar
Jim Blandy committed
511

Roland McGrath's avatar
Roland McGrath committed
512 513 514 515 516 517
(defun find-file-read-only (filename)
  "Edit file FILENAME but don't allow changes.
Like \\[find-file] but marks buffer as read-only.
Use \\[toggle-read-only] to permit editing."
  (interactive "fFind file read-only: ")
  (find-file filename)
518 519
  (setq buffer-read-only t)
  (current-buffer))
Roland McGrath's avatar
Roland McGrath committed
520 521 522 523 524 525

(defun find-file-read-only-other-window (filename)
  "Edit file FILENAME in another window but don't allow changes.
Like \\[find-file-other-window] but marks buffer as read-only.
Use \\[toggle-read-only] to permit editing."
  (interactive "fFind file read-only other window: ")
526
  (find-file-other-window filename)
527 528
  (setq buffer-read-only t)
  (current-buffer))
Roland McGrath's avatar
Roland McGrath committed
529

Jim Blandy's avatar
Jim Blandy committed
530 531 532
(defun find-file-read-only-other-frame (filename)
  "Edit file FILENAME in another frame but don't allow changes.
Like \\[find-file-other-frame] but marks buffer as read-only.
Jim Blandy's avatar
Jim Blandy committed
533
Use \\[toggle-read-only] to permit editing."
Jim Blandy's avatar
Jim Blandy committed
534 535
  (interactive "fFind file read-only other frame: ")
  (find-file-other-frame filename)
536 537
  (setq buffer-read-only t)
  (current-buffer))
Jim Blandy's avatar
Jim Blandy committed
538

539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558
(defun find-alternate-file-other-window (filename)
  "Find file FILENAME as a replacement for the file in the next window.
This command does not select that window."
  (interactive
   (save-selected-window
     (other-window 1)
     (let ((file buffer-file-name)
	   (file-name nil)
	   (file-dir nil))
       (and file
	    (setq file-name (file-name-nondirectory file)
		  file-dir (file-name-directory file)))
       (list (read-file-name
	      "Find alternate file: " file-dir nil nil file-name)))))
  (if (one-window-p)
      (find-file-other-window filename)
    (save-selected-window
      (other-window 1)
      (find-alternate-file filename))))

Roland McGrath's avatar
Roland McGrath committed
559 560 561 562 563 564 565 566 567 568 569
(defun find-alternate-file (filename)
  "Find file FILENAME, select its buffer, kill previous buffer.
If the current buffer now contains an empty file that you just visited
\(presumably by mistake), use this command to visit the file you really want."
  (interactive
   (let ((file buffer-file-name)
	 (file-name nil)
	 (file-dir nil))
     (and file
	  (setq file-name (file-name-nondirectory file)
		file-dir (file-name-directory file)))
Joseph Arceneaux's avatar
Joseph Arceneaux committed
570 571
     (list (read-file-name
	    "Find alternate file: " file-dir nil nil file-name))))
572
  (and (buffer-modified-p) (buffer-file-name)
Roland McGrath's avatar
Roland McGrath committed
573 574 575 576 577 578
       ;; (not buffer-read-only)
       (not (yes-or-no-p (format "Buffer %s is modified; kill anyway? "
				 (buffer-name))))
       (error "Aborted"))
  (let ((obuf (current-buffer))
	(ofile buffer-file-name)
579 580
	(onum buffer-file-number)
	(otrue buffer-file-truename)
Roland McGrath's avatar
Roland McGrath committed
581
	(oname (buffer-name)))
582 583
    (if (get-buffer " **lose**")
	(kill-buffer " **lose**"))
Roland McGrath's avatar
Roland McGrath committed
584 585
    (rename-buffer " **lose**")
    (setq buffer-file-name nil)
586 587
    (setq buffer-file-number nil)
    (setq buffer-file-truename nil)
Roland McGrath's avatar
Roland McGrath committed
588 589 590 591 592 593
    (unwind-protect
	(progn
	  (unlock-buffer)
	  (find-file filename))
      (cond ((eq obuf (current-buffer))
	     (setq buffer-file-name ofile)
594 595
	     (setq buffer-file-number onum)
	     (setq buffer-file-truename otrue)
Roland McGrath's avatar
Roland McGrath committed
596 597 598 599 600 601 602 603 604 605 606 607 608 609
	     (lock-buffer)
	     (rename-buffer oname))))
    (or (eq (current-buffer) obuf)
	(kill-buffer obuf))))

(defun create-file-buffer (filename)
  "Create a suitably named buffer for visiting FILENAME, and return it.
FILENAME (sans directory) is used unchanged if that name is free;
otherwise a string <2> or <3> or ... is appended to get an unused name."
  (let ((lastname (file-name-nondirectory filename)))
    (if (string= lastname "")
	(setq lastname filename))
    (generate-new-buffer lastname)))

Jim Blandy's avatar
Jim Blandy committed
610 611
(defun generate-new-buffer (name)
  "Create and return a buffer with a name based on NAME.
Richard M. Stallman's avatar
Richard M. Stallman committed
612
Choose the buffer's name using `generate-new-buffer-name'."
Jim Blandy's avatar
Jim Blandy committed
613 614
  (get-buffer-create (generate-new-buffer-name name)))

Jim Blandy's avatar
Jim Blandy committed
615 616 617
(defconst automount-dir-prefix "^/tmp_mnt/"
  "Regexp to match the automounter prefix in a directory name.")

618
(defvar abbreviated-home-dir nil
619
  "The user's homedir abbreviated according to `directory-abbrev-list'.")
620

Jim Blandy's avatar
Jim Blandy committed
621
(defun abbreviate-file-name (filename)
Richard M. Stallman's avatar
Richard M. Stallman committed
622
  "Return a version of FILENAME shortened using `directory-abbrev-alist'.
Jim Blandy's avatar
Jim Blandy committed
623
This also substitutes \"~\" for the user's home directory.
Richard M. Stallman's avatar
Richard M. Stallman committed
624
Type \\[describe-variable] directory-abbrev-alist RET for more information."
Jim Blandy's avatar
Jim Blandy committed
625 626 627 628 629
  ;; Get rid of the prefixes added by the automounter.
  (if (and (string-match automount-dir-prefix filename)
	   (file-exists-p (file-name-directory
			   (substring filename (1- (match-end 0))))))
      (setq filename (substring filename (1- (match-end 0)))))
Jim Blandy's avatar
Jim Blandy committed
630
  (let ((tail directory-abbrev-alist))
631 632
    ;; If any elt of directory-abbrev-alist matches this name,
    ;; abbreviate accordingly.
Jim Blandy's avatar
Jim Blandy committed
633 634 635 636 637
    (while tail
      (if (string-match (car (car tail)) filename)
	  (setq filename
		(concat (cdr (car tail)) (substring filename (match-end 0)))))
      (setq tail (cdr tail)))
638 639 640
    ;; Compute and save the abbreviated homedir name.
    ;; We defer computing this until the first time it's needed, to
    ;; give time for directory-abbrev-alist to be set properly.
641 642
    ;; We include a slash at the end, to avoid spurious matches
    ;; such as `/usr/foobar' when the home dir is `/usr/foo'.
643 644 645
    (or abbreviated-home-dir
	(setq abbreviated-home-dir
	      (let ((abbreviated-home-dir "$foo"))
646 647
		(concat "^" (abbreviate-file-name (expand-file-name "~"))
			"\\(/\\|$\\)"))))
648

649 650
    ;; If FILENAME starts with the abbreviated homedir,
    ;; make it start with `~' instead.
651 652 653
    (if (and (string-match abbreviated-home-dir filename)
	     ;; If the home dir is just /, don't change it.
	     (not (and (= (match-end 0) 1)
654
		       (= (aref filename 0) ?/)))
655 656
	     ;; MS-DOS root directories can come with a drive letter;
	     ;; Novell Netware allows drive letters beyond `Z:'.
657
	     (not (and (or (eq system-type 'ms-dos)
658
			   (eq system-type 'windows-nt))
659
		       (save-match-data
660
			 (string-match "^[a-zA-`]:/$" filename)))))
Jim Blandy's avatar
Jim Blandy committed
661
	(setq filename
662
	      (concat "~"
663
		      (substring filename (match-beginning 1) (match-end 1))
664
		      (substring filename (match-end 0)))))
Jim Blandy's avatar
Jim Blandy committed
665 666
    filename))

667 668 669 670 671 672 673
(defvar find-file-not-true-dirname-list nil
  "*List of logical names for which visiting shouldn't save the true dirname.
On VMS, when you visit a file using a logical name that searches a path,
you may or may not want the visited file name to record the specific
directory where the file was found.  If you *do not* want that, add the logical
name to this list as a string.")

674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690
(defun find-buffer-visiting (filename)
  "Return the buffer visiting file FILENAME (a string).
This is like `get-file-buffer', except that it checks for any buffer
visiting the same file, possibly under a different name.
If there is no such live buffer, return nil."
  (let ((buf (get-file-buffer filename))
	(truename (abbreviate-file-name (file-truename filename))))
    (or buf
	(let ((list (buffer-list)) found)
	  (while (and (not found) list)
	    (save-excursion
	      (set-buffer (car list))
	      (if (and buffer-file-name
		       (string= buffer-file-truename truename))
		  (setq found (car list))))
	    (setq list (cdr list)))
	  found)
691
	(let ((number (nthcdr 10 (file-attributes truename)))
692
	      (list (buffer-list)) found)
693 694 695 696
	  (and number
	       (while (and (not found) list)
		 (save-excursion
		   (set-buffer (car list))
697 698
		   (if (and buffer-file-name
			    (equal buffer-file-number number)
699 700 701 702 703 704 705
			    ;; Verify this buffer's file number
			    ;; still belongs to its file.
			    (file-exists-p buffer-file-name)
			    (equal (nthcdr 10 (file-attributes buffer-file-name))
				   number))
		       (setq found (car list))))
		 (setq list (cdr list))))
706 707
	  found))))

708 709 710 711 712 713 714 715 716
(defun insert-file-contents-literally (filename &optional visit beg end replace)
  "Like `insert-file-contents', q.v., but only reads in the file.
A buffer may be modified in several ways after reading into the buffer due
to advanced Emacs features, such as file-name-handlers, format decoding,
find-file-hooks, etc.
  This function ensures that none of these modifications will take place."
  (let ((file-name-handler-alist nil)
	(format-alist nil)
	(after-insert-file-functions nil)
717
	(find-buffer-file-type-function
718 719 720 721 722 723 724 725 726 727 728 729
	 (if (fboundp 'find-buffer-file-type)
	     (symbol-function 'find-buffer-file-type)
	   nil)))
    (unwind-protect
	(progn
	  (fset 'find-buffer-file-type (lambda (filename) t))
	  (insert-file-contents filename visit beg end replace))
      (if find-buffer-file-type-function
	  (fset 'find-buffer-file-type find-buffer-file-type-function)
	(fmakunbound 'find-buffer-file-type)))))

(defun find-file-noselect (filename &optional nowarn rawfile)
Roland McGrath's avatar
Roland McGrath committed
730 731 732 733
  "Read file FILENAME into a buffer and return the buffer.
If a buffer exists visiting FILENAME, return that one, but
verify that the file has not changed since visited or saved.
The buffer is not selected, just returned to the caller."
Jim Blandy's avatar
Jim Blandy committed
734 735 736
  (setq filename
	(abbreviate-file-name
	 (expand-file-name filename)))
Roland McGrath's avatar
Roland McGrath committed
737 738
  (if (file-directory-p filename)
      (if find-file-run-dired
739 740 741
	  (dired-noselect (if find-file-visit-truename
			      (abbreviate-file-name (file-truename filename))
			    filename))
Roland McGrath's avatar
Roland McGrath committed
742
	(error "%s is a directory." filename))
743 744 745 746
    (let* ((buf (get-file-buffer filename))
	   (truename (abbreviate-file-name (file-truename filename)))
	   (number (nthcdr 10 (file-attributes truename)))
	   ;; Find any buffer for a file which has same truename.
747
	   (other (and (not buf) (find-buffer-visiting filename)))
748 749
	   error)
      ;; Let user know if there is a buffer with the same truename.
750 751
      (if other
	  (progn
752 753 754 755
	    (or nowarn
		(string-equal filename (buffer-file-name other))
		(message "%s and %s are the same file"
			 filename (buffer-file-name other)))
756 757 758
	    ;; Optionally also find that buffer.
	    (if (or find-file-existing-other-name find-file-visit-truename)
		(setq buf other))))
Roland McGrath's avatar
Roland McGrath committed
759 760 761 762 763 764
      (if buf
	  (or nowarn
	      (verify-visited-file-modtime buf)
	      (cond ((not (file-exists-p filename))
		     (error "File %s no longer exists!" filename))
		    ((yes-or-no-p
765 766 767 768 769 770 771 772 773 774 775 776 777
		      (if (string= (file-name-nondirectory filename)
				   (buffer-name buf))
			  (format
			   (if (buffer-modified-p buf)
	"File %s changed on disk.  Discard your edits? "
	"File %s changed on disk.  Reread from disk? ")
			   (file-name-nondirectory filename))
			(format
			 (if (buffer-modified-p buf)
      "File %s changed on disk.  Discard your edits in %s? "
      "File %s changed on disk.  Reread from disk into %s? ")
			 (file-name-nondirectory filename)
			 (buffer-name buf))))
Roland McGrath's avatar
Roland McGrath committed
778 779 780 781
		     (save-excursion
		       (set-buffer buf)
		       (revert-buffer t t)))))
	(save-excursion
782 783 784 785 786 787 788
;;; The truename stuff makes this obsolete.
;;;	  (let* ((link-name (car (file-attributes filename)))
;;;		 (linked-buf (and (stringp link-name)
;;;				  (get-file-buffer link-name))))
;;;	    (if (bufferp linked-buf)
;;;		(message "Symbolic link to file in buffer %s"
;;;			 (buffer-name linked-buf))))
Roland McGrath's avatar
Roland McGrath committed
789
	  (setq buf (create-file-buffer filename))
790
	  (set-buffer-major-mode buf)
Roland McGrath's avatar
Roland McGrath committed
791 792
	  (set-buffer buf)
	  (erase-buffer)
793 794 795 796 797 798 799 800 801 802 803 804 805
	  (if rawfile
	      (condition-case ()
		  (insert-file-contents-literally filename t)
		(file-error
		 ;; Unconditionally set error
		 (setq error t)))
	    (condition-case ()
		(insert-file-contents filename t)
	      (file-error
	       ;; Run find-file-not-found-hooks until one returns non-nil.
	       (or (run-hook-with-args-until-success 'find-file-not-found-hooks)
		   ;; If they fail too, set error.
		   (setq error t)))))
806
	  ;; Find the file's truename, and maybe use that as visited name.
807
	  (setq buffer-file-truename truename)
808 809 810 811 812 813 814 815 816 817
	  (setq buffer-file-number number)
	  ;; On VMS, we may want to remember which directory in a search list
	  ;; the file was found in.
	  (and (eq system-type 'vax-vms)
	       (let (logical)
		 (if (string-match ":" (file-name-directory filename))
		     (setq logical (substring (file-name-directory filename)
					      0 (match-beginning 0))))
		 (not (member logical find-file-not-true-dirname-list)))
	       (setq buffer-file-name buffer-file-truename))
818
	  (if find-file-visit-truename
819 820 821
	      (setq buffer-file-name
		    (setq filename
			  (expand-file-name buffer-file-truename))))
Roland McGrath's avatar
Roland McGrath committed
822 823 824 825 826 827 828 829
	  ;; Set buffer's default directory to that of the file.
	  (setq default-directory (file-name-directory filename))
	  ;; Turn off backup files for certain file names.  Since
	  ;; this is a permanent local, the major mode won't eliminate it.
	  (and (not (funcall backup-enable-predicate buffer-file-name))
	       (progn
		 (make-local-variable 'backup-inhibited)
		 (setq backup-inhibited t)))
830 831 832
	  (if rawfile
	      nil
	    (after-find-file error (not nowarn)))))
Roland McGrath's avatar
Roland McGrath committed
833 834
      buf)))

835 836
(defvar after-find-file-from-revert-buffer nil)

837
(defun after-find-file (&optional error warn noauto
838 839
				  after-find-file-from-revert-buffer
				  nomodes)
Roland McGrath's avatar
Roland McGrath committed
840 841
  "Called after finding a file and by the default revert function.
Sets buffer mode, parses local variables.
842
Optional args ERROR, WARN, and NOAUTO: ERROR non-nil means there was an
Roland McGrath's avatar
Roland McGrath committed
843 844
error in reading the file.  WARN non-nil means warn if there
exists an auto-save file more recent than the visited file.
845
NOAUTO means don't mess with auto-save mode.
846 847
Fourth arg AFTER-FIND-FILE-FROM-REVERT-BUFFER non-nil
 means this call was from `revert-buffer'.
848 849 850
Fifth arg NOMODES non-nil means don't alter the file's modes.
Finishes by calling the functions in `find-file-hooks'
unless NOMODES is non-nil."
Roland McGrath's avatar
Roland McGrath committed
851 852 853 854 855 856 857
  (setq buffer-read-only (not (file-writable-p buffer-file-name)))
  (if noninteractive
      nil
    (let* (not-serious
	   (msg
	    (cond ((and error (file-attributes buffer-file-name))
		   (setq buffer-read-only t)
858
		   "File exists, but cannot be read.")
Roland McGrath's avatar
Roland McGrath committed
859 860 861 862 863 864 865 866 867 868 869 870
		  ((not buffer-read-only)
		   (if (and warn
			    (file-newer-than-file-p (make-auto-save-file-name)
						    buffer-file-name))
		       "Auto save file is newer; consider M-x recover-file"
		     (setq not-serious t)
		     (if error "(New file)" nil)))
		  ((not error)
		   (setq not-serious t)
		   "Note: file is write protected")
		  ((file-attributes (directory-file-name default-directory))
		   "File not found and directory write-protected")
871 872
		  ((file-exists-p (file-name-directory buffer-file-name))
		   (setq buffer-read-only nil))
Roland McGrath's avatar
Roland McGrath committed
873
		  (t
Jim Blandy's avatar
Jim Blandy committed
874
		   (setq buffer-read-only nil)
875 876 877
		   (if (file-exists-p (file-name-directory (directory-file-name (file-name-directory buffer-file-name))))
		       "Use M-x make-dir RET RET to create the directory"
		     "Use C-u M-x make-dir RET RET to create directory and its parents")))))
Roland McGrath's avatar
Roland McGrath committed
878 879 880 881
      (if msg
	  (progn
	    (message msg)
	    (or not-serious (sit-for 1 nil t)))))
882
    (if (and auto-save-default (not noauto))
Roland McGrath's avatar
Roland McGrath committed
883
	(auto-save-mode t)))
884 885 886 887
  (if nomodes
      nil
    (normal-mode t)
    (run-hooks 'find-file-hooks)))
Roland McGrath's avatar
Roland McGrath committed
888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905

(defun normal-mode (&optional find-file)
  "Choose the major mode for this buffer automatically.
Also sets up any specified local variables of the file.
Uses the visited file name, the -*- line, and the local variables spec.

This function is called automatically from `find-file'.  In that case,
we may set up specified local variables depending on the value of
`enable-local-variables': if it is t, we do; if it is nil, we don't;
otherwise, we query.  `enable-local-variables' is ignored if you
run `normal-mode' explicitly."
  (interactive)
  (or find-file (funcall (or default-major-mode 'fundamental-mode)))
  (condition-case err
      (set-auto-mode)
    (error (message "File mode specification error: %s"
		    (prin1-to-string err))))
  (condition-case err
Jim Blandy's avatar
Jim Blandy committed
906 907 908
      (let ((enable-local-variables (or (not find-file)
					enable-local-variables)))
	(hack-local-variables))
Roland McGrath's avatar
Roland McGrath committed
909 910 911
    (error (message "File local-variables error: %s"
		    (prin1-to-string err)))))

912
(defvar auto-mode-alist
913
  '(("\\.te?xt\\'" . text-mode)
914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944
    ("\\.c\\'" . c-mode)
    ("\\.h\\'" . c-mode)
    ("\\.tex\\'" . tex-mode)
    ("\\.ltx\\'" . latex-mode)
    ("\\.el\\'" . emacs-lisp-mode)
    ("\\.mm\\'" . nroff-mode)
    ("\\.me\\'" . nroff-mode)
    ("\\.ms\\'" . nroff-mode)
    ("\\.man\\'" . nroff-mode)
    ("\\.scm\\'" . scheme-mode)
    ("\\.l\\'" . lisp-mode)
    ("\\.lisp\\'" . lisp-mode)
    ("\\.f\\'" . fortran-mode)
    ("\\.for\\'" . fortran-mode)
    ("\\.p\\'" . pascal-mode)
    ("\\.pas\\'" . pascal-mode)
    ("\\.mss\\'" . scribe-mode)
    ("\\.ad[abs]\\'" . ada-mode)
    ("\\.icn\\'" . icon-mode)
    ("\\.pl\\'" . perl-mode)
    ("\\.cc\\'" . c++-mode)
    ("\\.hh\\'" . c++-mode)
    ("\\.C\\'" . c++-mode)
    ("\\.H\\'" . c++-mode)
    ("\\.cpp\\'" . c++-mode)
    ("\\.cxx\\'" . c++-mode)
    ("\\.hxx\\'" . c++-mode)
    ("\\.c\\+\\+\\'" . c++-mode)
    ("\\.h\\+\\+\\'" . c++-mode)
    ("\\.mk\\'" . makefile-mode)
    ("[Mm]akefile\\(.in\\)?\\'" . makefile-mode)
Jim Blandy's avatar
Jim Blandy committed
945 946
;;; Less common extensions come here
;;; so more common ones above are found faster.
947
    ("\\.texinfo\\'" . texinfo-mode)
948
    ("\\.te?xi\\'" . texinfo-mode)
949
    ("\\.s\\'" . asm-mode)
950 951
    ("\\.S\\'" . asm-mode)
    ("\\.asm\\'" . asm-mode)
952 953 954 955 956 957
    ("ChangeLog\\'" . change-log-mode)
    ("change.log\\'" . change-log-mode)
    ("changelo\\'" . change-log-mode)
    ("ChangeLog.[0-9]+\\'" . change-log-mode)
    ("\\$CHANGE_LOG\\$\\.TXT" . change-log-mode)
    ("\\.scm\\.[0-9]*\\'" . scheme-mode)
958 959 960 961
    ("\\.c?sh\\'\\|\\.shar\\'\\|/\\.z?profile\\'" . sh-mode)
    ("/\\.\\(bash_profile\\|z?login\\|bash_login\\|z?logout\\)\\'" . sh-mode)
    ("/\\.\\(bash_logout\\|[kz]shrc\\|bashrc\\|t?cshrc\\|esrc\\)\\'" . sh-mode)
    ("/\\.\\([kz]shenv\\|xinitrc\\|startxrc\\|xsession\\)\\'" . sh-mode)
962 963 964
;;; The following should come after the ChangeLog pattern
;;; for the sake of ChangeLog.1, etc.
;;; and after the .scm.[0-9] pattern too.
965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989
    ("\\.[12345678]\\'" . nroff-mode)
    ("\\.TeX\\'" . tex-mode)
    ("\\.sty\\'" . latex-mode)
    ("\\.cls\\'" . latex-mode)		;LaTeX 2e class
    ("\\.bbl\\'" . latex-mode)
    ("\\.bib\\'" . bibtex-mode)
    ("\\.article\\'" . text-mode)
    ("\\.letter\\'" . text-mode)
    ("\\.tcl\\'" . tcl-mode)
    ("\\.f90\\'" . f90-mode)
    ("\\.lsp\\'" . lisp-mode)
    ("\\.awk\\'" . awk-mode)
    ("\\.prolog\\'" . prolog-mode)
    ("\\.tar\\'" . tar-mode)
    ("\\.\\(arc\\|zip\\|lzh\\|zoo\\)\\'" . archive-mode)
    ;; Mailer puts message to be edited in
    ;; /tmp/Re.... or Message
    ("^/tmp/Re" . text-mode)
    ("/Message[0-9]*\\'" . text-mode)
    ("/drafts/[0-9]+\\'" . mh-letter-mode)
    ;; some news reader is reported to use this
    ("^/tmp/fol/" . text-mode)
    ("\\.y\\'" . c-mode)
    ("\\.lex\\'" . c-mode)
    ("\\.oak\\'" . scheme-mode)
990
    ("\\.sgml?\\'" . sgml-mode)
991
    ("\\.dtd\\'" . sgml-mode)
992
    ("\\.s?html?\\'" . html-mode)
993 994 995 996 997 998 999
    ;; .emacs following a directory delimiter
    ;; in either Unix or VMS syntax.
    ("[]>:/]\\..*emacs\\'" . emacs-lisp-mode)
    ;; _emacs following a directory delimiter
    ;; in MsDos syntax
    ("[:/]_emacs\\'" . emacs-lisp-mode)
    ("\\.ml\\'" . lisp-mode))
Jim Blandy's avatar
Jim Blandy committed
1000 1001
  "\
Alist of filename patterns vs corresponding major mode functions.
1002 1003 1004 1005 1006 1007 1008 1009
Each element looks like (REGEXP . FUNCTION) or (REGEXP FUNCTION NON-NIL).
\(NON-NIL stands for anything that is not nil; the value does not matter.)
Visiting a file whose name matches REGEXP specifies FUNCTION as the
mode function to use.  FUNCTION will be called, unless it is nil.

If the element has the form (REGEXP FUNCTION NON-NIL), then after
calling FUNCTION (if it's not nil), we delete the suffix that matched
REGEXP and search the list again for another match.")
Jim Blandy's avatar
Jim Blandy committed
1010

1011 1012 1013
(defconst interpreter-mode-alist
  '(("perl" . perl-mode)
    ("wish" . tcl-mode)
1014
    ("wishx" . tcl-mode)
1015
    ("tcl" . tcl-mode)
1016
    ("tclsh" . tcl-mode)
1017
    ("awk" . awk-mode)
1018
    ("nawk" . awk-mode)
1019
    ("gawk" . awk-mode)
1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041
    ("scm" . scheme-mode)
    ("ash" . sh-mode)
    ("bash" . sh-mode)
    ("csh" . sh-mode)
    ("dtksh" . sh-mode)
    ("es" . sh-mode)
    ("itcsh" . sh-mode)
    ("jsh" . sh-mode)
    ("ksh" . sh-mode)
    ("oash" . sh-mode)
    ("pdksh" . sh-mode)
    ("rc" . sh-mode)
    ("sh" . sh-mode)
    ("sh5" . sh-mode)
    ("tcsh" . sh-mode)
    ("wksh" . sh-mode)
    ("wsh" . sh-mode)
    ("zsh" . sh-mode)
    ("tail" . text-mode)
    ("more" . text-mode)
    ("less" . text-mode)
    ("pg" . text-mode))
1042 1043 1044 1045 1046 1047 1048
  "Alist mapping interpreter names to major modes.
This alist applies to files whose first line starts with `#!'.
Each element looks like (INTERPRETER . MODE).
The car of each element is compared with
the name of the interpreter specified in the first line.
If it matches, mode MODE is selected.")

1049
(defconst inhibit-first-line-modes-regexps '("\\.tar\\'")
1050
  "List of regexps; if one matches a file name, don't look for `-*-'.")
1051

1052 1053 1054 1055 1056
(defconst inhibit-first-line-modes-suffixes nil
  "List of regexps for what to ignore, for `inhibit-first-line-modes-regexps'.
When checking `inhibit-first-line-modes-regexps', we first discard
from the end of the file name anything that matches one of these regexps.")

1057 1058 1059 1060
(defvar user-init-file
  "" ; set by command-line
  "File name including directory of user's initialization file.")

Roland McGrath's avatar
Roland McGrath committed
1061 1062
(defun set-auto-mode ()
  "Select major mode appropriate for current buffer.
1063 1064 1065 1066 1067 1068 1069
This checks for a -*- mode tag in the buffer's text,
compares the filename against the entries in `auto-mode-alist',
or checks the interpreter that runs this file against
`interpreter-mode-alist'.

It does not check for the `mode:' local variable in the
Local Variables section of the file; for that, use `hack-local-variables'.
Jim Blandy's avatar
Jim Blandy committed
1070

1071
If `enable-local-variables' is nil, this function does not check for a
Jim Blandy's avatar
Jim Blandy committed
1072
-*- mode tag."
Roland McGrath's avatar
Roland McGrath committed
1073
  ;; Look for -*-MODENAME-*- or -*- ... mode: MODENAME; ... -*-
1074
  (let (beg end done modes)
Roland McGrath's avatar
Roland McGrath committed
1075 1076 1077
    (save-excursion
      (goto-char (point-min))
      (skip-chars-forward " \t\n")
1078 1079
      (and enable-local-variables
	   ;; Don't look for -*- if this file name matches any
1080
	   ;; of the regexps in inhibit-first-line-modes-regexps.
1081
	   (let ((temp inhibit-first-line-modes-regexps)
1082 1083 1084
		 (name (if buffer-file-name
			   (file-name-sans-versions buffer-file-name)
			 (buffer-name))))
1085 1086 1087 1088 1089
	     (while (let ((sufs inhibit-first-line-modes-suffixes))
		      (while (and sufs (not (string-match (car sufs) name)))
			(setq sufs (cdr sufs)))
		      sufs)
	       (setq name (substring name 0 (match-beginning 0))))
1090
	     (while (and temp
1091
			 (not (string-match (car temp) name)))
1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116
	       (setq temp (cdr temp)))
	     (not temp))
	   (search-forward "-*-" (save-excursion
				   ;; If the file begins with "#!"
				   ;; (exec interpreter magic), look
				   ;; for mode frobs in the first two
				   ;; lines.  You cannot necessarily
				   ;; put them in the first line of
				   ;; such a file without screwing up
				   ;; the interpreter invocation.
				   (end-of-line (and (looking-at "^#!") 2))
				   (point)) t)
	   (progn
	     (skip-chars-forward " \t")
	     (setq beg (point))
	     (search-forward "-*-"
			     (save-excursion (end-of-line) (point))
			     t))
	   (progn
	     (forward-char -3)
	     (skip-chars-backward " \t")
	     (setq end (point))
	     (goto-char beg)
	     (if (save-excursion (search-forward ":" end t))
		 ;; Find all specifications for the `mode:' variable
Karl Heuer's avatar
Karl Heuer committed
1117
		 ;; and execute them left to right.
1118
		 (while (let ((case-fold-search t))
1119 1120 1121
			  (or (and (looking-at "mode:")
				   (goto-char (match-end 0)))
			      (re-search-forward "[ \t;]mode:" end t)))
1122 1123 1124 1125 1126 1127
		   (skip-chars-forward " \t")
		   (setq beg (point))
		   (if (search-forward ";" end t)
		       (forward-char -1)
		     (goto-char end))
		   (skip-chars-backward " \t")
1128 1129
		   (setq modes (cons (intern (concat (downcase (buffer-substring beg (point))) "-mode"))
				     modes)))
1130
	       ;; Simple -*-MODE-*- case.
1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149
	       (setq modes (cons (intern (concat (downcase (buffer-substring beg end))
						 "-mode"))
				 modes))))))
    ;; If we found modes to use, invoke them now,
    ;; outside the save-excursion.
    (if modes
	(progn (mapcar 'funcall modes)
	       (setq done t)))
    ;; If we didn't find a mode from a -*- line, try using the file name.
    (if (and (not done) buffer-file-name)
	(let ((name buffer-file-name)
	      (keep-going t))
	  ;; Remove backup-suffixes from file name.
	  (setq name (file-name-sans-versions name))
	  (while keep-going
	    (setq keep-going nil)
	    (let ((alist auto-mode-alist)
		  (mode nil))
	      ;; Find first matching alist entry.
1150
	      (let ((case-fold-search
1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166
		     (memq system-type '(vax-vms windows-nt))))
		(while (and (not mode) alist)
		  (if (string-match (car (car alist)) name)
		      (if (and (consp (cdr (car alist)))
			       (nth 2 (car alist)))
			  (progn
			    (setq mode (car (cdr (car alist)))
				  name (substring name 0 (match-beginning 0))
				  keep-going t))
			(setq mode (cdr (car alist))
			      keep-going nil)))
		  (setq alist (cdr alist))))
	      (if mode
		  (funcall mode)
		;; If we can't deduce a mode from the file name,
		;; look for an interpreter specified in the first line.
1167 1168
		;; As a special case, allow for things like "#!/bin/env perl",
		;; which finds the interpreter anywhere in $PATH.
1169 1170 1171
		(let ((interpreter
		       (save-excursion
			 (goto-char (point-min))
1172 1173 1174
			 (if (looking-at "#! *\\([^ \t\n]*/bin/env +\\)?\\([^ \t\n]+\\)")
			     (buffer-substring (match-beginning 2)
					       (match-end 2))
1175 1176 1177 1178 1179 1180 1181
			   "")))
		      elt)
		  ;; Map interpreter name to a mode.
		  (setq elt (assoc (file-name-nondirectory interpreter)
				   interpreter-mode-alist))
		  (if elt
		      (funcall (