1 ;;; autorevert.el --- revert buffers when files on disk change
3 ;; Copyright (C) 1997, 1998, 1999, 2001 Free Software Foundation, Inc.
5 ;; Author: Anders Lindgren <andersl@andersl.com>
6 ;; Keywords: convenience
10 ;; This file is part of GNU Emacs.
12 ;; GNU Emacs is free software; you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation; either version 2, or (at your option)
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs; see the file COPYING. If not, write to the
24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
25 ;; Boston, MA 02111-1307, USA.
31 ;; Whenever a file that Emacs is editing has been changed by another
32 ;; program the user normally has to execute the command `revert-buffer'
33 ;; to load the new content of the file into Emacs.
35 ;; This package contains two minor modes: Global Auto-Revert Mode and
36 ;; Auto-Revert Mode. Both modes automatically revert buffers
37 ;; whenever the corresponding files have been changed on disk.
39 ;; Auto-Revert Mode can be activated for individual buffers.
40 ;; Global Auto-Revert Mode applies to all file buffers.
42 ;; Both modes operate by checking the time stamp of all files at
43 ;; intervals of `auto-revert-interval'. The default is every five
44 ;; seconds. The check is aborted whenever the user actually uses
45 ;; Emacs. You should never even notice that this package is active
46 ;; (except that your buffers will be reverted, of course).
50 ;; Go to the appropriate buffer and press:
51 ;; M-x auto-revert-mode RET
53 ;; To activate Global Auto-Revert Mode, press:
54 ;; M-x global-auto-revert-mode RET
56 ;; To activate Global Auto-Revert Mode every time Emacs is started
57 ;; customise the option `global-auto-revert-mode' or the following
58 ;; line could be added to your ~/.emacs:
59 ;; (global-auto-revert-mode 1)
61 ;; The function `turn-on-auto-revert-mode' could be added to any major
62 ;; mode hook to activate Auto-Revert Mode for all buffers in that
63 ;; mode. For example, the following line will activate Auto-Revert
64 ;; Mode in all C mode buffers:
66 ;; (add-hook 'c-mode-hook 'turn-on-auto-revert-mode)
73 (autoload 'dired-get-filename "dired")
74 (autoload 'vc-workfile-version "vc-hooks")
75 (autoload 'vc-mode-line "vc-hooks")
78 (defvar dired-directory)
85 ;; The two modes will be placed next to Auto Save Mode under the
86 ;; Files group under Emacs.
88 (defgroup auto-revert nil
89 "Revert individual buffers when files on disk change.
91 Auto-Revert Mode can be activated for individual buffer.
92 Global Auto-Revert Mode applies to all buffers."
99 ;; Autoload for the benefit of `make-mode-line-mouse-sensitive'.
101 (defvar auto-revert-mode nil
102 "*Non-nil when Auto-Revert Mode is active.
103 Never set this variable directly, use the command `auto-revert-mode' instead.")
104 (put 'auto-revert-mode 'permanent-local t)
106 (defvar auto-revert-timer nil
107 "Timer used by Auto-Revert Mode.")
109 (defcustom auto-revert-interval 5
110 "Time, in seconds, between Auto-Revert Mode file checks.
111 The value may be an integer or floating point number.
113 If a timer is already active, there are two ways to make sure
114 that the new value will take effect immediately. You can set
115 this variable through Custom or you can call the command
116 `auto-revert-set-timer' after setting the variable. Otherwise,
117 the new value will take effect the first time Auto Revert Mode
118 calls `auto-revert-set-timer' for internal reasons or in your
119 next editing session."
122 :set (lambda (variable value)
123 (set-default variable value)
124 (and (boundp 'auto-revert-timer)
126 (auto-revert-set-timer))))
128 (defcustom auto-revert-stop-on-user-input t
129 "When non-nil Auto-Revert Mode stops checking files on user input."
133 (defcustom auto-revert-verbose t
134 "When nil, Auto-Revert Mode will not generate any messages.
135 When non-nil, a message is generated whenever a file is reverted."
139 (defcustom auto-revert-mode-text " ARev"
140 "String to display in the mode line when Auto-Revert Mode is active.
142 \(When the string is not empty, make sure that it has a leading space.)"
143 :tag "Auto Revert Mode Text" ; To separate it from `global-...'
147 (defcustom auto-revert-mode-hook nil
148 "Functions to run when Auto-Revert Mode is activated."
149 :tag "Auto Revert Mode Hook" ; To separate it from `global-...'
153 (defcustom global-auto-revert-mode-text ""
154 "String to display when Global Auto-Revert Mode is active.
156 The default is nothing since when this mode is active this text doesn't
157 vary over time, or between buffers. Hence mode line text
158 would only waste precious space."
162 (defcustom global-auto-revert-mode-hook nil
163 "Hook called when Global Auto-Revert Mode is activated."
167 (defcustom global-auto-revert-non-file-buffers nil
168 "When nil only file buffers are reverted by Global Auto-Revert Mode.
170 When non-nil, both file buffers and buffers with a custom
171 `revert-buffer-function' and a `buffer-stale-function' are
172 reverted by Global Auto-Revert Mode.
174 Use this option with care since it could lead to excessive reverts.
175 Note also that for some non-file buffers the check whether the
176 buffer needs updating may be imperfect, due to efficiency
177 considerations, and may not take all information listed in the
178 buffer into account. Hence, a non-nil value for this option does
179 not necessarily make manual updates useless for non-file buffers."
183 (defcustom global-auto-revert-ignore-modes '()
184 "List of major modes Global Auto-Revert Mode should not check."
186 :type '(repeat sexp))
188 (defcustom auto-revert-load-hook nil
189 "Functions to run when Auto-Revert Mode is first loaded."
194 (defvar global-auto-revert-ignore-buffer nil
195 "*When non-nil, Global Auto-Revert Mode will not revert this buffer.
197 This variable becomes buffer local when set in any fashion.")
198 (make-variable-buffer-local 'global-auto-revert-ignore-buffer)
200 ;; Internal variables:
202 (defvar auto-revert-buffer-list '()
203 "List of buffers in Auto-Revert Mode.
205 Note that only Auto-Revert Mode, never Global Auto-Revert Mode, adds
206 buffers to this list.
208 The timer function `auto-revert-buffers' is responsible for purging
209 the list of old buffers.")
211 (defvar auto-revert-remaining-buffers '()
212 "Buffers not checked when user input stopped execution.")
218 (define-minor-mode auto-revert-mode
219 "Toggle reverting buffer when file on disk changes.
221 With arg, turn Auto Revert mode on if and only if arg is positive.
222 This is a minor mode that affects only the current buffer.
223 Use `global-auto-revert-mode' to automatically revert all buffers."
224 nil auto-revert-mode-text nil
226 (if (not (memq (current-buffer) auto-revert-buffer-list))
227 (push (current-buffer) auto-revert-buffer-list))
228 (setq auto-revert-buffer-list
229 (delq (current-buffer) auto-revert-buffer-list)))
230 (auto-revert-set-timer)
231 (when auto-revert-mode
232 (auto-revert-buffers)))
236 (defun turn-on-auto-revert-mode ()
237 "Turn on Auto-Revert Mode.
239 This function is designed to be added to hooks, for example:
240 (add-hook 'c-mode-hook 'turn-on-auto-revert-mode)"
241 (auto-revert-mode 1))
245 (define-minor-mode global-auto-revert-mode
246 "Revert any buffer when file on disk changes.
248 With arg, turn Auto Revert mode on globally if and only if arg is positive.
249 This is a minor mode that affects all buffers.
250 Use `auto-revert-mode' to revert a particular buffer."
251 :global t :group 'auto-revert :lighter global-auto-revert-mode-text
252 (auto-revert-set-timer)
253 (when global-auto-revert-mode
254 (auto-revert-buffers)))
257 (defun auto-revert-set-timer ()
258 "Restart or cancel the timer used by Auto-Revert Mode.
259 If such a timer is running, cancel it. Start a new timer if
260 Global Auto-Revert Mode is active or if Auto-Revert Mode is active
261 in some buffer. Restarting the timer ensures that Auto-Revert Mode
262 will use an up-to-date value of `auto-revert-interval'"
264 (if (timerp auto-revert-timer)
265 (cancel-timer auto-revert-timer))
266 (setq auto-revert-timer
267 (if (or global-auto-revert-mode auto-revert-buffer-list)
268 (run-with-timer auto-revert-interval
270 'auto-revert-buffers)
273 (defun auto-revert-active-p ()
274 "Check if auto-revert is active (in current buffer or globally)."
277 global-auto-revert-mode
278 (not global-auto-revert-ignore-buffer)
279 (not (memq major-mode
280 global-auto-revert-ignore-modes)))))
282 (defun auto-revert-vc-cvs-file-version (file)
283 "Get version of FILE by reading control file on disk."
284 (let* ((control "CVS/Entries")
285 (name (file-name-nondirectory file))
286 (path (format "%s/%s"
287 (file-name-directory file)
289 (when (file-exists-p path)
291 (insert-file-contents-literally path)
292 (goto-char (point-min))
293 (when (re-search-forward
294 ;; /file.txt/1.3/Mon Sep 15 18:43:20 2003//
295 (format "%s/\\([.0-9]+\\)" (regexp-quote name))
297 (match-string 1))))))
299 (defun auto-revert-vc-buffer-p ()
300 "Check if buffer is version controlled."
301 (and (boundp 'vc-mode)
302 (string-match "[0-9]" (or vc-mode ""))))
304 (defun auto-revert-handler-vc ()
305 "Check if version controlled buffer needs revert."
307 ;; 1. File is saved (*)
308 ;; 2. checkin is done 1.1 -> 1.2
309 ;; 3. VC reverts, so that updated version number is shown in mode line
311 ;; Suppose the same file has been opened in another Emacs and
312 ;; autorevert.el is on.
315 ;; 1. Step (1) is detected and buffer is reverted.
316 ;; 2. But check in does not always change the file in dis, but possibly only
317 ;; control files like CVS/Entries
318 ;; 3. The buffer is not reverted to update VC version line.
319 ;; Incorrect version number 1.1 is shown in this Emacs
322 (let* ((file (buffer-file-name))
323 (backend (vc-backend (buffer-file-name)))
324 (version-buffer (vc-workfile-version file)))
325 (when (stringp version-buffer)
329 (auto-revert-vc-cvs-file-version (buffer-file-name))))
330 (and (stringp version-file)
331 (not (string-match version-file version-buffer)))))
336 (defun auto-revert-handler ()
337 "Revert current buffer, if appropriate.
338 This is an internal function used by Auto-Revert Mode."
339 (unless (buffer-modified-p)
342 ((auto-revert-vc-buffer-p)
343 (when (auto-revert-handler-vc)
345 ((or (and (buffer-file-name)
346 (file-readable-p (buffer-file-name))
347 (not (verify-visited-file-modtime (current-buffer))))
348 (and (or auto-revert-mode global-auto-revert-non-file-buffers)
349 revert-buffer-function
350 (boundp 'buffer-stale-function)
351 (functionp buffer-stale-function)
352 (funcall buffer-stale-function t)))
355 (when auto-revert-verbose
356 (message "Reverting buffer `%s'." (buffer-name)))
357 (revert-buffer 'ignore-auto 'dont-ask 'preserve-modes)
358 ;; `preserve-modes' avoids changing the (minor) modes. But we
359 ;; do want to reset the mode for VC, so we do it explicitly.
362 (vc-mode-line buffer-file-name))))))
364 (defun auto-revert-buffers ()
365 "Revert buffers as specified by Auto-Revert and Global Auto-Revert Mode.
367 Should `global-auto-revert-mode' be active all file buffers are checked.
369 Should `auto-revert-mode' be active in some buffers, those buffers
372 Non-file buffers that have a custom `revert-buffer-function' and
373 a `buffer-stale-function' are reverted either when Auto-Revert
374 Mode is active in that buffer, or when the variable
375 `global-auto-revert-non-file-buffers' is non-nil and Global
376 Auto-Revert Mode is active.
378 This function stops whenever there is user input. The buffers not
379 checked are stored in the variable `auto-revert-remaining-buffers'.
381 To avoid starvation, the buffers in `auto-revert-remaining-buffers'
382 are checked first the next time this function is called.
384 This function is also responsible for removing buffers no longer in
385 Auto-Revert mode from `auto-revert-buffer-list', and for canceling
386 the timer when no buffers need to be checked."
387 (let ((bufs (if global-auto-revert-mode
389 auto-revert-buffer-list))
392 ;; Partition `bufs' into two halves depending on whether or not
393 ;; the buffers are in `auto-revert-remaining-buffers'. The two
394 ;; halves are then re-joined with the "remaining" buffers at the
396 (dolist (buf auto-revert-remaining-buffers)
398 (push buf remaining)))
400 (if (not (memq buf remaining))
402 (setq bufs (nreverse (nconc new remaining)))
404 (not (and auto-revert-stop-on-user-input
406 (let ((buf (car bufs)))
407 (if (buffer-name buf) ; Buffer still alive?
408 (with-current-buffer buf
409 ;; Test if someone has turned off Auto-Revert Mode in a
410 ;; non-standard way, for example by changing major mode.
411 (if (and (not auto-revert-mode)
412 (memq buf auto-revert-buffer-list))
413 (setq auto-revert-buffer-list
414 (delq buf auto-revert-buffer-list)))
415 (when (auto-revert-active-p) (auto-revert-handler)))
416 ;; Remove dead buffer from `auto-revert-buffer-list'.
417 (setq auto-revert-buffer-list
418 (delq buf auto-revert-buffer-list))))
419 (setq bufs (cdr bufs)))
420 (setq auto-revert-remaining-buffers bufs)
421 ;; Check if we should cancel the timer.
422 (when (and (not global-auto-revert-mode)
423 (null auto-revert-buffer-list))
424 (cancel-timer auto-revert-timer)
425 (setq auto-revert-timer nil))))
429 (provide 'autorevert)
431 (run-hooks 'auto-revert-load-hook)
433 ;;; arch-tag: f6bcb07b-4841-477e-9e44-b18678e58876
434 ;;; autorevert.el ends here