Commit | Line | Data |
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e8af40ee | 1 | ;;; autorevert.el --- revert buffers when files on disk change |
4a35aff3 | 2 | |
bf2150fa | 3 | ;; Copyright (C) 1997, 1998, 1999, 2001 Free Software Foundation, Inc. |
4a35aff3 | 4 | |
a468671a | 5 | ;; Author: Anders Lindgren <andersl@andersl.com> |
f5f727f8 | 6 | ;; Keywords: convenience |
a468671a GM |
7 | ;; Created: 1997-06-01 |
8 | ;; Date: 1999-11-30 | |
4a35aff3 RS |
9 | |
10 | ;; This file is part of GNU Emacs. | |
11 | ||
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) | |
15 | ;; any later version. | |
16 | ||
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. | |
21 | ||
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. | |
26 | ||
27 | ;;; Commentary: | |
28 | ||
29 | ;; Introduction: | |
30 | ;; | |
31 | ;; Whenever a file that Emacs is editing has been changed by another | |
48764ae2 | 32 | ;; program the user normally has to execute the command `revert-buffer' |
4a35aff3 RS |
33 | ;; to load the new content of the file into Emacs. |
34 | ;; | |
35 | ;; This package contains two minor modes: Global Auto-Revert Mode and | |
48764ae2 | 36 | ;; Auto-Revert Mode. Both modes automatically revert buffers |
4a35aff3 RS |
37 | ;; whenever the corresponding files have been changed on disk. |
38 | ;; | |
39 | ;; Auto-Revert Mode can be activated for individual buffers. | |
40 | ;; Global Auto-Revert Mode applies to all file buffers. | |
41 | ;; | |
48764ae2 DL |
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). | |
1f41bcba LT |
47 | ;; |
48 | ;; After reverting a file buffer, Auto Revert Mode normally puts point | |
49 | ;; at the same position that a regular manual revert would. However, | |
50 | ;; there is one exception to this rule. If point is at the end of the | |
51 | ;; buffer before reverting, it stays at the end. Similarly if point | |
52 | ;; is displayed at the end of a file buffer in any window, it will stay | |
53 | ;; at the end of the buffer in that window, even if the window is not | |
54 | ;; selected. This way, you can use Auto Revert Mode to `tail' a file. | |
55 | ;; Just put point at the end of the buffer and it will stay there. | |
56 | ;; These rules apply to file buffers. For non-file buffers, the | |
57 | ;; behavior may be mode dependent. | |
4a35aff3 RS |
58 | |
59 | ;; Usage: | |
60 | ;; | |
61 | ;; Go to the appropriate buffer and press: | |
62 | ;; M-x auto-revert-mode RET | |
63 | ;; | |
64 | ;; To activate Global Auto-Revert Mode, press: | |
65 | ;; M-x global-auto-revert-mode RET | |
66 | ;; | |
48764ae2 DL |
67 | ;; To activate Global Auto-Revert Mode every time Emacs is started |
68 | ;; customise the option `global-auto-revert-mode' or the following | |
69 | ;; line could be added to your ~/.emacs: | |
4a35aff3 RS |
70 | ;; (global-auto-revert-mode 1) |
71 | ;; | |
72 | ;; The function `turn-on-auto-revert-mode' could be added to any major | |
73 | ;; mode hook to activate Auto-Revert Mode for all buffers in that | |
74 | ;; mode. For example, the following line will activate Auto-Revert | |
75 | ;; Mode in all C mode buffers: | |
76 | ;; | |
77 | ;; (add-hook 'c-mode-hook 'turn-on-auto-revert-mode) | |
78 | ||
79 | ;;; Code: | |
80 | ||
81 | ;; Dependencies: | |
82 | ||
83 | (require 'timer) | |
0f98bc23 | 84 | |
71c8db4c | 85 | (eval-when-compile (require 'cl)) |
4a35aff3 RS |
86 | |
87 | ||
88 | ;; Custom Group: | |
89 | ;; | |
90 | ;; The two modes will be placed next to Auto Save Mode under the | |
91 | ;; Files group under Emacs. | |
92 | ||
93 | (defgroup auto-revert nil | |
48764ae2 | 94 | "Revert individual buffers when files on disk change. |
4a35aff3 RS |
95 | |
96 | Auto-Revert Mode can be activated for individual buffer. | |
97 | Global Auto-Revert Mode applies to all buffers." | |
f5f727f8 DN |
98 | :group 'files |
99 | :group 'convenience) | |
4a35aff3 RS |
100 | |
101 | ||
102 | ;; Variables: | |
103 | ||
00d0fda8 DL |
104 | ;; Autoload for the benefit of `make-mode-line-mouse-sensitive'. |
105 | ;;;###autoload | |
4a35aff3 RS |
106 | (defvar auto-revert-mode nil |
107 | "*Non-nil when Auto-Revert Mode is active. | |
0e4f9468 SM |
108 | Never set this variable directly, use the command `auto-revert-mode' instead.") |
109 | (put 'auto-revert-mode 'permanent-local t) | |
4a35aff3 | 110 | |
a2ac68f1 LT |
111 | (defvar auto-revert-timer nil |
112 | "Timer used by Auto-Revert Mode.") | |
113 | ||
4a35aff3 | 114 | (defcustom auto-revert-interval 5 |
ad660075 | 115 | "Time, in seconds, between Auto-Revert Mode file checks. |
a2ac68f1 LT |
116 | The value may be an integer or floating point number. |
117 | ||
118 | If a timer is already active, there are two ways to make sure | |
119 | that the new value will take effect immediately. You can set | |
120 | this variable through Custom or you can call the command | |
121 | `auto-revert-set-timer' after setting the variable. Otherwise, | |
122 | the new value will take effect the first time Auto Revert Mode | |
123 | calls `auto-revert-set-timer' for internal reasons or in your | |
124 | next editing session." | |
4a35aff3 | 125 | :group 'auto-revert |
a2ac68f1 LT |
126 | :type 'number |
127 | :set (lambda (variable value) | |
128 | (set-default variable value) | |
129 | (and (boundp 'auto-revert-timer) | |
130 | auto-revert-timer | |
131 | (auto-revert-set-timer)))) | |
4a35aff3 RS |
132 | |
133 | (defcustom auto-revert-stop-on-user-input t | |
134 | "When non-nil Auto-Revert Mode stops checking files on user input." | |
135 | :group 'auto-revert | |
136 | :type 'boolean) | |
137 | ||
138 | (defcustom auto-revert-verbose t | |
139 | "When nil, Auto-Revert Mode will not generate any messages. | |
0e5dcfd7 | 140 | When non-nil, a message is generated whenever a file is reverted." |
4a35aff3 RS |
141 | :group 'auto-revert |
142 | :type 'boolean) | |
143 | ||
144 | (defcustom auto-revert-mode-text " ARev" | |
145 | "String to display in the mode line when Auto-Revert Mode is active. | |
146 | ||
147 | \(When the string is not empty, make sure that it has a leading space.)" | |
148 | :tag "Auto Revert Mode Text" ; To separate it from `global-...' | |
149 | :group 'auto-revert | |
150 | :type 'string) | |
151 | ||
152 | (defcustom auto-revert-mode-hook nil | |
153 | "Functions to run when Auto-Revert Mode is activated." | |
154 | :tag "Auto Revert Mode Hook" ; To separate it from `global-...' | |
155 | :group 'auto-revert | |
156 | :type 'hook) | |
157 | ||
158 | (defcustom global-auto-revert-mode-text "" | |
159 | "String to display when Global Auto-Revert Mode is active. | |
160 | ||
161 | The default is nothing since when this mode is active this text doesn't | |
48764ae2 | 162 | vary over time, or between buffers. Hence mode line text |
4a35aff3 RS |
163 | would only waste precious space." |
164 | :group 'auto-revert | |
165 | :type 'string) | |
166 | ||
167 | (defcustom global-auto-revert-mode-hook nil | |
168 | "Hook called when Global Auto-Revert Mode is activated." | |
169 | :group 'auto-revert | |
170 | :type 'hook) | |
171 | ||
172 | (defcustom global-auto-revert-non-file-buffers nil | |
0e4f9468 | 173 | "When nil only file buffers are reverted by Global Auto-Revert Mode. |
4a35aff3 RS |
174 | |
175 | When non-nil, both file buffers and buffers with a custom | |
0e5dcfd7 LT |
176 | `revert-buffer-function' and a `buffer-stale-function' are |
177 | reverted by Global Auto-Revert Mode. | |
0e4f9468 | 178 | |
d4411cef LT |
179 | Use this option with care since it could lead to excessive reverts. |
180 | Note also that for some non-file buffers the check whether the | |
181 | buffer needs updating may be imperfect, due to efficiency | |
182 | considerations, and may not take all information listed in the | |
183 | buffer into account. Hence, a non-nil value for this option does | |
184 | not necessarily make manual updates useless for non-file buffers." | |
4a35aff3 RS |
185 | :group 'auto-revert |
186 | :type 'boolean) | |
187 | ||
4a35aff3 RS |
188 | (defcustom global-auto-revert-ignore-modes '() |
189 | "List of major modes Global Auto-Revert Mode should not check." | |
190 | :group 'auto-revert | |
191 | :type '(repeat sexp)) | |
192 | ||
193 | (defcustom auto-revert-load-hook nil | |
194 | "Functions to run when Auto-Revert Mode is first loaded." | |
195 | :tag "Load Hook" | |
196 | :group 'auto-revert | |
197 | :type 'hook) | |
198 | ||
71c8db4c LT |
199 | (defcustom auto-revert-check-vc-info nil |
200 | "If non-nil Auto Revert Mode reliably updates version control info. | |
201 | Auto Revert Mode updates version control info whenever the buffer | |
202 | needs reverting, regardless of the value of this variable. | |
203 | However, the version control state can change without changes to | |
204 | the work file. If the change is made from the current Emacs | |
205 | session, all info is updated. But if, for instance, a new | |
206 | version is checked in from outside the current Emacs session, the | |
207 | version control number in the mode line, as well as other version | |
208 | control related information, may not be properly updated. If you | |
209 | are worried about this, set this variable to a non-nil value. | |
210 | ||
211 | This currently works by automatically updating the version | |
212 | control info every `auto-revert-interval' seconds. Nevertheless, | |
213 | it should not cause excessive CPU usage on a reasonably fast | |
214 | machine, if it does not apply to too many version controlled | |
215 | buffers. CPU usage depends on the version control system" | |
216 | :group 'auto-revert | |
217 | :type 'boolean | |
218 | :version "21.4") | |
219 | ||
4a35aff3 | 220 | (defvar global-auto-revert-ignore-buffer nil |
f1e3ff80 | 221 | "*When non-nil, Global Auto-Revert Mode will not revert this buffer. |
4a35aff3 | 222 | |
48764ae2 | 223 | This variable becomes buffer local when set in any fashion.") |
4a35aff3 RS |
224 | (make-variable-buffer-local 'global-auto-revert-ignore-buffer) |
225 | ||
4a35aff3 RS |
226 | ;; Internal variables: |
227 | ||
228 | (defvar auto-revert-buffer-list '() | |
229 | "List of buffers in Auto-Revert Mode. | |
230 | ||
231 | Note that only Auto-Revert Mode, never Global Auto-Revert Mode, adds | |
232 | buffers to this list. | |
233 | ||
234 | The timer function `auto-revert-buffers' is responsible for purging | |
235 | the list of old buffers.") | |
236 | ||
4a35aff3 RS |
237 | (defvar auto-revert-remaining-buffers '() |
238 | "Buffers not checked when user input stopped execution.") | |
239 | ||
240 | ||
241 | ;; Functions: | |
242 | ||
243 | ;;;###autoload | |
0e4f9468 | 244 | (define-minor-mode auto-revert-mode |
48764ae2 | 245 | "Toggle reverting buffer when file on disk changes. |
4a35aff3 | 246 | |
48764ae2 DL |
247 | With arg, turn Auto Revert mode on if and only if arg is positive. |
248 | This is a minor mode that affects only the current buffer. | |
4a35aff3 | 249 | Use `global-auto-revert-mode' to automatically revert all buffers." |
0e4f9468 | 250 | nil auto-revert-mode-text nil |
4a35aff3 RS |
251 | (if auto-revert-mode |
252 | (if (not (memq (current-buffer) auto-revert-buffer-list)) | |
253 | (push (current-buffer) auto-revert-buffer-list)) | |
254 | (setq auto-revert-buffer-list | |
255 | (delq (current-buffer) auto-revert-buffer-list))) | |
256 | (auto-revert-set-timer) | |
257 | (when auto-revert-mode | |
0e4f9468 | 258 | (auto-revert-buffers))) |
4a35aff3 RS |
259 | |
260 | ||
261 | ;;;###autoload | |
262 | (defun turn-on-auto-revert-mode () | |
263 | "Turn on Auto-Revert Mode. | |
264 | ||
265 | This function is designed to be added to hooks, for example: | |
266 | (add-hook 'c-mode-hook 'turn-on-auto-revert-mode)" | |
267 | (auto-revert-mode 1)) | |
268 | ||
269 | ||
270 | ;;;###autoload | |
0e4f9468 | 271 | (define-minor-mode global-auto-revert-mode |
0e5dcfd7 | 272 | "Revert any buffer when file on disk changes. |
4a35aff3 | 273 | |
48764ae2 DL |
274 | With arg, turn Auto Revert mode on globally if and only if arg is positive. |
275 | This is a minor mode that affects all buffers. | |
4a35aff3 | 276 | Use `auto-revert-mode' to revert a particular buffer." |
0e4f9468 | 277 | :global t :group 'auto-revert :lighter global-auto-revert-mode-text |
4a35aff3 RS |
278 | (auto-revert-set-timer) |
279 | (when global-auto-revert-mode | |
0e4f9468 | 280 | (auto-revert-buffers))) |
4a35aff3 RS |
281 | |
282 | ||
283 | (defun auto-revert-set-timer () | |
0e5dcfd7 | 284 | "Restart or cancel the timer used by Auto-Revert Mode. |
d97c8375 | 285 | If such a timer is active, cancel it. Start a new timer if |
0e5dcfd7 LT |
286 | Global Auto-Revert Mode is active or if Auto-Revert Mode is active |
287 | in some buffer. Restarting the timer ensures that Auto-Revert Mode | |
288 | will use an up-to-date value of `auto-revert-interval'" | |
a2ac68f1 | 289 | (interactive) |
4a35aff3 RS |
290 | (if (timerp auto-revert-timer) |
291 | (cancel-timer auto-revert-timer)) | |
0e4f9468 SM |
292 | (setq auto-revert-timer |
293 | (if (or global-auto-revert-mode auto-revert-buffer-list) | |
294 | (run-with-timer auto-revert-interval | |
295 | auto-revert-interval | |
296 | 'auto-revert-buffers) | |
297 | nil))) | |
4a35aff3 | 298 | |
ed35db71 EZ |
299 | (defun auto-revert-active-p () |
300 | "Check if auto-revert is active (in current buffer or globally)." | |
301 | (or auto-revert-mode | |
302 | (and | |
303 | global-auto-revert-mode | |
304 | (not global-auto-revert-ignore-buffer) | |
305 | (not (memq major-mode | |
306 | global-auto-revert-ignore-modes))))) | |
307 | ||
ed35db71 | 308 | (defun auto-revert-handler () |
0e5dcfd7 LT |
309 | "Revert current buffer, if appropriate. |
310 | This is an internal function used by Auto-Revert Mode." | |
d4411cef | 311 | (unless (buffer-modified-p) |
1f41bcba LT |
312 | (let ((buffer (current-buffer)) revert eob eoblist) |
313 | (or (and buffer-file-name | |
e7893b53 | 314 | (not (file-remote-p buffer-file-name)) |
1f41bcba LT |
315 | (file-readable-p buffer-file-name) |
316 | (not (verify-visited-file-modtime buffer)) | |
71c8db4c LT |
317 | (setq revert t)) |
318 | (and (or auto-revert-mode global-auto-revert-non-file-buffers) | |
319 | revert-buffer-function | |
320 | (boundp 'buffer-stale-function) | |
321 | (functionp buffer-stale-function) | |
322 | (setq revert (funcall buffer-stale-function t)))) | |
d4411cef | 323 | (when revert |
71c8db4c LT |
324 | (when (and auto-revert-verbose |
325 | (not (eq revert 'fast))) | |
633e0363 | 326 | (message "Reverting buffer `%s'." (buffer-name))) |
1f41bcba LT |
327 | ;; If point (or a window point) is at the end of the buffer, |
328 | ;; we want to keep it at the end after reverting. This allows | |
329 | ;; to tail a file. | |
330 | (when buffer-file-name | |
331 | (setq eob (eobp)) | |
332 | (walk-windows | |
333 | #'(lambda (window) | |
334 | (and (eq (window-buffer window) buffer) | |
335 | (= (window-point window) (point-max)) | |
336 | (push window eoblist))) | |
337 | 'no-mini t)) | |
338 | (revert-buffer 'ignore-auto 'dont-ask 'preserve-modes) | |
339 | (when buffer-file-name | |
340 | (when eob (goto-char (point-max))) | |
341 | (dolist (window eoblist) | |
342 | (set-window-point window (point-max))))) | |
71c8db4c LT |
343 | ;; `preserve-modes' avoids changing the (minor) modes. But we |
344 | ;; do want to reset the mode for VC, so we do it manually. | |
345 | (when (or revert auto-revert-check-vc-info) | |
346 | (vc-find-file-hook))))) | |
ed35db71 | 347 | |
4a35aff3 RS |
348 | (defun auto-revert-buffers () |
349 | "Revert buffers as specified by Auto-Revert and Global Auto-Revert Mode. | |
350 | ||
351 | Should `global-auto-revert-mode' be active all file buffers are checked. | |
352 | ||
353 | Should `auto-revert-mode' be active in some buffers, those buffers | |
354 | are checked. | |
355 | ||
0e5dcfd7 LT |
356 | Non-file buffers that have a custom `revert-buffer-function' and |
357 | a `buffer-stale-function' are reverted either when Auto-Revert | |
358 | Mode is active in that buffer, or when the variable | |
359 | `global-auto-revert-non-file-buffers' is non-nil and Global | |
360 | Auto-Revert Mode is active. | |
4a35aff3 | 361 | |
48764ae2 | 362 | This function stops whenever there is user input. The buffers not |
4a35aff3 RS |
363 | checked are stored in the variable `auto-revert-remaining-buffers'. |
364 | ||
365 | To avoid starvation, the buffers in `auto-revert-remaining-buffers' | |
366 | are checked first the next time this function is called. | |
367 | ||
48764ae2 | 368 | This function is also responsible for removing buffers no longer in |
4a35aff3 RS |
369 | Auto-Revert mode from `auto-revert-buffer-list', and for canceling |
370 | the timer when no buffers need to be checked." | |
371 | (let ((bufs (if global-auto-revert-mode | |
372 | (buffer-list) | |
373 | auto-revert-buffer-list)) | |
374 | (remaining '()) | |
375 | (new '())) | |
376 | ;; Partition `bufs' into two halves depending on whether or not | |
377 | ;; the buffers are in `auto-revert-remaining-buffers'. The two | |
378 | ;; halves are then re-joined with the "remaining" buffers at the | |
379 | ;; head of the list. | |
380 | (dolist (buf auto-revert-remaining-buffers) | |
381 | (if (memq buf bufs) | |
382 | (push buf remaining))) | |
383 | (dolist (buf bufs) | |
384 | (if (not (memq buf remaining)) | |
385 | (push buf new))) | |
386 | (setq bufs (nreverse (nconc new remaining))) | |
387 | (while (and bufs | |
388 | (not (and auto-revert-stop-on-user-input | |
389 | (input-pending-p)))) | |
390 | (let ((buf (car bufs))) | |
391 | (if (buffer-name buf) ; Buffer still alive? | |
0e4f9468 | 392 | (with-current-buffer buf |
4a35aff3 RS |
393 | ;; Test if someone has turned off Auto-Revert Mode in a |
394 | ;; non-standard way, for example by changing major mode. | |
395 | (if (and (not auto-revert-mode) | |
396 | (memq buf auto-revert-buffer-list)) | |
397 | (setq auto-revert-buffer-list | |
398 | (delq buf auto-revert-buffer-list))) | |
c86afc19 | 399 | (when (auto-revert-active-p) (auto-revert-handler))) |
4a35aff3 RS |
400 | ;; Remove dead buffer from `auto-revert-buffer-list'. |
401 | (setq auto-revert-buffer-list | |
402 | (delq buf auto-revert-buffer-list)))) | |
403 | (setq bufs (cdr bufs))) | |
404 | (setq auto-revert-remaining-buffers bufs) | |
405 | ;; Check if we should cancel the timer. | |
406 | (when (and (not global-auto-revert-mode) | |
407 | (null auto-revert-buffer-list)) | |
408 | (cancel-timer auto-revert-timer) | |
409 | (setq auto-revert-timer nil)))) | |
410 | ||
411 | ||
412 | ;; The end: | |
4a35aff3 RS |
413 | (provide 'autorevert) |
414 | ||
415 | (run-hooks 'auto-revert-load-hook) | |
416 | ||
ab5796a9 | 417 | ;;; arch-tag: f6bcb07b-4841-477e-9e44-b18678e58876 |
e8af40ee | 418 | ;;; autorevert.el ends here |