[bpt/emacs.git] / lisp / autorevert.el

;;; autorevert --- revert buffers when files on disk change

;; Copyright (C) 1997, 1998 Free Software Foundation, Inc.

;; Author: Anders Lindgren <andersl@csd.uu.se>
;; Keywords: convenience
;; Created: 1 Jun 1997
;; Date: 3 Jul 1997

;; 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
;; the Free Software Foundation; either version 2, or (at your option)
;; 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
;; 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.

;;; Commentary:

;; Introduction:
;;
;; Whenever a file that Emacs is editing has been changed by another
;; program the user normally has to execute the command `revert-buffer'
;; to load the new content of the file into Emacs.
;;
;; This package contains two minor modes: Global Auto-Revert Mode and
;; Auto-Revert Mode.  Both modes automatically revert buffers
;; whenever the corresponding files have been changed on disk.
;;
;; Auto-Revert Mode can be activated for individual buffers.
;; Global Auto-Revert Mode applies to all file buffers.
;;
;; Both modes operate by checking the time stamp of all files at
;; intervals of `auto-revert-interval'.  The default is every five
;; seconds.  The check is aborted whenever the user actually uses
;; Emacs.  You should never even notice that this package is active
;; (except that your buffers will be reverted, of course).

;; Usage:
;;
;; Go to the appropriate buffer and press:
;;   M-x auto-revert-mode RET
;;
;; To activate Global Auto-Revert Mode, press:
;;   M-x global-auto-revert-mode RET
;;
;; To activate Global Auto-Revert Mode every time Emacs is started
;; customise the option `global-auto-revert-mode' or the following
;; line could be added to your ~/.emacs:
;;   (global-auto-revert-mode 1)
;;
;; The function `turn-on-auto-revert-mode' could be added to any major
;; mode hook to activate Auto-Revert Mode for all buffers in that
;; mode.  For example, the following line will activate Auto-Revert
;; Mode in all C mode buffers:
;;
;; (add-hook 'c-mode-hook 'turn-on-auto-revert-mode)

;;; Code:

;; Dependencies:

(require 'timer)
(eval-when-compile (require 'cl))


;; Custom Group:
;;
;; The two modes will be placed next to Auto Save Mode under the
;; Files group under Emacs.

(defgroup auto-revert nil
  "Revert individual buffers when files on disk change.

Auto-Revert Mode can be activated for individual buffer.
Global Auto-Revert Mode applies to all buffers."
  :group 'files
  :group 'convenience)


;; Variables:

(defvar auto-revert-mode nil
  "*Non-nil when Auto-Revert Mode is active.

Never set this variable directly, use the command `auto-revert-mode'
instead.")

(defcustom global-auto-revert-mode nil
  "When on, buffers are automatically reverted when files on disk change.

Set this variable using \\[customize] only.  Otherwise, use the
command `global-auto-revert-mode'."
  :group 'auto-revert
  :initialize 'custom-initialize-default
  :set '(lambda (symbol value)
	  (global-auto-revert-mode (or value 0)))
  :type 'boolean
  :require 'autorevert)

(defcustom auto-revert-interval 5
  "Time, in seconds, between Auto-Revert Mode file checks."
  :group 'auto-revert
  :type 'integer)

(defcustom auto-revert-stop-on-user-input t
  "When non-nil Auto-Revert Mode stops checking files on user input."
  :group 'auto-revert
  :type 'boolean)

(defcustom auto-revert-verbose t
  "When nil, Auto-Revert Mode will not generate any messages.

Currently, messages are generated when the mode is activated or
deactivated, and whenever a file is reverted."
  :group 'auto-revert
  :type 'boolean)

(defcustom auto-revert-mode-text " ARev"
  "String to display in the mode line when Auto-Revert Mode is active.

\(When the string is not empty, make sure that it has a leading space.)"
  :tag "Auto Revert Mode Text"		; To separate it from `global-...'
  :group 'auto-revert
  :type 'string)

(defcustom auto-revert-mode-hook nil
  "Functions to run when Auto-Revert Mode is activated."
  :tag "Auto Revert Mode Hook"		; To separate it from `global-...'
  :group 'auto-revert
  :type 'hook)

(defcustom global-auto-revert-mode-text ""
  "String to display when Global Auto-Revert Mode is active.

The default is nothing since when this mode is active this text doesn't
vary over time, or between buffers.  Hence mode line text
would only waste precious space."
  :group 'auto-revert
  :type 'string)

(defcustom global-auto-revert-mode-hook nil
  "Hook called when Global Auto-Revert Mode is activated."
  :group 'auto-revert
  :type 'hook)

(defcustom global-auto-revert-non-file-buffers nil
  "*When nil only file buffers are reverted by Global Auto-Revert Mode.

When non-nil, both file buffers and buffers with a custom
`revert-buffer-function' are reverted by Global Auto-Revert Mode."
  :group 'auto-revert
  :type 'boolean)

(defcustom global-auto-revert-non-file-buffers nil
  "When nil only file buffers are reverted by Global Auto-Revert Mode.

When non-nil, both file buffers and buffers with a custom
`revert-buffer-function' are reverted by Global Auto-Revert Mode.

Use this option with care since it could lead to excessive reverts."
  :group 'auto-revert
  :type 'boolean)

(defcustom global-auto-revert-ignore-modes '()
  "List of major modes Global Auto-Revert Mode should not check."
  :group 'auto-revert
  :type '(repeat sexp))

(defcustom auto-revert-load-hook nil
  "Functions to run when Auto-Revert Mode is first loaded."
  :tag "Load Hook"
  :group 'auto-revert
  :type 'hook)

(defvar global-auto-revert-ignore-buffer nil
  "*When non-nil, Global Auto-Revert Mode will not revert this buffer.

This variable becomes buffer local when set in any fashion.")
(make-variable-buffer-local 'global-auto-revert-ignore-buffer)


;; Internal variables:

(defvar auto-revert-buffer-list '()
  "List of buffers in Auto-Revert Mode.

Note that only Auto-Revert Mode, never Global Auto-Revert Mode, adds
buffers to this list.

The timer function `auto-revert-buffers' is responsible for purging
the list of old buffers.")

(defvar auto-revert-timer nil
  "Timer used by Auto-Revert Mode.")

(defvar auto-revert-remaining-buffers '()
  "Buffers not checked when user input stopped execution.")


;; Functions:

;;;###autoload
(defun auto-revert-mode (&optional arg)
  "Toggle reverting buffer when file on disk changes.

With arg, turn Auto Revert mode on if and only if arg is positive.
This is a minor mode that affects only the current buffer.
Use `global-auto-revert-mode' to automatically revert all buffers."
  (interactive "P")
  (make-local-variable 'auto-revert-mode)
  (setq auto-revert-mode
	(if (null arg)
	    (not auto-revert-mode)
	  (> (prefix-numeric-value arg) 0)))
  (if (and auto-revert-verbose
	   (interactive-p))
      (message "Auto-Revert Mode is now %s."
	       (if auto-revert-mode "on" "off")))
  (if auto-revert-mode
      (if (not (memq (current-buffer) auto-revert-buffer-list))
	  (push (current-buffer) auto-revert-buffer-list))
    (setq auto-revert-buffer-list
	  (delq (current-buffer) auto-revert-buffer-list)))
  (auto-revert-set-timer)
  (when auto-revert-mode
    (auto-revert-buffers)
    (run-hooks 'auto-revert-mode-hook)))


;;;###autoload
(defun turn-on-auto-revert-mode ()
  "Turn on Auto-Revert Mode.

This function is designed to be added to hooks, for example:
  (add-hook 'c-mode-hook 'turn-on-auto-revert-mode)"
  (auto-revert-mode 1))


;;;###autoload
(defun global-auto-revert-mode (&optional arg)
  "Revert any buffer when file on disk change.

With arg, turn Auto Revert mode on globally if and only if arg is positive.
This is a minor mode that affects all buffers.
Use `auto-revert-mode' to revert a particular buffer."
  (interactive "P")
  (setq global-auto-revert-mode
	(if (null arg)
	    (not global-auto-revert-mode)
	  (> (prefix-numeric-value arg) 0)))
  (if (and auto-revert-verbose
	   (interactive-p))
      (message "Global Auto-Revert Mode is now %s."
	       (if global-auto-revert-mode "on" "off")))
  (auto-revert-set-timer)
  (when global-auto-revert-mode
    (auto-revert-buffers)      
    (run-hooks 'global-auto-revert-mode-hook)))


(defun auto-revert-set-timer ()
  "Restart or cancel the timer."
  (if (timerp auto-revert-timer)
      (cancel-timer auto-revert-timer))
  (if (or global-auto-revert-mode auto-revert-buffer-list)
      (setq auto-revert-timer (run-with-timer auto-revert-interval
					      auto-revert-interval
					      'auto-revert-buffers))
    (setq auto-revert-timer nil)))


(defun auto-revert-buffers ()
  "Revert buffers as specified by Auto-Revert and Global Auto-Revert Mode.

Should `global-auto-revert-mode' be active all file buffers are checked.

Should `auto-revert-mode' be active in some buffers, those buffers
are checked.

Non-file buffers that have a custom `revert-buffer-function' are
reverted either when Auto-Revert Mode is active in that buffer, or
when the variable `global-auto-revert-non-file-buffers' is non-nil
and Global Auto-Revert Mode is active.

This function stops whenever there is user input.  The buffers not
checked are stored in the variable `auto-revert-remaining-buffers'.

To avoid starvation, the buffers in `auto-revert-remaining-buffers'
are checked first the next time this function is called.

This function is also responsible for removing buffers no longer in
Auto-Revert mode from `auto-revert-buffer-list', and for canceling
the timer when no buffers need to be checked."
  (let ((bufs (if global-auto-revert-mode
		  (buffer-list)
		auto-revert-buffer-list))
	(remaining '())
	(new '()))
    ;; Partition `bufs' into two halves depending on whether or not
    ;; the buffers are in `auto-revert-remaining-buffers'.  The two
    ;; halves are then re-joined with the "remaining" buffers at the
    ;; head of the list.
    (dolist (buf auto-revert-remaining-buffers)
      (if (memq buf bufs)
	  (push buf remaining)))
    (dolist (buf bufs)
      (if (not (memq buf remaining))
	  (push buf new)))
    (setq bufs (nreverse (nconc new remaining)))
    (while (and bufs
		(not (and auto-revert-stop-on-user-input
			  (input-pending-p))))
      (let ((buf (car bufs)))
	(if (buffer-name buf)		; Buffer still alive?
	    (save-excursion
	      (set-buffer buf)
	      ;; Test if someone has turned off Auto-Revert Mode in a
	      ;; non-standard way, for example by changing major mode.
	      (if (and (not auto-revert-mode)
		       (memq buf auto-revert-buffer-list))
		  (setq auto-revert-buffer-list
			(delq buf auto-revert-buffer-list)))
	      (when (and
		     (or auto-revert-mode
			 (and
			  global-auto-revert-mode
			  (not global-auto-revert-ignore-buffer)
			  (not (memq major-mode
				     global-auto-revert-ignore-modes))))
		     (not (buffer-modified-p))
		     (if (buffer-file-name)
			 (and (file-readable-p (buffer-file-name))
			      (not (verify-visited-file-modtime buf)))
		       (and revert-buffer-function
			    (or (and global-auto-revert-mode
				     global-auto-revert-non-file-buffers)
				auto-revert-mode))))
		(if auto-revert-verbose
		    (message "Reverting buffer `%s'." buf))
		(revert-buffer t t)))
	  ;; Remove dead buffer from `auto-revert-buffer-list'.
	  (setq auto-revert-buffer-list
		(delq buf auto-revert-buffer-list))))
      (setq bufs (cdr bufs)))
    (setq auto-revert-remaining-buffers bufs)
    ;; Check if we should cancel the timer.
    (when (and (not global-auto-revert-mode)
	       (null auto-revert-buffer-list))
      (cancel-timer auto-revert-timer)
      (setq auto-revert-timer nil))))


;; The end:

(unless (assq 'auto-revert-mode minor-mode-alist)
  (push '(auto-revert-mode auto-revert-mode-text)
	minor-mode-alist))
(unless (assq 'global-auto-revert-mode minor-mode-alist)
  (push '(global-auto-revert-mode global-auto-revert-mode-text)
	minor-mode-alist))

(provide 'autorevert)

(run-hooks 'auto-revert-load-hook)

;; This makes it possible to set Global Auto-Revert Mode from
;; Customize.
(if global-auto-revert-mode
    (global-auto-revert-mode 1))

;; autorevert.el ends here.
Commit	Line	Data
5abdc915	1	;;; autorevert --- revert buffers when files on disk change
4a35aff3	2
48764ae2	3	;; Copyright (C) 1997, 1998 Free Software Foundation, Inc.
4a35aff3 RS	4
4a35aff3 RS	5	;; Author: Anders Lindgren <andersl@csd.uu.se>
f5f727f8	6	;; Keywords: convenience
4a35aff3 RS	7	;; Created: 1 Jun 1997
	8	;; Date: 3 Jul 1997
	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).
4a35aff3 RS	47
	48	;; Usage:
	49	;;
	50	;; Go to the appropriate buffer and press:
	51	;; M-x auto-revert-mode RET
	52	;;
	53	;; To activate Global Auto-Revert Mode, press:
	54	;; M-x global-auto-revert-mode RET
	55	;;
48764ae2 DL	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:
4a35aff3 RS	59	;; (global-auto-revert-mode 1)
	60	;;
	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:
	65	;;
	66	;; (add-hook 'c-mode-hook 'turn-on-auto-revert-mode)
	67
	68	;;; Code:
	69
	70	;; Dependencies:
	71
	72	(require 'timer)
	73	(eval-when-compile (require 'cl))
	74
	75
	76	;; Custom Group:
	77	;;
	78	;; The two modes will be placed next to Auto Save Mode under the
	79	;; Files group under Emacs.
	80
	81	(defgroup auto-revert nil
48764ae2	82	"Revert individual buffers when files on disk change.
4a35aff3 RS	83
	84	Auto-Revert Mode can be activated for individual buffer.
	85	Global Auto-Revert Mode applies to all buffers."
f5f727f8 DN	86	:group 'files
f5f727f8 DN	87	:group 'convenience)
4a35aff3 RS	88
	89
	90	;; Variables:
	91
	92	(defvar auto-revert-mode nil
	93	"*Non-nil when Auto-Revert Mode is active.
	94
48764ae2 DL	95	Never set this variable directly, use the command `auto-revert-mode'
48764ae2 DL	96	instead.")
4a35aff3 RS	97
	98	(defcustom global-auto-revert-mode nil
	99	"When on, buffers are automatically reverted when files on disk change.
	100
48764ae2 DL	101	Set this variable using \\[customize] only. Otherwise, use the
48764ae2 DL	102	command `global-auto-revert-mode'."
4a35aff3 RS	103	:group 'auto-revert
	104	:initialize 'custom-initialize-default
	105	:set '(lambda (symbol value)
	106	(global-auto-revert-mode (or value 0)))
	107	:type 'boolean
	108	:require 'autorevert)
	109
	110	(defcustom auto-revert-interval 5
	111	"Time, in seconds, between Auto-Revert Mode file checks."
	112	:group 'auto-revert
	113	:type 'integer)
	114
	115	(defcustom auto-revert-stop-on-user-input t
	116	"When non-nil Auto-Revert Mode stops checking files on user input."
	117	:group 'auto-revert
	118	:type 'boolean)
	119
	120	(defcustom auto-revert-verbose t
	121	"When nil, Auto-Revert Mode will not generate any messages.
	122
	123	Currently, messages are generated when the mode is activated or
	124	deactivated, and whenever a file is reverted."
	125	:group 'auto-revert
	126	:type 'boolean)
	127
	128	(defcustom auto-revert-mode-text " ARev"
	129	"String to display in the mode line when Auto-Revert Mode is active.
	130
	131	\(When the string is not empty, make sure that it has a leading space.)"
	132	:tag "Auto Revert Mode Text" ; To separate it from `global-...'
	133	:group 'auto-revert
	134	:type 'string)
	135
	136	(defcustom auto-revert-mode-hook nil
	137	"Functions to run when Auto-Revert Mode is activated."
	138	:tag "Auto Revert Mode Hook" ; To separate it from `global-...'
	139	:group 'auto-revert
	140	:type 'hook)
	141
	142	(defcustom global-auto-revert-mode-text ""
	143	"String to display when Global Auto-Revert Mode is active.
	144
	145	The default is nothing since when this mode is active this text doesn't
48764ae2	146	vary over time, or between buffers. Hence mode line text
4a35aff3 RS	147	would only waste precious space."
	148	:group 'auto-revert
	149	:type 'string)
	150
	151	(defcustom global-auto-revert-mode-hook nil
	152	"Hook called when Global Auto-Revert Mode is activated."
	153	:group 'auto-revert
	154	:type 'hook)
	155
	156	(defcustom global-auto-revert-non-file-buffers nil
	157	"*When nil only file buffers are reverted by Global Auto-Revert Mode.
	158
	159	When non-nil, both file buffers and buffers with a custom
	160	`revert-buffer-function' are reverted by Global Auto-Revert Mode."
	161	:group 'auto-revert
	162	:type 'boolean)
	163
	164	(defcustom global-auto-revert-non-file-buffers nil
	165	"When nil only file buffers are reverted by Global Auto-Revert Mode.
	166
	167	When non-nil, both file buffers and buffers with a custom
	168	`revert-buffer-function' are reverted by Global Auto-Revert Mode.
	169
	170	Use this option with care since it could lead to excessive reverts."
	171	:group 'auto-revert
	172	:type 'boolean)
	173
	174	(defcustom global-auto-revert-ignore-modes '()
	175	"List of major modes Global Auto-Revert Mode should not check."
	176	:group 'auto-revert
	177	:type '(repeat sexp))
	178
	179	(defcustom auto-revert-load-hook nil
	180	"Functions to run when Auto-Revert Mode is first loaded."
	181	:tag "Load Hook"
	182	:group 'auto-revert
	183	:type 'hook)
	184
	185	(defvar global-auto-revert-ignore-buffer nil
f1e3ff80	186	"*When non-nil, Global Auto-Revert Mode will not revert this buffer.
4a35aff3	187
48764ae2	188	This variable becomes buffer local when set in any fashion.")
4a35aff3 RS	189	(make-variable-buffer-local 'global-auto-revert-ignore-buffer)
	190
	191
	192	;; Internal variables:
	193
	194	(defvar auto-revert-buffer-list '()
	195	"List of buffers in Auto-Revert Mode.
	196
	197	Note that only Auto-Revert Mode, never Global Auto-Revert Mode, adds
	198	buffers to this list.
	199
	200	The timer function `auto-revert-buffers' is responsible for purging
	201	the list of old buffers.")
	202
	203	(defvar auto-revert-timer nil
	204	"Timer used by Auto-Revert Mode.")
	205
	206	(defvar auto-revert-remaining-buffers '()
	207	"Buffers not checked when user input stopped execution.")
	208
	209
	210	;; Functions:
	211
	212	;;;###autoload
	213	(defun auto-revert-mode (&optional arg)
48764ae2	214	"Toggle reverting buffer when file on disk changes.
4a35aff3	215
48764ae2 DL	216	With arg, turn Auto Revert mode on if and only if arg is positive.
48764ae2 DL	217	This is a minor mode that affects only the current buffer.
4a35aff3 RS	218	Use `global-auto-revert-mode' to automatically revert all buffers."
	219	(interactive "P")
	220	(make-local-variable 'auto-revert-mode)
	221	(setq auto-revert-mode
	222	(if (null arg)
	223	(not auto-revert-mode)
	224	(> (prefix-numeric-value arg) 0)))
	225	(if (and auto-revert-verbose
	226	(interactive-p))
	227	(message "Auto-Revert Mode is now %s."
	228	(if auto-revert-mode "on" "off")))
	229	(if auto-revert-mode
	230	(if (not (memq (current-buffer) auto-revert-buffer-list))
	231	(push (current-buffer) auto-revert-buffer-list))
	232	(setq auto-revert-buffer-list
	233	(delq (current-buffer) auto-revert-buffer-list)))
	234	(auto-revert-set-timer)
	235	(when auto-revert-mode
	236	(auto-revert-buffers)
	237	(run-hooks 'auto-revert-mode-hook)))
	238
	239
	240	;;;###autoload
	241	(defun turn-on-auto-revert-mode ()
	242	"Turn on Auto-Revert Mode.
	243
	244	This function is designed to be added to hooks, for example:
	245	(add-hook 'c-mode-hook 'turn-on-auto-revert-mode)"
	246	(auto-revert-mode 1))
	247
	248
	249	;;;###autoload
	250	(defun global-auto-revert-mode (&optional arg)
	251	"Revert any buffer when file on disk change.
	252
48764ae2 DL	253	With arg, turn Auto Revert mode on globally if and only if arg is positive.
48764ae2 DL	254	This is a minor mode that affects all buffers.
4a35aff3 RS	255	Use `auto-revert-mode' to revert a particular buffer."
	256	(interactive "P")
	257	(setq global-auto-revert-mode
	258	(if (null arg)
	259	(not global-auto-revert-mode)
	260	(> (prefix-numeric-value arg) 0)))
	261	(if (and auto-revert-verbose
	262	(interactive-p))
f1e3ff80	263	(message "Global Auto-Revert Mode is now %s."
4a35aff3 RS	264	(if global-auto-revert-mode "on" "off")))
	265	(auto-revert-set-timer)
	266	(when global-auto-revert-mode
	267	(auto-revert-buffers)
	268	(run-hooks 'global-auto-revert-mode-hook)))
	269
	270
	271	(defun auto-revert-set-timer ()
	272	"Restart or cancel the timer."
	273	(if (timerp auto-revert-timer)
	274	(cancel-timer auto-revert-timer))
	275	(if (or global-auto-revert-mode auto-revert-buffer-list)
	276	(setq auto-revert-timer (run-with-timer auto-revert-interval
	277	auto-revert-interval
	278	'auto-revert-buffers))
	279	(setq auto-revert-timer nil)))
	280
	281
	282	(defun auto-revert-buffers ()
	283	"Revert buffers as specified by Auto-Revert and Global Auto-Revert Mode.
	284
	285	Should `global-auto-revert-mode' be active all file buffers are checked.
	286
	287	Should `auto-revert-mode' be active in some buffers, those buffers
	288	are checked.
	289
	290	Non-file buffers that have a custom `revert-buffer-function' are
	291	reverted either when Auto-Revert Mode is active in that buffer, or
	292	when the variable `global-auto-revert-non-file-buffers' is non-nil
	293	and Global Auto-Revert Mode is active.
	294
48764ae2	295	This function stops whenever there is user input. The buffers not
4a35aff3 RS	296	checked are stored in the variable `auto-revert-remaining-buffers'.
	297
	298	To avoid starvation, the buffers in `auto-revert-remaining-buffers'
	299	are checked first the next time this function is called.
	300
48764ae2	301	This function is also responsible for removing buffers no longer in
4a35aff3 RS	302	Auto-Revert mode from `auto-revert-buffer-list', and for canceling
	303	the timer when no buffers need to be checked."
	304	(let ((bufs (if global-auto-revert-mode
	305	(buffer-list)
	306	auto-revert-buffer-list))
	307	(remaining '())
	308	(new '()))
	309	;; Partition `bufs' into two halves depending on whether or not
	310	;; the buffers are in `auto-revert-remaining-buffers'. The two
	311	;; halves are then re-joined with the "remaining" buffers at the
	312	;; head of the list.
	313	(dolist (buf auto-revert-remaining-buffers)
	314	(if (memq buf bufs)
	315	(push buf remaining)))
	316	(dolist (buf bufs)
	317	(if (not (memq buf remaining))
	318	(push buf new)))
	319	(setq bufs (nreverse (nconc new remaining)))
	320	(while (and bufs
	321	(not (and auto-revert-stop-on-user-input
	322	(input-pending-p))))
	323	(let ((buf (car bufs)))
	324	(if (buffer-name buf) ; Buffer still alive?
	325	(save-excursion
	326	(set-buffer buf)
	327	;; Test if someone has turned off Auto-Revert Mode in a
	328	;; non-standard way, for example by changing major mode.
	329	(if (and (not auto-revert-mode)
	330	(memq buf auto-revert-buffer-list))
	331	(setq auto-revert-buffer-list
	332	(delq buf auto-revert-buffer-list)))
	333	(when (and
	334	(or auto-revert-mode
	335	(and
	336	global-auto-revert-mode
	337	(not global-auto-revert-ignore-buffer)
	338	(not (memq major-mode
	339	global-auto-revert-ignore-modes))))
	340	(not (buffer-modified-p))
	341	(if (buffer-file-name)
	342	(and (file-readable-p (buffer-file-name))
	343	(not (verify-visited-file-modtime buf)))
	344	(and revert-buffer-function
	345	(or (and global-auto-revert-mode
	346	global-auto-revert-non-file-buffers)
	347	auto-revert-mode))))
	348	(if auto-revert-verbose
	349	(message "Reverting buffer `%s'." buf))
	350	(revert-buffer t t)))
	351	;; Remove dead buffer from `auto-revert-buffer-list'.
	352	(setq auto-revert-buffer-list
	353	(delq buf auto-revert-buffer-list))))
	354	(setq bufs (cdr bufs)))
	355	(setq auto-revert-remaining-buffers bufs)
	356	;; Check if we should cancel the timer.
	357	(when (and (not global-auto-revert-mode)
	358	(null auto-revert-buffer-list))
	359	(cancel-timer auto-revert-timer)
	360	(setq auto-revert-timer nil))))
	361
	362
	363	;; The end:
	364
	365	(unless (assq 'auto-revert-mode minor-mode-alist)
366	(push '(auto-revert-mode auto-revert-mode-text)
367	minor-mode-alist))
368	(unless (assq 'global-auto-revert-mode minor-mode-alist)
369	(push '(global-auto-revert-mode global-auto-revert-mode-text)
370	minor-mode-alist))
371
372	(provide 'autorevert)
373
374	(run-hooks 'auto-revert-load-hook)
375
376	;; This makes it possible to set Global Auto-Revert Mode from
377	;; Customize.
378	(if global-auto-revert-mode
379	(global-auto-revert-mode 1))
380
381	;; autorevert.el ends here.