-;; autorevert --- Revert buffers when file on disk change.
+;;; autorevert.el --- revert buffers when files on disk change
-;; Copyright (C) 1997, 1998 Free Software Foundation, Inc.
+;; Copyright (C) 1997, 1998, 1999, 2001, 2002, 2003, 2004,
+;; 2005, 2006 Free Software Foundation, Inc.
-;; Author: Anders Lindgren <andersl@csd.uu.se>
-;; Created: 1 Jun 1997
-;; Date: 3 Jul 1997
+;; Author: Anders Lindgren <andersl@andersl.com>
+;; Keywords: convenience
+;; Created: 1997-06-01
+;; Date: 1999-11-30
;; This file is part of GNU Emacs.
;; 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.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
;;
;; 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.
+;; whenever the corresponding files have been changed on disk and the
+;; buffer contains no unsaved changes.
;;
-;; Auto-Revert Mode can be activated for individual buffers.
-;; Global Auto-Revert Mode applies to all file buffers.
+;; Auto-Revert Mode can be activated for individual buffers. Global
+;; Auto-Revert Mode applies to all file buffers. (If the user option
+;; `global-auto-revert-non-file-buffers' is non-nil, it also applies
+;; to some non-file buffers. This option is disabled by default.)
+;; Since checking a remote file is too slow, these modes do not check
+;; or revert remote files.
;;
;; 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).
+;;
+;; After reverting a file buffer, Auto Revert Mode normally puts point
+;; at the same position that a regular manual revert would. However,
+;; there is one exception to this rule. If point is at the end of the
+;; buffer before reverting, it stays at the end. Similarly if point
+;; is displayed at the end of a file buffer in any window, it will stay
+;; at the end of the buffer in that window, even if the window is not
+;; selected. This way, you can use Auto Revert Mode to `tail' a file.
+;; Just put point at the end of the buffer and it will stay there.
+;; These rules apply to file buffers. For non-file buffers, the
+;; behavior may be mode dependent.
+;;
+;; While you can use Auto Revert Mode to tail a file, this package
+;; contains a third minor mode, Auto Revert Tail Mode, which does so
+;; more efficiently, as long as you are sure that the file will only
+;; change by growing at the end. It only appends the new output,
+;; instead of reverting the entire buffer. It does so even if the
+;; buffer contains unsaved changes. (Because they will not be lost.)
;; Usage:
;;
-;; Go to the appropriate buffer and press:
+;; Go to the appropriate buffer and press either of:
;; M-x auto-revert-mode RET
+;; M-x auto-revert-tail-mode RET
;;
;; To activate Global Auto-Revert Mode, press:
;; M-x global-auto-revert-mode RET
;; Dependencies:
(require 'timer)
+
(eval-when-compile (require 'cl))
Auto-Revert Mode can be activated for individual buffer.
Global Auto-Revert Mode applies to all buffers."
- :group 'files)
+ :group 'files
+ :group 'convenience)
;; Variables:
+;;; What's this?: ;; Autoload for the benefit of `make-mode-line-mouse-sensitive'.
+;;; What's this?: ;;;###autoload
(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.")
+(put 'auto-revert-mode 'permanent-local t)
-Never set this variable directly, use the command `auto-revert-mode'
-instead.")
+(defvar auto-revert-tail-mode nil
+ "*Non-nil when Auto-Revert Tail Mode is active.
+Never set this variable directly, use the command
+`auto-revert-tail-mode' instead.")
+(put 'auto-revert-tail-mode 'permanent-local t)
-(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)
+(defvar auto-revert-timer nil
+ "Timer used by Auto-Revert Mode.")
(defcustom auto-revert-interval 5
- "Time, in seconds, between Auto-Revert Mode file checks."
+ "Time, in seconds, between Auto-Revert Mode file checks.
+The value may be an integer or floating point number.
+
+If a timer is already active, there are two ways to make sure
+that the new value will take effect immediately. You can set
+this variable through Custom or you can call the command
+`auto-revert-set-timer' after setting the variable. Otherwise,
+the new value will take effect the first time Auto Revert Mode
+calls `auto-revert-set-timer' for internal reasons or in your
+next editing session."
:group 'auto-revert
- :type 'integer)
+ :type 'number
+ :set (lambda (variable value)
+ (set-default variable value)
+ (and (boundp 'auto-revert-timer)
+ auto-revert-timer
+ (auto-revert-set-timer))))
(defcustom auto-revert-stop-on-user-input t
- "When non-nil Auto-Revert Mode stops checking files on user input."
+ "When non-nil, user input temporarily interrupts Auto-Revert Mode.
+With this setting, Auto-Revert Mode checks for user input after
+handling each buffer and does not process any further buffers
+\(until the next run of the timer) if user input is available.
+When nil, Auto-Revert Mode checks files and reverts buffers,
+with quitting disabled, without paying attention to user input.
+Thus, with this setting, Emacs might be non-responsive at times."
: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."
+ "When nil, Auto-Revert Mode does not generate any messages.
+When non-nil, a message is generated whenever a file is reverted."
:group 'auto-revert
:type 'boolean)
:group 'auto-revert
:type 'string)
+(defcustom auto-revert-tail-mode-text " Tail"
+ "String to display in the mode line when Auto-Revert Tail Mode is active.
+
+\(When the string is not empty, make sure that it has a leading space.)"
+ :group 'auto-revert
+ :type 'string
+ :version "22.1")
+
(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-...'
: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 nil, Global Auto-Revert mode operates only on file-visiting buffers.
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."
+`revert-buffer-function' and a `buffer-stale-function' are
+reverted by Global Auto-Revert mode. These include the Buffer
+List buffer, and Dired buffers showing complete local
+directories. Dired buffers do not auto-revert as a result of
+changes in subdirectories or in the contents, size, modes, etc.,
+of files. You may still sometimes want to revert them manually.
+
+Use this option with care since it could lead to excessive auto-reverts.
+For more information, see Info node `(emacs-xtra)Autorevert'."
:group 'auto-revert
- :type 'boolean)
+ :type 'boolean
+ :link '(info-link "(emacs-xtra)Autorevert"))
-(defcustom global-auto-revert-ignore-modes '()
+(defcustom global-auto-revert-ignore-modes ()
"List of major modes Global Auto-Revert Mode should not check."
:group 'auto-revert
:type '(repeat sexp))
:group 'auto-revert
:type 'hook)
+(defcustom auto-revert-check-vc-info nil
+ "If non-nil Auto Revert Mode reliably updates version control info.
+Auto Revert Mode updates version control info whenever the buffer
+needs reverting, regardless of the value of this variable.
+However, the version control state can change without changes to
+the work file. If the change is made from the current Emacs
+session, all info is updated. But if, for instance, a new
+version is checked in from outside the current Emacs session, the
+version control number in the mode line, as well as other version
+control related information, may not be properly updated. If you
+are worried about this, set this variable to a non-nil value.
+
+This currently works by automatically updating the version
+control info every `auto-revert-interval' seconds. Nevertheless,
+it should not cause excessive CPU usage on a reasonably fast
+machine, if it does not apply to too many version controlled
+buffers. CPU usage depends on the version control system."
+ :group 'auto-revert
+ :type 'boolean
+ :version "22.1")
+
(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 '()
+(defvar auto-revert-buffer-list ()
"List of buffers in Auto-Revert Mode.
Note that only Auto-Revert Mode, never Global Auto-Revert Mode, adds
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 '()
+(defvar auto-revert-remaining-buffers ()
"Buffers not checked when user input stopped execution.")
+(defvar auto-revert-tail-pos 0
+ "Position of last known end of file.")
+
+(add-hook 'find-file-hook
+ (lambda ()
+ (set (make-local-variable 'auto-revert-tail-pos)
+ (save-restriction (widen) (1- (point-max))))))
;; Functions:
;;;###autoload
-(defun auto-revert-mode (&optional arg)
+(define-minor-mode auto-revert-mode
"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")))
+Use `global-auto-revert-mode' to automatically revert all buffers.
+Use `auto-revert-tail-mode' if you know that the file will only grow
+without being changed in the part that is already in the buffer."
+ :group 'auto-revert :lighter auto-revert-mode-text
(if auto-revert-mode
(if (not (memq (current-buffer) auto-revert-buffer-list))
(push (current-buffer) auto-revert-buffer-list))
(auto-revert-set-timer)
(when auto-revert-mode
(auto-revert-buffers)
- (run-hooks 'auto-revert-mode-hook)))
+ (setq auto-revert-tail-mode nil)))
;;;###autoload
;;;###autoload
-(defun global-auto-revert-mode (&optional arg)
- "Revert any buffer when file on disk change.
+(define-minor-mode auto-revert-tail-mode
+ "Toggle reverting tail of buffer when file on disk grows.
+With arg, turn Tail mode on iff arg is positive.
+
+When Tail mode is enabled, the tail of the file is constantly
+followed, as with the shell command `tail -f'. This means that
+whenever the file grows on disk (presumably because some
+background process is appending to it from time to time), this is
+reflected in the current buffer.
+
+You can edit the buffer and turn this mode off and on again as
+you please. But make sure the background process has stopped
+writing before you save the file!
+
+Use `auto-revert-mode' for changes other than appends!"
+ :group 'find-file :lighter auto-revert-tail-mode-text
+ (when auto-revert-tail-mode
+ (unless buffer-file-name
+ (auto-revert-tail-mode 0)
+ (error "This buffer is not visiting a file"))
+ (if (and (buffer-modified-p)
+ (not auto-revert-tail-pos) ; library was loaded only after finding file
+ (not (y-or-n-p "Buffer is modified, so tail offset may be wrong. Proceed? ")))
+ (auto-revert-tail-mode 0)
+ ;; else we might reappend our own end when we save
+ (add-hook 'before-save-hook (lambda () (auto-revert-tail-mode 0)) nil t)
+ (or (local-variable-p 'auto-revert-tail-pos) ; don't lose prior position
+ (set (make-local-variable 'auto-revert-tail-pos)
+ (save-restriction (widen) (1- (point-max)))))
+ ;; let auto-revert-mode set up the mechanism for us if it isn't already
+ (or auto-revert-mode
+ (let ((auto-revert-tail-mode t))
+ (auto-revert-mode 1)))
+ (setq auto-revert-mode nil))))
+
+
+;;;###autoload
+(defun turn-on-auto-revert-tail-mode ()
+ "Turn on Auto-Revert Tail Mode.
+
+This function is designed to be added to hooks, for example:
+ (add-hook 'my-logfile-mode-hook 'turn-on-auto-revert-tail-mode)"
+ (auto-revert-tail-mode 1))
+
+
+;;;###autoload
+(define-minor-mode global-auto-revert-mode
+ "Revert any buffer when file on disk changes.
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")))
+ :global t :group 'auto-revert :lighter global-auto-revert-mode-text
(auto-revert-set-timer)
(when global-auto-revert-mode
- (auto-revert-buffers)
- (run-hooks 'global-auto-revert-mode-hook)))
+ (auto-revert-buffers)))
(defun auto-revert-set-timer ()
- "Restart or cancel the timer."
+ "Restart or cancel the timer used by Auto-Revert Mode.
+If such a timer is active, cancel it. Start a new timer if
+Global Auto-Revert Mode is active or if Auto-Revert Mode is active
+in some buffer. Restarting the timer ensures that Auto-Revert Mode
+will use an up-to-date value of `auto-revert-interval'"
+ (interactive)
(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)))
-
+ (setq auto-revert-timer
+ (if (or global-auto-revert-mode auto-revert-buffer-list)
+ (run-with-timer auto-revert-interval
+ auto-revert-interval
+ 'auto-revert-buffers))))
+
+(defun auto-revert-active-p ()
+ "Check if auto-revert is active (in current buffer or globally)."
+ (or auto-revert-mode
+ auto-revert-tail-mode
+ (and
+ global-auto-revert-mode
+ (not global-auto-revert-ignore-buffer)
+ (not (memq major-mode
+ global-auto-revert-ignore-modes)))))
+
+(defun auto-revert-handler ()
+ "Revert current buffer, if appropriate.
+This is an internal function used by Auto-Revert Mode."
+ (when (or auto-revert-tail-mode (not (buffer-modified-p)))
+ (let* ((buffer (current-buffer))
+ (revert
+ (or (and buffer-file-name
+ (not (file-remote-p buffer-file-name))
+ (file-readable-p buffer-file-name)
+ (not (verify-visited-file-modtime buffer)))
+ (and (or auto-revert-mode
+ global-auto-revert-non-file-buffers)
+ revert-buffer-function
+ (boundp 'buffer-stale-function)
+ (functionp buffer-stale-function)
+ (funcall buffer-stale-function t))))
+ eob eoblist)
+ (when revert
+ (when (and auto-revert-verbose
+ (not (eq revert 'fast)))
+ (message "Reverting buffer `%s'." (buffer-name)))
+ ;; If point (or a window point) is at the end of the buffer,
+ ;; we want to keep it at the end after reverting. This allows
+ ;; to tail a file.
+ (when buffer-file-name
+ (setq eob (eobp))
+ (walk-windows
+ #'(lambda (window)
+ (and (eq (window-buffer window) buffer)
+ (= (window-point window) (point-max))
+ (push window eoblist)))
+ 'no-mini t))
+ (if auto-revert-tail-mode
+ (auto-revert-tail-handler)
+ ;; Bind buffer-read-only in case user has done C-x C-q,
+ ;; so as not to forget that. This gives undesirable results
+ ;; when the file's mode changes, but that is less common.
+ (let ((buffer-read-only buffer-read-only))
+ (revert-buffer 'ignore-auto 'dont-ask 'preserve-modes)))
+ (when buffer-file-name
+ (when eob (goto-char (point-max)))
+ (dolist (window eoblist)
+ (set-window-point window (point-max)))))
+ ;; `preserve-modes' avoids changing the (minor) modes. But we
+ ;; do want to reset the mode for VC, so we do it manually.
+ (when (or revert auto-revert-check-vc-info)
+ (vc-find-file-hook)))))
+
+(defun auto-revert-tail-handler ()
+ (let ((size (nth 7 (file-attributes buffer-file-name)))
+ (modified (buffer-modified-p))
+ buffer-read-only ; ignore
+ (file buffer-file-name)
+ buffer-file-name) ; ignore that file has changed
+ (when (> size auto-revert-tail-pos)
+ (undo-boundary)
+ (save-restriction
+ (widen)
+ (save-excursion
+ (goto-char (point-max))
+ (insert-file-contents file nil auto-revert-tail-pos size)))
+ (undo-boundary)
+ (setq auto-revert-tail-pos size)
+ (set-buffer-modified-p modified)))
+ (set-visited-file-modtime))
(defun auto-revert-buffers ()
"Revert buffers as specified by Auto-Revert and Global Auto-Revert Mode.
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.
+Non-file buffers that have a custom `revert-buffer-function' and
+a `buffer-stale-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'.
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))))
+ (save-match-data
+ (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?
+ (with-current-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)
+ (not auto-revert-tail-mode)
+ (memq buf auto-revert-buffer-list))
+ (setq auto-revert-buffer-list
+ (delq buf auto-revert-buffer-list)))
+ (when (auto-revert-active-p) (auto-revert-handler)))
+ ;; 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.
+;;; arch-tag: f6bcb07b-4841-477e-9e44-b18678e58876
+;;; autorevert.el ends here