emacs/lisp/buff-menu.el

;;; buff-menu.el --- buffer menu main function and support functions -*- coding:utf-8 -*-

;; Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 2000, 2001, 2002, 2003,
;;   2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.

;; Maintainer: FSF
;; Keywords: convenience

;; 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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; Edit, delete, or change attributes of all currently active Emacs
;; buffers from a list summarizing their state.  A good way to browse
;; any special or scratch buffers you have loaded, since you can't find
;; them by filename.  The single entry point is `list-buffers',
;; normally bound to C-x C-b.

;;; Change Log:

;; Buffer-menu-view: New function
;; Buffer-menu-view-other-window: New function

;; Merged by esr with recent mods to Emacs 19 buff-menu, 23 Mar 1993
;;
;; Modified by Bob Weiner, Motorola, Inc., 4/14/89
;;
;; Added optional backup argument to 'Buffer-menu-unmark' to make it undelete
;; current entry and then move to previous one.
;;
;; Based on FSF code dating back to 1985.

;;; Code:

;;Trying to preserve the old window configuration works well in
;;simple scenarios, when you enter the buffer menu, use it, and exit it.
;;But it does strange things when you switch back to the buffer list buffer
;;with C-x b, later on, when the window configuration is different.
;;The choice seems to be, either restore the window configuration
;;in all cases, or in no cases.
;;I decided it was better not to restore the window config at all. -- rms.

;;But since then, I changed buffer-menu to use the selected window,
;;so q now once again goes back to the previous window configuration.

;;(defvar Buffer-menu-window-config nil
;;  "Window configuration saved from entry to `buffer-menu'.")

;; Put buffer *Buffer List* into proper mode right away
;; so that from now on even list-buffers is enough to get a buffer menu.

(defgroup Buffer-menu nil
  "Show a menu of all buffers in a buffer."
  :group 'tools
  :group 'convenience)

(defcustom Buffer-menu-use-header-line t
  "Non-nil means to use an immovable header-line."
  :type 'boolean
  :group 'Buffer-menu)

(defface buffer-menu-buffer
  '((t (:weight bold)))
  "Face used to highlight buffer names in the buffer menu."
  :group 'Buffer-menu)
(put 'Buffer-menu-buffer 'face-alias 'buffer-menu-buffer)

(defcustom Buffer-menu-buffer+size-width 26
  "How wide to jointly make the buffer name and size columns."
  :type 'number
  :group 'Buffer-menu)

(defcustom Buffer-menu-mode-width 16
  "How wide to make the mode name column."
  :type 'number
  :group 'Buffer-menu)

(defcustom Buffer-menu-use-frame-buffer-list t
  "If non-nil, the Buffer Menu uses the selected frame's buffer list.
Buffers that were never selected in that frame are listed at the end.
If the value is nil, the Buffer Menu uses the global buffer list.
This variable matters if the Buffer Menu is sorted by visited order,
as it is by default."
  :type 'boolean
  :group 'Buffer-menu
  :version "22.1")

;; This should get updated & resorted when you click on a column heading
(defvar Buffer-menu-sort-column nil
  "Which column to sort the menu on.
Use 2 to sort by buffer names, or 5 to sort by file names.
A nil value means sort by visited order (the default).")

(defconst Buffer-menu-buffer-column 4)

(defvar Buffer-menu-files-only nil
  "Non-nil if the current buffer-menu lists only file buffers.
This variable determines whether reverting the buffer lists only
file buffers.  It affects both manual reverting and reverting by
Auto Revert Mode.")

(make-variable-buffer-local 'Buffer-menu-files-only)

(defvar Info-current-file) ;; from info.el
(defvar Info-current-node) ;; from info.el

(defvar Buffer-menu-mode-map
  (let ((map (make-keymap)))
    (suppress-keymap map t)
    (define-key map "q" 'quit-window)
    (define-key map "v" 'Buffer-menu-select)
    (define-key map "2" 'Buffer-menu-2-window)
    (define-key map "1" 'Buffer-menu-1-window)
    (define-key map "f" 'Buffer-menu-this-window)
    (define-key map "e" 'Buffer-menu-this-window)
    (define-key map "\C-m" 'Buffer-menu-this-window)
    (define-key map "o" 'Buffer-menu-other-window)
    (define-key map "\C-o" 'Buffer-menu-switch-other-window)
    (define-key map "s" 'Buffer-menu-save)
    (define-key map "d" 'Buffer-menu-delete)
    (define-key map "k" 'Buffer-menu-delete)
    (define-key map "\C-d" 'Buffer-menu-delete-backwards)
    (define-key map "\C-k" 'Buffer-menu-delete)
    (define-key map "x" 'Buffer-menu-execute)
    (define-key map " " 'next-line)
    (define-key map "n" 'next-line)
    (define-key map "p" 'previous-line)
    (define-key map "\177" 'Buffer-menu-backup-unmark)
    (define-key map "~" 'Buffer-menu-not-modified)
    (define-key map "?" 'describe-mode)
    (define-key map "u" 'Buffer-menu-unmark)
    (define-key map "m" 'Buffer-menu-mark)
    (define-key map "t" 'Buffer-menu-visit-tags-table)
    (define-key map "%" 'Buffer-menu-toggle-read-only)
    (define-key map "b" 'Buffer-menu-bury)
    (define-key map "g" 'Buffer-menu-revert)
    (define-key map "V" 'Buffer-menu-view)
    (define-key map "T" 'Buffer-menu-toggle-files-only)
    (define-key map [mouse-2] 'Buffer-menu-mouse-select)
    (define-key map [follow-link] 'mouse-face)
    (define-key map (kbd "M-s a C-s")   'Buffer-menu-isearch-buffers)
    (define-key map (kbd "M-s a M-C-s") 'Buffer-menu-isearch-buffers-regexp)
    map)
  "Local keymap for `Buffer-menu-mode' buffers.")

;; Buffer Menu mode is suitable only for specially formatted data.
(put 'Buffer-menu-mode 'mode-class 'special)

(define-derived-mode Buffer-menu-mode nil "Buffer Menu"
  "Major mode for editing a list of buffers.
Each line describes one of the buffers in Emacs.
Letters do not insert themselves; instead, they are commands.
\\<Buffer-menu-mode-map>
\\[Buffer-menu-mouse-select] -- select buffer you click on, in place of the buffer menu.
\\[Buffer-menu-this-window] -- select current line's buffer in place of the buffer menu.
\\[Buffer-menu-other-window] -- select that buffer in another window,
  so the buffer menu buffer remains visible in its window.
\\[Buffer-menu-view] -- select current line's buffer, but in view-mode.
\\[Buffer-menu-view-other-window] -- select that buffer in
  another window, in view-mode.
\\[Buffer-menu-switch-other-window] -- make another window display that buffer.
\\[Buffer-menu-mark] -- mark current line's buffer to be displayed.
\\[Buffer-menu-select] -- select current line's buffer.
  Also show buffers marked with m, in other windows.
\\[Buffer-menu-1-window] -- select that buffer in full-frame window.
\\[Buffer-menu-2-window] -- select that buffer in one window,
  together with buffer selected before this one in another window.
\\[Buffer-menu-isearch-buffers] -- Do incremental search in the marked buffers.
\\[Buffer-menu-isearch-buffers-regexp] -- Isearch for regexp in the marked buffers.
\\[Buffer-menu-visit-tags-table] -- visit-tags-table this buffer.
\\[Buffer-menu-not-modified] -- clear modified-flag on that buffer.
\\[Buffer-menu-save] -- mark that buffer to be saved, and move down.
\\[Buffer-menu-delete] -- mark that buffer to be deleted, and move down.
\\[Buffer-menu-delete-backwards] -- mark that buffer to be deleted, and move up.
\\[Buffer-menu-execute] -- delete or save marked buffers.
\\[Buffer-menu-unmark] -- remove all kinds of marks from current line.
  With prefix argument, also move up one line.
\\[Buffer-menu-backup-unmark] -- back up a line and remove marks.
\\[Buffer-menu-toggle-read-only] -- toggle read-only status of buffer on this line.
\\[Buffer-menu-revert] -- update the list of buffers.
\\[Buffer-menu-toggle-files-only] -- toggle whether the menu displays only file buffers.
\\[Buffer-menu-bury] -- bury the buffer listed on this line."
  (set (make-local-variable 'revert-buffer-function)
       'Buffer-menu-revert-function)
  (set (make-local-variable 'buffer-stale-function)
       #'(lambda (&optional noconfirm) 'fast))
  (setq truncate-lines t)
  (setq buffer-read-only t))

(define-obsolete-variable-alias 'buffer-menu-mode-hook
  'Buffer-menu-mode-hook "23.1")

;; This function exists so we can make the doc string of Buffer-menu-mode
;; look nice.
(defun Buffer-menu-revert ()
  "Update the list of buffers."
  (interactive)
  (revert-buffer))

(defun Buffer-menu-revert-function (ignore1 ignore2)
  (or (eq buffer-undo-list t)
      (setq buffer-undo-list nil))
  ;; We can not use save-excursion here.  The buffer gets erased.
  (let ((opoint (point))
	(eobp (eobp))
	(ocol (current-column))
	(oline (progn (move-to-column 4)
		      (get-text-property (point) 'buffer)))
	(prop (point-min))
	;; do not make undo records for the reversion.
	(buffer-undo-list t))
    ;; We can be called by Auto Revert Mode with the "*Buffer Menu*"
    ;; temporarily the current buffer.  Make sure that the
    ;; interactively current buffer is correctly identified with a `.'
    ;; by `list-buffers-noselect'.
    (with-current-buffer (window-buffer)
      (list-buffers-noselect Buffer-menu-files-only))
    (if oline
	(while (setq prop (next-single-property-change prop 'buffer))
	  (when (eq (get-text-property prop 'buffer) oline)
	    (goto-char prop)
	    (move-to-column ocol)))
      (goto-char (if eobp (point-max) opoint)))))

(defun Buffer-menu-toggle-files-only (arg)
  "Toggle whether the current buffer-menu displays only file buffers.
With a positive ARG display only file buffers.  With zero or
negative ARG, display other buffers as well."
  (interactive "P")
  (setq Buffer-menu-files-only
	(cond ((not arg) (not Buffer-menu-files-only))
	      ((> (prefix-numeric-value arg) 0) t)))
  (revert-buffer))


(defun Buffer-menu-buffer (error-if-non-existent-p)
  "Return buffer described by this line of buffer menu."
  (let* ((where (save-excursion
		  (beginning-of-line)
		  (+ (point) Buffer-menu-buffer-column)))
	 (name (and (not (eobp)) (get-text-property where 'buffer-name)))
	 (buf (and (not (eobp)) (get-text-property where 'buffer))))
    (if name
	(or (get-buffer name)
	    (and buf (buffer-name buf) buf)
	    (if error-if-non-existent-p
		(error "No buffer named `%s'" name)
	      nil))
      (or (and buf (buffer-name buf) buf)
	  (if error-if-non-existent-p
	      (error "No buffer on this line")
	    nil)))))

(defun buffer-menu (&optional arg)
  "Make a menu of buffers so you can save, delete or select them.
With argument, show only buffers that are visiting files.
Type ? after invocation to get help on commands available.
Type q to remove the buffer menu from the display.

The first column shows `>' for a buffer you have
marked to be displayed, `D' for one you have marked for
deletion, and `.' for the current buffer.

The C column has a `.' for the buffer from which you came.
The R column has a `%' if the buffer is read-only.
The M column has a `*' if it is modified,
or `S' if you have marked it for saving.
After this come the buffer name, its size in characters,
its major mode, and the visited file name (if any)."
  (interactive "P")
;;;  (setq Buffer-menu-window-config (current-window-configuration))
  (switch-to-buffer (list-buffers-noselect arg))
  (message
   "Commands: d, s, x, u; f, o, 1, 2, m, v; ~, %%; q to quit; ? for help."))

(defun buffer-menu-other-window (&optional arg)
  "Display a list of buffers in another window.
With the buffer list buffer, you can save, delete or select the buffers.
With argument, show only buffers that are visiting files.
Type ? after invocation to get help on commands available.
Type q to remove the buffer menu from the display.
For more information, see the function `buffer-menu'."
  (interactive "P")
;;;  (setq Buffer-menu-window-config (current-window-configuration))
  (switch-to-buffer-other-window (list-buffers-noselect arg))
  (message
   "Commands: d, s, x, u; f, o, 1, 2, m, v; ~, %%; q to quit; ? for help."))

(defun Buffer-menu-no-header ()
  (beginning-of-line)
  (if (or Buffer-menu-use-header-line
	  (not (eq (char-after) ?C)))
      t
    (ding)
    (forward-line 1)
    nil))

(defun Buffer-menu-mark ()
  "Mark buffer on this line for being displayed by \\<Buffer-menu-mode-map>\\[Buffer-menu-select] command."
  (interactive)
  (when (Buffer-menu-no-header)
    (let ((inhibit-read-only t))
      (delete-char 1)
      (insert ?>)
      (forward-line 1))))

(defun Buffer-menu-unmark (&optional backup)
  "Cancel all requested operations on buffer on this line and move down.
Optional prefix arg means move up."
  (interactive "P")
  (when (Buffer-menu-no-header)
    (let* ((buf (Buffer-menu-buffer t))
	   (mod (buffer-modified-p buf))
	   (readonly (with-current-buffer buf buffer-read-only))
	   (inhibit-read-only t))
      (delete-char 3)
      (insert (if readonly (if mod " %*" " % ") (if mod "  *" "   ")))))
  (forward-line (if backup -1 1)))

(defun Buffer-menu-backup-unmark ()
  "Move up and cancel all requested operations on buffer on line above."
  (interactive)
  (forward-line -1)
  (Buffer-menu-unmark)
  (forward-line -1))

(defun Buffer-menu-delete (&optional arg)
  "Mark buffer on this line to be deleted by \\<Buffer-menu-mode-map>\\[Buffer-menu-execute] command.
Prefix arg is how many buffers to delete.
Negative arg means delete backwards."
  (interactive "p")
  (when (Buffer-menu-no-header)
    (let ((inhibit-read-only t))
      (if (or (null arg) (= arg 0))
	  (setq arg 1))
      (while (> arg 0)
	(delete-char 1)
	(insert ?D)
	(forward-line 1)
	(setq arg (1- arg)))
      (while (and (< arg 0)
		  (Buffer-menu-no-header))
	(delete-char 1)
	(insert ?D)
	(forward-line -1)
	(setq arg (1+ arg))))))

(defun Buffer-menu-delete-backwards (&optional arg)
  "Mark buffer on this line to be deleted by \\<Buffer-menu-mode-map>\\[Buffer-menu-execute] command
and then move up one line.  Prefix arg means move that many lines."
  (interactive "p")
  (Buffer-menu-delete (- (or arg 1))))

(defun Buffer-menu-save ()
  "Mark buffer on this line to be saved by \\<Buffer-menu-mode-map>\\[Buffer-menu-execute] command."
  (interactive)
  (when (Buffer-menu-no-header)
    (let ((inhibit-read-only t))
      (forward-char 2)
      (delete-char 1)
      (insert ?S)
      (forward-line 1))))

(defun Buffer-menu-not-modified (&optional arg)
  "Mark buffer on this line as unmodified (no changes to save)."
  (interactive "P")
  (with-current-buffer (Buffer-menu-buffer t)
    (set-buffer-modified-p arg))
  (save-excursion
   (beginning-of-line)
   (forward-char 2)
   (if (= (char-after) (if arg ?\s ?*))
       (let ((inhibit-read-only t))
	 (delete-char 1)
	 (insert (if arg ?* ?\s))))))

(defun Buffer-menu-beginning ()
  (goto-char (point-min))
  (unless Buffer-menu-use-header-line
    (forward-line)))

(defun Buffer-menu-execute ()
  "Save and/or delete buffers marked with \\<Buffer-menu-mode-map>\\[Buffer-menu-save] or \\<Buffer-menu-mode-map>\\[Buffer-menu-delete] commands."
  (interactive)
  (save-excursion
    (Buffer-menu-beginning)
    (while (re-search-forward "^..S" nil t)
      (let ((modp nil))
	(with-current-buffer (Buffer-menu-buffer t)
	  (save-buffer)
	  (setq modp (buffer-modified-p)))
	(let ((inhibit-read-only t))
	  (delete-char -1)
	  (insert (if modp ?* ?\s))))))
  (save-excursion
    (Buffer-menu-beginning)
    (let ((buff-menu-buffer (current-buffer))
	  (inhibit-read-only t))
      (while (re-search-forward "^D" nil t)
	(forward-char -1)
	(let ((buf (Buffer-menu-buffer nil)))
	  (or (eq buf nil)
	      (eq buf buff-menu-buffer)
	      (save-excursion (kill-buffer buf)))
	  (if (and buf (buffer-name buf))
	    (progn (delete-char 1)
		   (insert ?\s))
	  (delete-region (point) (progn (forward-line 1) (point)))
	    (unless (bobp)
	      (forward-char -1))))))))

(defun Buffer-menu-select ()
  "Select this line's buffer; also display buffers marked with `>'.
You can mark buffers with the \\<Buffer-menu-mode-map>\\[Buffer-menu-mark] command.
This command deletes and replaces all the previously existing windows
in the selected frame."
  (interactive)
  (let ((buff (Buffer-menu-buffer t))
	(menu (current-buffer))
	(others ())
	tem)
    (Buffer-menu-beginning)
    (while (re-search-forward "^>" nil t)
      (setq tem (Buffer-menu-buffer t))
      (let ((inhibit-read-only t))
	(delete-char -1)
	(insert ?\s))
      (or (eq tem buff) (memq tem others) (setq others (cons tem others))))
    (setq others (nreverse others)
	  tem (/ (1- (frame-height)) (1+ (length others))))
    (delete-other-windows)
    (switch-to-buffer buff)
    (or (eq menu buff)
	(bury-buffer menu))
    (if (equal (length others) 0)
	(progn
;;;	  ;; Restore previous window configuration before displaying
;;;	  ;; selected buffers.
;;;	  (if Buffer-menu-window-config
;;;	      (progn
;;;		(set-window-configuration Buffer-menu-window-config)
;;;		(setq Buffer-menu-window-config nil)))
	  (switch-to-buffer buff))
      (while others
	(split-window nil tem)
	(other-window 1)
	(switch-to-buffer (car others))
	(setq others (cdr others)))
      (other-window 1)  			;back to the beginning!
)))

(defun Buffer-menu-marked-buffers ()
  "Return a list of buffers marked with the \\<Buffer-menu-mode-map>\\[Buffer-menu-mark] command."
  (let (buffers)
    (Buffer-menu-beginning)
    (while (re-search-forward "^>" nil t)
      (setq buffers (cons (Buffer-menu-buffer t) buffers)))
    (nreverse buffers)))

(defun Buffer-menu-isearch-buffers ()
  "Search for a string through all marked buffers using Isearch."
  (interactive)
  (multi-isearch-buffers (Buffer-menu-marked-buffers)))

(defun Buffer-menu-isearch-buffers-regexp ()
  "Search for a regexp through all marked buffers using Isearch."
  (interactive)
  (multi-isearch-buffers-regexp (Buffer-menu-marked-buffers)))


(defun Buffer-menu-visit-tags-table ()
  "Visit the tags table in the buffer on this line.  See `visit-tags-table'."
  (interactive)
  (let ((file (buffer-file-name (Buffer-menu-buffer t))))
    (if file
	(visit-tags-table file)
      (error "Specified buffer has no file"))))

(defun Buffer-menu-1-window ()
  "Select this line's buffer, alone, in full frame."
  (interactive)
  (switch-to-buffer (Buffer-menu-buffer t))
  (bury-buffer (other-buffer))
  (delete-other-windows))

(defun Buffer-menu-mouse-select (event)
  "Select the buffer whose line you click on."
  (interactive "e")
  (let (buffer)
    (with-current-buffer (window-buffer (posn-window (event-end event)))
      (save-excursion
	(goto-char (posn-point (event-end event)))
	(setq buffer (Buffer-menu-buffer t))))
    (select-window (posn-window (event-end event)))
    (if (and (window-dedicated-p (selected-window))
	     (eq (selected-window) (frame-root-window)))
	(switch-to-buffer-other-frame buffer)
      (switch-to-buffer buffer))))

(defun Buffer-menu-this-window ()
  "Select this line's buffer in this window."
  (interactive)
  (switch-to-buffer (Buffer-menu-buffer t)))

(defun Buffer-menu-other-window ()
  "Select this line's buffer in other window, leaving buffer menu visible."
  (interactive)
  (switch-to-buffer-other-window (Buffer-menu-buffer t)))

(defun Buffer-menu-switch-other-window ()
  "Make the other window select this line's buffer.
The current window remains selected."
  (interactive)
  (let ((pop-up-windows t)
	same-window-buffer-names
	same-window-regexps)
    (display-buffer (Buffer-menu-buffer t))))

(defun Buffer-menu-2-window ()
  "Select this line's buffer, with previous buffer in second window."
  (interactive)
  (let ((buff (Buffer-menu-buffer t))
	(menu (current-buffer))
	(pop-up-windows t)
	same-window-buffer-names
	same-window-regexps)
    (delete-other-windows)
    (switch-to-buffer (other-buffer))
    (pop-to-buffer buff)
    (bury-buffer menu)))

(defun Buffer-menu-toggle-read-only ()
  "Toggle read-only status of buffer on this line, perhaps via version control."
  (interactive)
  (let (char)
    (with-current-buffer (Buffer-menu-buffer t)
      (toggle-read-only)
      (setq char (if buffer-read-only ?% ?\s)))
    (save-excursion
      (beginning-of-line)
      (forward-char 1)
      (if (/= (following-char) char)
          (let ((inhibit-read-only t))
            (delete-char 1)
            (insert char))))))

(defun Buffer-menu-bury ()
  "Bury the buffer listed on this line."
  (interactive)
  (when (Buffer-menu-no-header)
    (save-excursion
      (beginning-of-line)
      (bury-buffer (Buffer-menu-buffer t))
      (let ((line (buffer-substring (point) (progn (forward-line 1) (point))))
            (inhibit-read-only t))
        (delete-region (point) (progn (forward-line -1) (point)))
        (goto-char (point-max))
        (insert line))
      (message "Buried buffer moved to the end"))))


(defun Buffer-menu-view ()
  "View this line's buffer in View mode."
  (interactive)
  (view-buffer (Buffer-menu-buffer t)))


(defun Buffer-menu-view-other-window ()
  "View this line's buffer in View mode in another window."
  (interactive)
  (view-buffer-other-window (Buffer-menu-buffer t)))


(define-key ctl-x-map "\C-b" 'list-buffers)

(defun list-buffers (&optional files-only)
  "Display a list of names of existing buffers.
The list is displayed in a buffer named `*Buffer List*'.
Note that buffers with names starting with spaces are omitted.
Non-null optional arg FILES-ONLY means mention only file buffers.

For more information, see the function `buffer-menu'."
  (interactive "P")
  (display-buffer (list-buffers-noselect files-only)))

(defconst Buffer-menu-short-ellipsis
  ;; This file is preloaded, so we can't use char-displayable-p here
  ;; because we don't know yet what display we're going to connect to.
  ":" ;; (if (char-displayable-p ?…) "…" ":")
  )

(defun Buffer-menu-buffer+size (name size &optional name-props size-props)
  (if (> (+ (string-width name) (string-width size) 2)
         Buffer-menu-buffer+size-width)
      (setq name
            (let ((tail
                   (if (string-match "<[0-9]+>$" name)
                       (match-string 0 name)
                     "")))
              (concat (truncate-string-to-width
                       name
                       (- Buffer-menu-buffer+size-width
                          (max (string-width size) 3)
                          (string-width tail)
                          2))
                      Buffer-menu-short-ellipsis
                      tail)))
    ;; Don't put properties on (buffer-name).
    (setq name (copy-sequence name)))
  (add-text-properties 0 (length name) name-props name)
  (add-text-properties 0 (length size) size-props size)
  (concat name
	  (make-string (- Buffer-menu-buffer+size-width
			  (string-width name)
			  (string-width size))
		       ?\s)
	  size))

(defun Buffer-menu-sort (column)
  "Sort the buffer menu by COLUMN."
  (interactive "P")
  (when column
    (setq column (prefix-numeric-value column))
    (if (< column 2) (setq column 2))
    (if (> column 5) (setq column 5)))
  (setq Buffer-menu-sort-column column)
  (let ((inhibit-read-only t) l buf m1 m2)
    (save-excursion
      (Buffer-menu-beginning)
      (while (not (eobp))
	(when (buffer-live-p (setq buf (get-text-property (+ (point) 4) 'buffer)))
	  (setq m1 (char-after)
		m1 (if (memq m1 '(?> ?D)) m1)
		m2 (char-after (+ (point) 2))
		m2 (if (eq m2 ?S) m2))
	  (if (or m1 m2)
	      (push (list buf m1 m2) l)))
	(forward-line)))
    (Buffer-menu-revert)
    (save-excursion
      (Buffer-menu-beginning)
      (while (not (eobp))
	(when (setq buf (assq (get-text-property (+ (point) 4) 'buffer) l))
	  (setq m1 (cadr buf)
		m2 (cadr (cdr buf)))
	  (when m1
	    (delete-char 1)
	    (insert m1)
	    (backward-char 1))
	  (when m2
	    (forward-char 2)
	    (delete-char 1)
	    (insert m2)))
	(forward-line)))))

(defun Buffer-menu-sort-by-column (&optional e)
  "Sort the buffer menu by the column clicked on."
  (interactive (list last-input-event))
  (if e (mouse-select-window e))
  (let* ((pos (event-start e))
	 (obj (posn-object pos))
	 (col (if obj
		  (get-text-property (cdr obj) 'column (car obj))
		(get-text-property (posn-point pos) 'column))))
    (Buffer-menu-sort col)))

(defvar Buffer-menu-sort-button-map
  (let ((map (make-sparse-keymap)))
    ;; This keymap handles both nil and non-nil values for
    ;; Buffer-menu-use-header-line.
    (define-key map [header-line mouse-1] 'Buffer-menu-sort-by-column)
    (define-key map [header-line mouse-2] 'Buffer-menu-sort-by-column)
    (define-key map [mouse-2] 'Buffer-menu-sort-by-column)
    (define-key map [follow-link] 'mouse-face)
    (define-key map "\C-m" 'Buffer-menu-sort-by-column)
    map)
  "Local keymap for Buffer menu sort buttons.")

(defun Buffer-menu-make-sort-button (name column)
  (if (equal column Buffer-menu-sort-column) (setq column nil))
  (propertize name
	      'column column
	      'help-echo (concat
			  (if Buffer-menu-use-header-line
			      "mouse-1, mouse-2: sort by "
			    "mouse-2, RET: sort by ")
			  (if column (downcase name) "visited order"))
	      'mouse-face 'highlight
	      'keymap Buffer-menu-sort-button-map))

(defun list-buffers-noselect (&optional files-only buffer-list)
  "Create and return a buffer with a list of names of existing buffers.
The buffer is named `*Buffer List*'.
Note that buffers with names starting with spaces are omitted.
Non-null optional arg FILES-ONLY means mention only file buffers.

If BUFFER-LIST is non-nil, it should be a list of buffers;
it means list those buffers and no others.

For more information, see the function `buffer-menu'."
  (let* ((old-buffer (current-buffer))
	 (standard-output standard-output)
	 (mode-end (make-string (- Buffer-menu-mode-width 2) ?\s))
	 (header (concat "CRM "
			 (Buffer-menu-buffer+size
			  (Buffer-menu-make-sort-button "Buffer" 2)
			  (Buffer-menu-make-sort-button "Size" 3))
			 "  "
			 (Buffer-menu-make-sort-button "Mode" 4) mode-end
			 (Buffer-menu-make-sort-button "File" 5) "\n"))
	 list desired-point)
    (when Buffer-menu-use-header-line
      (let ((pos 0))
	;; Turn whitespace chars in the header into stretch specs so
	;; they work regardless of the header-line face.
	(while (string-match "[ \t\n]+" header pos)
	  (setq pos (match-end 0))
	  (put-text-property (match-beginning 0) pos 'display
			     ;; Assume fixed-size chars in the buffer.
			     (list 'space :align-to pos)
			     header)))
      ;; Try to better align the one-char headers.
      (put-text-property 0 3 'face 'fixed-pitch header)
      ;; Add a "dummy" leading space to align the beginning of the header
      ;; line with the beginning of the text (rather than with the left
      ;; scrollbar or the left fringe).  --Stef
      (setq header (concat (propertize " " 'display '(space :align-to 0))
			   header)))
    (with-current-buffer (get-buffer-create "*Buffer List*")
      (setq buffer-read-only nil)
      (erase-buffer)
      (setq standard-output (current-buffer))
      (unless Buffer-menu-use-header-line
        ;; Use U+2014 (EM DASH) to underline if possible, else use ASCII
        ;; (i.e. U+002D, HYPHEN-MINUS).
	(let ((underline (if (char-displayable-p ?\u2014) ?\u2014 ?-)))
	  (insert header
		  (apply 'string
			 (mapcar (lambda (c)
				   (if (memq c '(?\n ?\s)) c underline))
				 header)))))
      ;; Collect info for every buffer we're interested in.
      (dolist (buffer (or buffer-list
			  (buffer-list
			   (when Buffer-menu-use-frame-buffer-list
			     (selected-frame)))))
	(with-current-buffer buffer
	  (let ((name (buffer-name))
		(file buffer-file-name))
	    (unless (and (not buffer-list)
			 (or
			  ;; Don't mention internal buffers.
			  (and (string= (substring name 0 1) " ") (null file))
			  ;; Maybe don't mention buffers without files.
			  (and files-only (not file))
			  (string= name "*Buffer List*")))
	      ;; Otherwise output info.
	      (let ((mode (concat (format-mode-line mode-name nil nil buffer)
				  (if mode-line-process
				      (format-mode-line mode-line-process
							nil nil buffer))))
		    (bits (string
			   (if (eq buffer old-buffer) ?. ?\s)
			   ;; Handle readonly status.  The output buffer
			   ;; is special cased to appear readonly; it is
			   ;; actually made so at a later date.
			   (if (or (eq buffer standard-output)
				   buffer-read-only)
			       ?% ?\s)
			   ;; Identify modified buffers.
			   (if (buffer-modified-p) ?* ?\s)
			   ;; Space separator.
			   ?\s)))
		(unless file
		  ;; No visited file.  Check local value of
		  ;; list-buffers-directory and, for Info buffers,
		  ;; Info-current-file.
		  (cond ((and (boundp 'list-buffers-directory)
			      list-buffers-directory)
			 (setq file list-buffers-directory))
			((eq major-mode 'Info-mode)
			 (setq file Info-current-file)
			 (cond
			  ((equal file "dir")
			   (setq file "*Info Directory*"))
			  ((eq file 'apropos)
			   (setq file "*Info Apropos*"))
			  ((eq file 'history)
			   (setq file "*Info History*"))
			  ((eq file 'toc)
			   (setq file "*Info TOC*"))
			  ((not (stringp file))  ;; avoid errors
			   (setq file nil))
			  (t
			   (setq file (concat "("
					      (file-name-nondirectory file)
					      ") "
					      Info-current-node)))))))
		(push (list buffer bits name (buffer-size) mode file)
		      list))))))
      ;; Preserve the original buffer-list ordering, just in case.
      (setq list (nreverse list))
      ;; Place the buffers's info in the output buffer, sorted if necessary.
      (dolist (buffer
	       (if Buffer-menu-sort-column
		   (sort list
			 (if (eq Buffer-menu-sort-column 3)
			     (lambda (a b)
			       (< (nth Buffer-menu-sort-column a)
				  (nth Buffer-menu-sort-column b)))
			   (lambda (a b)
			     (string< (nth Buffer-menu-sort-column a)
				      (nth Buffer-menu-sort-column b)))))
		 list))
	(if (eq (car buffer) old-buffer)
	    (setq desired-point (point)))
	(insert (cadr buffer)
		;; Put the buffer name into a text property
		;; so we don't have to extract it from the text.
		;; This way we avoid problems with unusual buffer names.
		(let ((name (nth 2 buffer))
		      (size (int-to-string (nth 3 buffer))))
		      (Buffer-menu-buffer+size name size
		         `(buffer-name ,name
				       buffer ,(car buffer)
				       font-lock-face buffer-menu-buffer
				       mouse-face highlight
				       help-echo
				       ,(if (>= (length name)
						(- Buffer-menu-buffer+size-width
						   (max (length size) 3)
						   2))
					    name
					  "mouse-2: select this buffer"))))
		"  "
		(if (> (string-width (nth 4 buffer)) Buffer-menu-mode-width)
		    (truncate-string-to-width (nth 4 buffer)
					      Buffer-menu-mode-width)
		  (nth 4 buffer)))
	(when (nth 5 buffer)
	  (indent-to (+ Buffer-menu-buffer-column Buffer-menu-buffer+size-width
			Buffer-menu-mode-width 4) 1)
	  (princ (abbreviate-file-name (nth 5 buffer))))
	(princ "\n"))
      (Buffer-menu-mode)
      (when Buffer-menu-use-header-line
	(setq header-line-format header))
      ;; DESIRED-POINT doesn't have to be set; it is not when the
      ;; current buffer is not displayed for some reason.
      (and desired-point
	   (goto-char desired-point))
      (setq Buffer-menu-files-only files-only)
      (set-buffer-modified-p nil)
      (current-buffer))))

;; arch-tag: e7dfcfc9-6cb2-46e4-bf55-8ef1936d83c6
;;; buff-menu.el ends here