1;;; saveplace.el --- automatically save place in files. 2 3;; Copyright (C) 1993, 1994 Free Software Foundation, Inc. 4 5;; Author: Karl Fogel <kfogel@cs.oberlin.edu> 6;; Maintainer: FSF 7;; Created: July, 1993 8;; Version: 1.2 9;; Keywords: bookmarks, placeholders 10 11;; This file is part of GNU Emacs. 12 13;; GNU Emacs is free software; you can redistribute it and/or modify 14;; it under the terms of the GNU General Public License as published by 15;; the Free Software Foundation; either version 2, or (at your option) 16;; any later version. 17 18;; GNU Emacs is distributed in the hope that it will be useful, 19;; but WITHOUT ANY WARRANTY; without even the implied warranty of 20;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21;; GNU General Public License for more details. 22 23;; You should have received a copy of the GNU General Public License 24;; along with GNU Emacs; see the file COPYING. If not, write to 25;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 26 27;; Automatically save place in files, so that visiting them later 28;; (even during a different Emacs session) automatically moves point 29;; to the saved position, when the file is first found. Uses the 30;; value of buffer-local variable save-place to determine whether to 31;; save position or not. 32;; 33;; Thanks to Stefan Schoef, who sent a patch with the 34;; `save-place-version-control' stuff in it. 35 36;; this is what I was using during testing: 37;; (define-key ctl-x-map "p" 'toggle-save-place) 38 39(defvar save-place-alist nil 40 "Alist of saved places to go back to when revisiting files. 41Each element looks like (FILENAME . POSITION); 42visiting file FILENAME goes automatically to position POSITION 43rather than the beginning of the buffer. 44This alist is saved between Emacs sessions.") 45 46(defvar save-place nil 47 "*Non-nil means automatically save place in each file. 48This means when you visit a file, point goes to the last place 49where it was when you previously visited the same file. 50This variable is automatically buffer-local. 51 52If you wish your place in any file to always be automatically saved, 53simply put this in your `~/.emacs' file: 54 55\(setq-default save-place t\)") 56 57(make-variable-buffer-local 'save-place) 58 59(defvar save-place-file "~/.emacs-places" 60 "*Name of the file that records `save-place-alist' value.") 61 62(defvar save-place-version-control 'nospecial 63 "*Controls whether to make numbered backups of master save-place file. 64It can have four values: t, nil, `never', and `nospecial'. The first 65three have the same meaning that they do for the variable 66`version-control', and the final value `nospecial' means just use the 67value of `version-control'.") 68 69(defvar save-place-loaded nil 70 "Non-nil means that the `save-place-file' has been loaded.") 71 72(defun toggle-save-place (&optional parg) 73 "Toggle whether to save your place in this file between sessions. 74If this mode is enabled, point is recorded when you kill the buffer 75or exit Emacs. Visiting this file again will go to that position, 76even in a later Emacs session. 77 78If called with a prefix arg, the mode is enabled if and only if 79the argument is positive. 80 81To save places automatically in all files, put this in your `.emacs' file: 82 83\(setq-default save-place t\)" 84 (interactive "P") 85 (if (not buffer-file-name) 86 (message 87 (format "Buffer \"%s\" not visiting a file." (buffer-name))) 88 (if (and save-place (or (not parg) (<= parg 0))) 89 (progn 90 (message "No place will be saved in this file.") 91 (setq save-place nil)) 92 (message "Place will be saved.") 93 (setq save-place t)))) 94 95(defun save-place-to-alist () 96 ;; put filename and point in a cons box and then cons that onto the 97 ;; front of the save-place-alist, if save-place is non-nil. 98 ;; Otherwise, just delete that file from the alist. 99 ;; first check to make sure alist has been loaded in from the master 100 ;; file. If not, do so, then feel free to modify the alist. It 101 ;; will be saved again when Emacs is killed. 102 (or save-place-loaded (load-save-place-alist-from-file)) 103 (if buffer-file-name 104 (progn 105 (let ((cell (assoc buffer-file-name save-place-alist))) 106 (if cell 107 (setq save-place-alist (delq cell save-place-alist)))) 108 (if save-place 109 (setq save-place-alist 110 (cons (cons buffer-file-name (point)) 111 save-place-alist)))))) 112 113(defun save-place-alist-to-file () 114 (let ((file (expand-file-name save-place-file))) 115 (save-excursion 116 (message (format "Saving places to %s..." file)) 117 (set-buffer (get-buffer-create " *Saved Places*")) 118 (delete-region (point-min) (point-max)) 119 (if (file-readable-p file) 120 (insert-file-contents file)) 121 (delete-region (point-min) (point-max)) 122 (goto-char (point-min)) 123 (print save-place-alist (current-buffer)) 124 (let ((version-control 125 (cond 126 ((null save-place-version-control) nil) 127 ((eq 'never save-place-version-control) 'never) 128 ((eq 'nospecial save-place-version-control) version-control) 129 (t 130 t)))) 131 (write-file file) 132 (kill-buffer (current-buffer)) 133 (message (format "Saving places to %s... done." file)))))) 134 135(defun load-save-place-alist-from-file () 136 (if (not save-place-loaded) 137 (progn 138 (setq save-place-loaded t) 139 (let ((file (expand-file-name save-place-file))) 140 ;; make sure that the alist does not get overwritten, and then 141 ;; load it if it exists: 142 (if (file-readable-p file) 143 (save-excursion 144 (message (format "Loading places from %s..." 145 save-place-file)) 146 ;; don't want to use find-file because we have been 147 ;; adding hooks to it. 148 (set-buffer (get-buffer-create " *Saved Places*")) 149 (delete-region (point-min) (point-max)) 150 (insert-file-contents file) 151 (goto-char (point-min)) 152 (setq save-place-alist 153 (car (read-from-string 154 (buffer-substring (point-min) (point-max))))) 155 (kill-buffer (current-buffer)) 156 (message (format "Loading places from %s... done." file)) 157 t) 158 t) 159 nil)))) 160 161(defun save-places-to-alist () 162 ;; go through buffer-list, saving places to alist if save-place is 163 ;; non-nil, deleting them from alist if it is nil. 164 (let ((buf-list (buffer-list))) 165 (while buf-list 166 ;; put this into a save-excursion in case someone is counting on 167 ;; another function in kill-emacs-hook to act on the last buffer 168 ;; they were in: 169 (save-excursion 170 (set-buffer (car buf-list)) 171 ;; save-place checks buffer-file-name too, but we can avoid 172 ;; overhead of function call by checking here too. 173 (and buffer-file-name (save-place-to-alist)) 174 (setq buf-list (cdr buf-list)))))) 175 176(defun save-place-find-file-hook () 177 (or save-place-loaded (load-save-place-alist-from-file)) 178 (let ((cell (assoc buffer-file-name save-place-alist))) 179 (if cell 180 (progn 181 (goto-char (cdr cell)) 182 ;; and make sure it will be saved again for later 183 (setq save-place t))))) 184 185(defun save-place-kill-emacs-hook () 186 (save-places-to-alist) 187 (save-place-alist-to-file)) 188 189(add-hook 'find-file-hooks 'save-place-find-file-hook t) 190 191(add-hook 'kill-emacs-hook 'save-place-kill-emacs-hook) 192 193(add-hook 'kill-buffer-hook 'save-place-to-alist) 194 195(provide 'saveplace) ; why not... 196 197;;; saveplace.el ends here 198 199