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55535639 | 1 | ;;; saveplace.el --- automatically save place in files |
722074ef | 2 | |
0d30b337 | 3 | ;; Copyright (C) 1993, 1994, 2001, 2002, 2003, 2004, |
aaef169d | 4 | ;; 2005, 2006 Free Software Foundation, Inc. |
722074ef | 5 | |
19a448e3 | 6 | ;; Author: Karl Fogel <kfogel@red-bean.com> |
722074ef RS |
7 | ;; Maintainer: FSF |
8 | ;; Created: July, 1993 | |
722074ef RS |
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 | |
b578f267 | 24 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
086add15 LK |
25 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
26 | ;; Boston, MA 02110-1301, USA. | |
b578f267 | 27 | |
6f96f4c9 RS |
28 | ;;; Commentary: |
29 | ||
722074ef RS |
30 | ;; Automatically save place in files, so that visiting them later |
31 | ;; (even during a different Emacs session) automatically moves point | |
32 | ;; to the saved position, when the file is first found. Uses the | |
33 | ;; value of buffer-local variable save-place to determine whether to | |
34 | ;; save position or not. | |
35 | ;; | |
e7dc77f6 RS |
36 | ;; Thanks to Stefan Schoef, who sent a patch with the |
37 | ;; `save-place-version-control' stuff in it. | |
722074ef | 38 | |
6f96f4c9 RS |
39 | ;;; Code: |
40 | ||
722074ef RS |
41 | ;; this is what I was using during testing: |
42 | ;; (define-key ctl-x-map "p" 'toggle-save-place) | |
43 | ||
20606f3d RS |
44 | (defgroup save-place nil |
45 | "Automatically save place in files." | |
46 | :group 'data) | |
47 | ||
48 | ||
722074ef RS |
49 | (defvar save-place-alist nil |
50 | "Alist of saved places to go back to when revisiting files. | |
51 | Each element looks like (FILENAME . POSITION); | |
52 | visiting file FILENAME goes automatically to position POSITION | |
53 | rather than the beginning of the buffer. | |
54 | This alist is saved between Emacs sessions.") | |
55 | ||
20606f3d | 56 | (defcustom save-place nil |
722074ef RS |
57 | "*Non-nil means automatically save place in each file. |
58 | This means when you visit a file, point goes to the last place | |
59 | where it was when you previously visited the same file. | |
60 | This variable is automatically buffer-local. | |
61 | ||
62 | If you wish your place in any file to always be automatically saved, | |
63 | simply put this in your `~/.emacs' file: | |
64 | ||
c73dca25 RS |
65 | \(setq-default save-place t) |
66 | \(require 'saveplace) | |
67 | ||
68 | or else use the Custom facility to set this option." | |
20606f3d | 69 | :type 'boolean |
d749f559 | 70 | :require 'saveplace |
20606f3d | 71 | :group 'save-place) |
722074ef RS |
72 | |
73 | (make-variable-buffer-local 'save-place) | |
74 | ||
20606f3d RS |
75 | (defcustom save-place-file (convert-standard-filename "~/.emacs-places") |
76 | "*Name of the file that records `save-place-alist' value." | |
77 | :type 'file | |
78 | :group 'save-place) | |
722074ef | 79 | |
a4ce5ede | 80 | (defcustom save-place-version-control nil |
e7dc77f6 RS |
81 | "*Controls whether to make numbered backups of master save-place file. |
82 | It can have four values: t, nil, `never', and `nospecial'. The first | |
83 | three have the same meaning that they do for the variable | |
84 | `version-control', and the final value `nospecial' means just use the | |
20606f3d RS |
85 | value of `version-control'." |
86 | :type '(radio (const :tag "Unconditionally" t) | |
87 | (const :tag "For VC Files" nil) | |
88 | (const never) | |
a4ce5ede | 89 | (const :tag "Use value of `version-control'" nospecial)) |
20606f3d | 90 | :group 'save-place) |
e7dc77f6 | 91 | |
722074ef RS |
92 | (defvar save-place-loaded nil |
93 | "Non-nil means that the `save-place-file' has been loaded.") | |
94 | ||
20606f3d RS |
95 | (defcustom save-place-limit nil |
96 | "Maximum number of entries to retain in the list; nil means no limit." | |
97 | :type '(choice (integer :tag "Entries" :value 1) | |
98 | (const :tag "No Limit" nil)) | |
99 | :group 'save-place) | |
6cf02570 | 100 | |
467997b7 EZ |
101 | (defcustom save-place-forget-unreadable-files t |
102 | "Non-nil means forget place in unreadable files. | |
103 | ||
104 | The filenames in `save-place-alist' that do not match | |
105 | `save-place-skip-check-regexp' are filtered through | |
106 | `file-readable-p'. if nil, their alist entries are removed. | |
107 | ||
108 | You may do this anytime by calling the complementary function, | |
109 | `save-place-forget-unreadable-files'. When this option is turned on, | |
110 | this happens automatically before saving `save-place-alist' to | |
111 | `save-place-file'." | |
112 | :type 'boolean :group 'save-place) | |
113 | ||
114 | (defcustom save-place-save-skipped t | |
115 | "If non-nil, remember files matching `save-place-skip-check-regexp'. | |
116 | ||
117 | When filtering `save-place-alist' for unreadable files, some will not | |
118 | be checked, based on said regexp, and instead saved or forgotten based | |
119 | on this flag." | |
120 | :type 'boolean :group 'save-place) | |
121 | ||
122 | (defcustom save-place-skip-check-regexp | |
123 | ;; thanks to ange-ftp-name-format | |
124 | "\\`/\\(?:cdrom\\|floppy\\|mnt\\|\\(?:[^@/:]*@\\)?[^@/:]*[^@/:.]:\\)" | |
125 | "Regexp whose file names shall not be checked for readability. | |
126 | ||
127 | When forgetting unreadable files, file names matching this regular | |
128 | expression shall not be checked for readability, but instead be | |
129 | subject to `save-place-save-skipped'. | |
130 | ||
131 | Files for which such a check may be inconvenient include those on | |
132 | removable and network volumes." | |
133 | :type 'regexp :group 'save-place) | |
134 | ||
722074ef RS |
135 | (defun toggle-save-place (&optional parg) |
136 | "Toggle whether to save your place in this file between sessions. | |
137 | If this mode is enabled, point is recorded when you kill the buffer | |
138 | or exit Emacs. Visiting this file again will go to that position, | |
139 | even in a later Emacs session. | |
140 | ||
141 | If called with a prefix arg, the mode is enabled if and only if | |
142 | the argument is positive. | |
143 | ||
144 | To save places automatically in all files, put this in your `.emacs' file: | |
145 | ||
146 | \(setq-default save-place t\)" | |
147 | (interactive "P") | |
148 | (if (not buffer-file-name) | |
44a75d48 | 149 | (message "Buffer `%s' not visiting a file" (buffer-name)) |
722074ef RS |
150 | (if (and save-place (or (not parg) (<= parg 0))) |
151 | (progn | |
44a75d48 | 152 | (message "No place will be saved in this file") |
722074ef | 153 | (setq save-place nil)) |
44a75d48 | 154 | (message "Place will be saved") |
722074ef RS |
155 | (setq save-place t)))) |
156 | ||
157 | (defun save-place-to-alist () | |
158 | ;; put filename and point in a cons box and then cons that onto the | |
159 | ;; front of the save-place-alist, if save-place is non-nil. | |
160 | ;; Otherwise, just delete that file from the alist. | |
161 | ;; first check to make sure alist has been loaded in from the master | |
162 | ;; file. If not, do so, then feel free to modify the alist. It | |
163 | ;; will be saved again when Emacs is killed. | |
164 | (or save-place-loaded (load-save-place-alist-from-file)) | |
165 | (if buffer-file-name | |
166 | (progn | |
a59f6ba3 KH |
167 | (let ((cell (assoc buffer-file-name save-place-alist)) |
168 | (position (if (not (eq major-mode 'hexl-mode)) | |
169 | (point) | |
06e24ef7 RS |
170 | (with-no-warnings |
171 | (1+ (hexl-current-address)))))) | |
722074ef | 172 | (if cell |
a59f6ba3 KH |
173 | (setq save-place-alist (delq cell save-place-alist))) |
174 | (if (and save-place | |
175 | (not (= position 1))) ;; Optimize out the degenerate case. | |
176 | (setq save-place-alist | |
177 | (cons (cons buffer-file-name position) | |
178 | save-place-alist))))))) | |
722074ef | 179 | |
467997b7 EZ |
180 | (defun save-place-forget-unreadable-files () |
181 | "Remove unreadable files from `save-place-alist'. | |
182 | For each entry in the alist, if `file-readable-p' returns nil for the | |
183 | filename, remove the entry. Save the new alist \(as the first pair | |
184 | may have changed\) back to `save-place-alist'." | |
185 | (interactive) | |
186 | ;; the following was adapted from an in-place filtering function, | |
187 | ;; `filter-mod', used in the original. | |
188 | (unless (null save-place-alist) ;says it better than `when' | |
189 | ;; first, check all except first | |
190 | (let ((fmprev save-place-alist) (fmcur (cdr save-place-alist))) | |
191 | (while fmcur ;not null | |
192 | ;; a value is only saved when it becomes FMPREV. | |
193 | (if (if (string-match save-place-skip-check-regexp (caar fmcur)) | |
194 | save-place-save-skipped | |
195 | (file-readable-p (caar fmcur))) | |
196 | (setq fmprev fmcur) | |
197 | (setcdr fmprev (cdr fmcur))) | |
198 | (setq fmcur (cdr fmcur)))) | |
199 | ;; test first pair, keep it if OK, otherwise 2nd element, which | |
200 | ;; may be '() | |
201 | (unless (if (string-match save-place-skip-check-regexp | |
202 | (caar save-place-alist)) | |
203 | save-place-save-skipped | |
204 | (file-readable-p (caar save-place-alist))) | |
205 | (setq save-place-alist (cdr save-place-alist))))) | |
206 | ||
722074ef RS |
207 | (defun save-place-alist-to-file () |
208 | (let ((file (expand-file-name save-place-file))) | |
209 | (save-excursion | |
b483a3c1 | 210 | (message "Saving places to %s..." file) |
722074ef RS |
211 | (set-buffer (get-buffer-create " *Saved Places*")) |
212 | (delete-region (point-min) (point-max)) | |
467997b7 EZ |
213 | (when save-place-forget-unreadable-files |
214 | (save-place-forget-unreadable-files)) | |
5f29a6c8 KF |
215 | (let ((print-length nil) |
216 | (print-level nil)) | |
217 | (print save-place-alist (current-buffer))) | |
e7dc77f6 RS |
218 | (let ((version-control |
219 | (cond | |
220 | ((null save-place-version-control) nil) | |
221 | ((eq 'never save-place-version-control) 'never) | |
222 | ((eq 'nospecial save-place-version-control) version-control) | |
223 | (t | |
224 | t)))) | |
6b98170f | 225 | (condition-case nil |
cfde584f RS |
226 | ;; Don't use write-file; we don't want this buffer to visit it. |
227 | (write-region (point-min) (point-max) file) | |
6b98170f | 228 | (file-error (message "Can't write %s" file))) |
e7dc77f6 | 229 | (kill-buffer (current-buffer)) |
b483a3c1 | 230 | (message "Saving places to %s...done" file))))) |
722074ef RS |
231 | |
232 | (defun load-save-place-alist-from-file () | |
233 | (if (not save-place-loaded) | |
234 | (progn | |
235 | (setq save-place-loaded t) | |
236 | (let ((file (expand-file-name save-place-file))) | |
237 | ;; make sure that the alist does not get overwritten, and then | |
238 | ;; load it if it exists: | |
239 | (if (file-readable-p file) | |
240 | (save-excursion | |
c7abb182 | 241 | (message "Loading places from %s..." file) |
722074ef RS |
242 | ;; don't want to use find-file because we have been |
243 | ;; adding hooks to it. | |
244 | (set-buffer (get-buffer-create " *Saved Places*")) | |
245 | (delete-region (point-min) (point-max)) | |
246 | (insert-file-contents file) | |
247 | (goto-char (point-min)) | |
f1180544 | 248 | (setq save-place-alist |
722074ef RS |
249 | (car (read-from-string |
250 | (buffer-substring (point-min) (point-max))))) | |
6cf02570 RS |
251 | |
252 | ;; If there is a limit, and we're over it, then we'll | |
253 | ;; have to truncate the end of the list: | |
254 | (if save-place-limit | |
255 | (if (<= save-place-limit 0) | |
256 | ;; Zero gets special cased. I'm not thrilled | |
257 | ;; with this, but the loop for >= 1 is tight. | |
258 | (setq save-place-alist nil) | |
259 | ;; Else the limit is >= 1, so enforce it by | |
260 | ;; counting and then `setcdr'ing. | |
261 | (let ((s save-place-alist) | |
262 | (count 1)) | |
263 | (while s | |
264 | (if (>= count save-place-limit) | |
265 | (setcdr s nil) | |
266 | (setq count (1+ count))) | |
267 | (setq s (cdr s)))))) | |
f1180544 | 268 | |
722074ef | 269 | (kill-buffer (current-buffer)) |
91eac6da | 270 | (message "Loading places from %s...done" file))) |
722074ef RS |
271 | nil)))) |
272 | ||
273 | (defun save-places-to-alist () | |
274 | ;; go through buffer-list, saving places to alist if save-place is | |
275 | ;; non-nil, deleting them from alist if it is nil. | |
276 | (let ((buf-list (buffer-list))) | |
277 | (while buf-list | |
278 | ;; put this into a save-excursion in case someone is counting on | |
279 | ;; another function in kill-emacs-hook to act on the last buffer | |
280 | ;; they were in: | |
281 | (save-excursion | |
282 | (set-buffer (car buf-list)) | |
283 | ;; save-place checks buffer-file-name too, but we can avoid | |
284 | ;; overhead of function call by checking here too. | |
285 | (and buffer-file-name (save-place-to-alist)) | |
286 | (setq buf-list (cdr buf-list)))))) | |
b6ace927 RS |
287 | |
288 | (defun save-place-find-file-hook () | |
289 | (or save-place-loaded (load-save-place-alist-from-file)) | |
290 | (let ((cell (assoc buffer-file-name save-place-alist))) | |
291 | (if cell | |
6f96f4c9 RS |
292 | (progn |
293 | (or after-find-file-from-revert-buffer | |
294 | (goto-char (cdr cell))) | |
b6ace927 RS |
295 | ;; and make sure it will be saved again for later |
296 | (setq save-place t))))) | |
297 | ||
4d2c9a10 | 298 | (defun save-place-kill-emacs-hook () |
18b1fecd RS |
299 | ;; First update the alist. This loads the old save-place-file if nec. |
300 | (save-places-to-alist) | |
301 | ;; Now save the alist in the file, if we have ever loaded the file | |
302 | ;; (including just now). | |
52b9a931 | 303 | (if save-place-loaded |
18b1fecd | 304 | (save-place-alist-to-file))) |
b6ace927 | 305 | |
1a4914f3 | 306 | (add-hook 'find-file-hook 'save-place-find-file-hook t) |
b6ace927 RS |
307 | |
308 | (add-hook 'kill-emacs-hook 'save-place-kill-emacs-hook) | |
722074ef RS |
309 | |
310 | (add-hook 'kill-buffer-hook 'save-place-to-alist) | |
311 | ||
312 | (provide 'saveplace) ; why not... | |
313 | ||
ab5796a9 | 314 | ;;; arch-tag: 3c2ef47b-0a22-4558-b116-118c9ef454a0 |
722074ef | 315 | ;;; saveplace.el ends here |