1;;; savehist.el --- Save minibuffer history. 2 3;; Copyright (C) 1997, 2005, 2006, 2007 Free Software Foundation, Inc. 4 5;; Author: Hrvoje Niksic <hniksic@xemacs.org> 6;; Keywords: minibuffer 7;; Version: 24 8 9;; This file is part of GNU Emacs. 10 11;; GNU Emacs is free software; you can redistribute it and/or modify 12;; it under the terms of the GNU General Public License as published by 13;; the Free Software Foundation; either version 2, or (at your option) 14;; any later version. 15 16;; GNU Emacs is distributed in the hope that it will be useful, 17;; but WITHOUT ANY WARRANTY; without even the implied warranty of 18;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19;; GNU General Public License for more details. 20 21;; You should have received a copy of the GNU General Public License 22;; along with GNU Emacs; see the file COPYING. If not, write to the 23;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 24;; Boston, MA 02110-1301, USA. 25 26;;; Commentary: 27 28;; Many editors (e.g. Vim) have the feature of saving minibuffer 29;; history to an external file after exit. This package provides the 30;; same feature in Emacs. When set up, it saves recorded minibuffer 31;; histories to a file (`~/.emacs-history' by default). Additional 32;; variables may be specified by customizing 33;; `savehist-additional-variables'. 34 35;; To use savehist, turn on savehist-mode by putting the following in 36;; `~/.emacs': 37;; 38;; (savehist-mode 1) 39;; 40;; or with customize: `M-x customize-option RET savehist-mode RET'. 41;; 42;; You can also explicitly save history with `M-x savehist-save' and 43;; load it by loading the `savehist-file' with `M-x load-file'. 44 45;; If you are using a version of Emacs that does not ship with this 46;; package, be sure to have `savehist.el' in a directory that is in 47;; your load-path, and to byte-compile it. 48 49;;; Code: 50 51(require 'custom) 52(eval-when-compile 53 (require 'cl)) 54 55;; User variables 56 57(defgroup savehist nil 58 "Save minibuffer history." 59 :version "22.1" 60 :group 'minibuffer) 61 62;;;###autoload 63(defcustom savehist-mode nil 64 "Mode for automatic saving of minibuffer history. 65Set this by calling the `savehist-mode' function or using the customize 66interface." 67 :type 'boolean 68 :set (lambda (symbol value) (savehist-mode (or value 0))) 69 :initialize 'custom-initialize-default 70 :require 'savehist 71 :group 'savehist) 72 73(defcustom savehist-save-minibuffer-history t 74 "*If non-nil, save all recorded minibuffer histories. 75If you want to save only specific histories, use `savehist-save-hook' to 76modify the value of `savehist-minibuffer-history-variables'." 77 :type 'boolean 78 :group 'savehist) 79 80(defcustom savehist-additional-variables () 81 "*List of additional variables to save. 82Each element is a symbol whose value will be persisted across Emacs 83sessions that use savehist. The contents of variables should be 84printable with the Lisp printer. You don't need to add minibuffer 85history variables to this list, all minibuffer histories will be 86saved automatically as long as `savehist-save-minibuffer-history' is 87non-nil. 88 89User options should be saved with the customize interface. This 90list is useful for saving automatically updated variables that are not 91minibuffer histories, such as `compile-command' or `kill-ring'." 92 :type '(repeat variable) 93 :group 'savehist) 94 95(defcustom savehist-ignored-variables nil ;; '(command-history) 96 "*List of additional variables not to save." 97 :type '(repeat variable) 98 :group 'savehist) 99 100(defcustom savehist-file 101 (cond 102 ;; Backward compatibility with previous versions of savehist. 103 ((file-exists-p "~/.emacs-history") "~/.emacs-history") 104 ((and (not (featurep 'xemacs)) (file-directory-p "~/.emacs.d/")) 105 "~/.emacs.d/history") 106 ((and (featurep 'xemacs) (file-directory-p "~/.xemacs/")) 107 "~/.xemacs/history") 108 ;; For users without `~/.emacs.d/' or `~/.xemacs/'. 109 (t "~/.emacs-history")) 110 "*File name where minibuffer history is saved to and loaded from. 111The minibuffer history is a series of Lisp expressions loaded 112automatically when `savehist-mode' is turned on. See `savehist-mode' 113for more details. 114 115If you want your minibuffer history shared between Emacs and XEmacs, 116customize this value and make sure that `savehist-coding-system' is 117set to a coding system that exists in both emacsen." 118 :type 'file 119 :group 'savehist) 120 121(defcustom savehist-file-modes #o600 122 "*Default permissions of the history file. 123This is decimal, not octal. The default is 384 (0600 in octal). 124Set to nil to use the default permissions that Emacs uses, typically 125mandated by umask. The default is a bit more restrictive to protect 126the user's privacy." 127 :type 'integer 128 :group 'savehist) 129 130(defcustom savehist-autosave-interval (* 5 60) 131 "*The interval between autosaves of minibuffer history. 132If set to nil, disables timer-based autosaving." 133 :type 'integer 134 :group 'savehist) 135 136(defcustom savehist-mode-hook nil 137 "Hook called when `savehist-mode' is turned on." 138 :type 'hook 139 :group 'savehist) 140 141(defcustom savehist-save-hook nil 142 "Hook called by `savehist-save' before saving the variables. 143You can use this hook to influence choice and content of variables to 144save." 145 :type 'hook 146 :group 'savehist) 147 148;; This should be capable of representing characters used by Emacs. 149;; We prefer UTF-8 over ISO 2022 because it is well-known outside 150;; Mule. XEmacs prir to 21.5 had UTF-8 provided by an external 151;; package which may not be loaded, which is why we check for version. 152(defvar savehist-coding-system (if (and (featurep 'xemacs) 153 (<= emacs-major-version 21) 154 (< emacs-minor-version 5)) 155 'iso-2022-8 'utf-8) 156 "The coding system savehist uses for saving the minibuffer history. 157Changing this value while Emacs is running is supported, but considered 158unwise, unless you know what you are doing.") 159 160;; Internal variables. 161 162(defvar savehist-timer nil) 163 164(defvar savehist-last-checksum nil) 165 166(defvar savehist-minibuffer-history-variables nil 167 "List of minibuffer histories. 168The contents of this variable is built while Emacs is running, and saved 169along with minibuffer history. You can change its value off 170`savehist-save-hook' to influence which variables are saved.") 171 172(defconst savehist-no-conversion (if (featurep 'xemacs) 'binary 'no-conversion) 173 "Coding system without any conversion. 174This is used for calculating an internal checksum. Should be as fast 175as possible, ideally simply exposing the internal representation of 176buffer text.") 177 178(defvar savehist-loaded nil 179 "Whether the history has already been loaded. 180This prevents toggling `savehist-mode' from destroying existing 181minibuffer history.") 182 183(when (featurep 'xemacs) 184 ;; Must declare this under XEmacs, which doesn't have built-in 185 ;; minibuffer history truncation. 186 (defvar history-length 100)) 187 188;; Functions. 189 190;;;###autoload 191(defun savehist-mode (arg) 192 "Toggle savehist-mode. 193Positive ARG turns on `savehist-mode'. When on, savehist-mode causes 194minibuffer history to be saved periodically and when exiting Emacs. 195When turned on for the first time in an Emacs session, it causes the 196previous minibuffer history to be loaded from `savehist-file'. 197 198This mode should normally be turned on from your Emacs init file. 199Calling it at any other time replaces your current minibuffer histories, 200which is probably undesirable." 201 (interactive "P") 202 (setq savehist-mode 203 (if (null arg) 204 (not savehist-mode) 205 (> (prefix-numeric-value arg) 0))) 206 (if (not savehist-mode) 207 (savehist-uninstall) 208 (when (and (not savehist-loaded) 209 (file-exists-p savehist-file)) 210 (condition-case errvar 211 (progn 212 ;; Don't set coding-system-for-read -- we rely on the 213 ;; coding cookie to convey that information. That way, if 214 ;; the user changes the value of savehist-coding-system, 215 ;; we can still correctly load the old file. 216 (load savehist-file nil (not (interactive-p))) 217 (setq savehist-loaded t)) 218 (error 219 ;; Don't install the mode if reading failed. Doing so would 220 ;; effectively destroy the user's data at the next save. 221 (setq savehist-mode nil) 222 (savehist-uninstall) 223 (signal (car errvar) (cdr errvar))))) 224 (savehist-install) 225 (run-hooks 'savehist-mode-hook)) 226 ;; Return the new setting. 227 savehist-mode) 228(add-minor-mode 'savehist-mode "") 229 230(defun savehist-load () 231 "Obsolete function provided for transition from old versions of savehist. 232Don't call this from new code, use (savehist-mode 1) instead. 233 234This function loads the variables stored in `savehist-file' and turns on 235`savehist-mode'. If `savehist-file' is in the old format that doesn't 236record the value of `savehist-minibuffer-history-variables', that value 237is deducted from the contents of the file." 238 (savehist-mode 1) 239 ;; Old versions of savehist distributed with XEmacs didn't save 240 ;; savehist-minibuffer-history-variables. If that variable is nil 241 ;; after loading the file, try to intuit the intended value. 242 (when (null savehist-minibuffer-history-variables) 243 (setq savehist-minibuffer-history-variables 244 (with-temp-buffer 245 (ignore-errors 246 (insert-file-contents savehist-file)) 247 (let ((vars ()) form) 248 (while (setq form (condition-case nil 249 (read (current-buffer)) (error nil))) 250 ;; Each form read is of the form (setq VAR VALUE). 251 ;; Collect VAR, i.e. (nth form 1). 252 (push (nth 1 form) vars)) 253 vars))))) 254(make-obsolete 'savehist-load 'savehist-mode) 255 256(defun savehist-install () 257 "Hook savehist into Emacs. 258Normally invoked by calling `savehist-mode' to set the minor mode. 259Installs `savehist-autosave' in `kill-emacs-hook' and on a timer. 260To undo this, call `savehist-uninstall'." 261 (add-hook 'minibuffer-setup-hook 'savehist-minibuffer-hook) 262 (add-hook 'kill-emacs-hook 'savehist-autosave) 263 ;; Install an invocation of savehist-autosave on a timer. This 264 ;; should not cause noticeable delays for users -- savehist-autosave 265 ;; executes in under 5 ms on my system. 266 (when (and savehist-autosave-interval 267 (null savehist-timer)) 268 (setq savehist-timer 269 (if (featurep 'xemacs) 270 (start-itimer 271 "savehist" 'savehist-autosave savehist-autosave-interval 272 savehist-autosave-interval) 273 (run-with-timer savehist-autosave-interval 274 savehist-autosave-interval 'savehist-autosave))))) 275 276(defun savehist-uninstall () 277 "Undo installing savehist. 278Normally invoked by calling `savehist-mode' to unset the minor mode." 279 (remove-hook 'minibuffer-setup-hook 'savehist-minibuffer-hook) 280 (remove-hook 'kill-emacs-hook 'savehist-autosave) 281 (when savehist-timer 282 (if (featurep 'xemacs) 283 (delete-itimer savehist-timer) 284 (cancel-timer savehist-timer)) 285 (setq savehist-timer nil))) 286 287(defun savehist-save (&optional auto-save) 288 "Save the values of minibuffer history variables. 289Unbound symbols referenced in `savehist-additional-variables' are ignored. 290If AUTO-SAVE is non-nil, compare the saved contents to the one last saved, 291 and don't save the buffer if they are the same." 292 (interactive) 293 (with-temp-buffer 294 (insert 295 (format ";; -*- mode: emacs-lisp; coding: %s -*-\n" savehist-coding-system) 296 ";; Minibuffer history file, automatically generated by `savehist'.\n\n") 297 (run-hooks 'savehist-save-hook) 298 (let ((print-length nil) 299 (print-string-length nil) 300 (print-level nil) 301 (print-readably t) 302 (print-quoted t)) 303 ;; Save the minibuffer histories, along with the value of 304 ;; savehist-minibuffer-history-variables itself. 305 (when savehist-save-minibuffer-history 306 (prin1 `(setq savehist-minibuffer-history-variables 307 ',savehist-minibuffer-history-variables) 308 (current-buffer)) 309 (insert ?\n) 310 (dolist (symbol savehist-minibuffer-history-variables) 311 (when (boundp symbol) 312 (let ((value (savehist-trim-history (symbol-value symbol)))) 313 (when value ; don't save empty histories 314 (prin1 `(setq ,symbol ',value) (current-buffer)) 315 (insert ?\n)))))) 316 ;; Save the additional variables. 317 (dolist (symbol savehist-additional-variables) 318 (when (boundp symbol) 319 (let ((value (symbol-value symbol))) 320 (when (savehist-printable value) 321 (prin1 `(setq ,symbol ',value) (current-buffer)) 322 (insert ?\n)))))) 323 ;; If autosaving, avoid writing if nothing has changed since the 324 ;; last write. 325 (let ((checksum (md5 (current-buffer) nil nil savehist-no-conversion))) 326 (unless (and auto-save (equal checksum savehist-last-checksum)) 327 ;; Set file-precious-flag when saving the buffer because we 328 ;; don't want a half-finished write ruining the entire 329 ;; history. Remember that this is run from a timer and from 330 ;; kill-emacs-hook, and also that multiple Emacs instances 331 ;; could write to this file at once. 332 (let ((file-precious-flag t) 333 (coding-system-for-write savehist-coding-system)) 334 (write-region (point-min) (point-max) savehist-file nil 335 (unless (interactive-p) 'quiet))) 336 (when savehist-file-modes 337 (set-file-modes savehist-file savehist-file-modes)) 338 (setq savehist-last-checksum checksum))))) 339 340(defun savehist-autosave () 341 "Save the minibuffer history if it has been modified since the last save. 342Does nothing if `savehist-mode' is off." 343 (when savehist-mode 344 (savehist-save t))) 345 346(defun savehist-trim-history (value) 347 "Retain only the first `history-length' items in VALUE. 348Only used under XEmacs, which doesn't (yet) implement automatic 349trimming of history lists to `history-length' items." 350 (if (and (featurep 'xemacs) 351 (natnump history-length) 352 (> (length value) history-length)) 353 ;; Equivalent to `(subseq value 0 history-length)', but doesn't 354 ;; need cl-extra at run-time. 355 (loop repeat history-length collect (pop value)) 356 value)) 357 358(defun savehist-printable (value) 359 "Return non-nil if VALUE is printable." 360 (cond 361 ;; Quick response for oft-encountered types known to be printable. 362 ((stringp value)) 363 ((numberp value)) 364 ((symbolp value)) 365 (t 366 ;; For others, check explicitly. 367 (with-temp-buffer 368 (condition-case nil 369 (let ((print-readably t) (print-level nil)) 370 ;; Print the value into a buffer... 371 (prin1 value (current-buffer)) 372 ;; ...and attempt to read it. 373 (read (point-min-marker)) 374 ;; The attempt worked: the object is printable. 375 t) 376 ;; The attempt failed: the object is not printable. 377 (error nil)))))) 378 379(defun savehist-minibuffer-hook () 380 (unless (or (eq minibuffer-history-variable t) 381 ;; XEmacs sets minibuffer-history-variable to t to mean "no 382 ;; history is being recorded". 383 (memq minibuffer-history-variable savehist-ignored-variables)) 384 (add-to-list 'savehist-minibuffer-history-variables 385 minibuffer-history-variable))) 386 387(provide 'savehist) 388 389;; arch-tag: b3ce47f4-c5ad-4ebc-ad02-73aba705cf9f 390 391;;; savehist.el ends here 392