;;; savehist.el --- Save minibuffer history.
-;; Copyright (C) 1997, 2005 Free Software Foundation
+;; Copyright (C) 1997, 2005, 2006 Free Software Foundation
;; Author: Hrvoje Niksic <hniksic@xemacs.org>
;; Keywords: minibuffer
-;; Version: 7
+;; Version: 24
;; This file is part of GNU Emacs.
;; Many editors (e.g. Vim) have the feature of saving minibuffer
;; history to an external file after exit. This package provides the
-;; same feature in Emacs. When Emacs is about the exit,
-;; `savehist-save' will dump the contents of various minibuffer
-;; histories (as determined by `savehist-history-variables') to a save
-;; file (`~/.emacs-history' by default). Although the package was
-;; designed for saving the minibuffer histories, any variables can be
-;; saved that way.
-
-;; To use savehist, put the following to `~/.emacs':
+;; same feature in Emacs. When set up, it saves recorded minibuffer
+;; histories to a file (`~/.emacs-history' by default). Additional
+;; variables may be specified by customizing
+;; `savehist-additional-variables'.
+
+;; To use savehist, turn on savehist-mode by putting the following in
+;; `~/.emacs':
+;;
+;; (savehist-mode 1)
+;;
+;; or with customize: `M-x customize-option RET savehist-mode RET'.
;;
-;; (require 'savehist)
-;; (savehist-load)
+;; You can also explicitly save history with `M-x savehist-save' and
+;; load it by loading the `savehist-file' with `M-x load-file'.
-;; Be sure to have `savehist.el' in a directory that is in your
-;; load-path, and byte-compile it.
+;; If you are using a version of Emacs that does not ship with this
+;; package, be sure to have `savehist.el' in a directory that is in
+;; your load-path, and to byte-compile it.
;;; Code:
(require 'custom)
-(require 'cl)
+(eval-when-compile
+ (require 'cl))
;; User variables
(defgroup savehist nil
"Save minibuffer history."
+ :version "22.1"
:group 'minibuffer)
-(defcustom savehist-history-variables
- '(
- ;; Catch-all minibuffer history
- minibuffer-history
- ;; File-oriented commands
- file-name-history
- ;; Regexp-related reads
- regexp-history
- ;; Searches in minibuffer (via `M-r' and such)
- minibuffer-history-search-history
- ;; Query replace
- query-replace-history
- ;; eval-expression (`M-:')
- read-expression-history
- ;; shell-command (`M-!')
- shell-command-history
- ;; compile
- compile-history
- ;; find-tag (`M-.')
- find-tag-history
- ;; grep
- grep-history
- ;; Viper stuff
- vip-ex-history vip-search-history
- vip-replace1-history vip-replace2-history
- vip-shell-history vip-search-history
-
- ;; XEmacs-specific:
- ;; Buffer-related commands
- buffer-history
- ;; Reads of variables and functions
- variable-history function-history
- ;; Extended commands
- read-command-history
-
- ;; Info, lookup, and bookmark historys
- Info-minibuffer-history
- Info-search-history
- Manual-page-minibuffer-history
-
- ;; Emacs-specific:
- ;; Extended commands
- extended-command-history)
- "*List of symbols to be saved.
-Every symbol should refer to a variable. The variable will be saved
-only if it is bound and has a non-nil value. Thus it is safe to
-specify a superset of the variables a user is expected to want to
-save.
-
-Default value contains minibuffer history variables used by Emacs, XEmacs,
-and Viper (uh-oh). Note that, if you customize this variable, you
-can lose the benefit of future versions of Emacs adding new values to
-the list. Because of that it might be more useful to add values using
-`add-to-list'."
- :type '(repeat (symbol :tag "Variable"))
+;;;###autoload
+(defcustom savehist-mode nil
+ "Mode for automatic saving of minibuffer history.
+Set this by calling the `savehist-mode' function or using the customize
+interface."
+ :type 'boolean
+ :set (lambda (symbol value) (savehist-mode (or value 0)))
+ :initialize 'custom-initialize-default
+ :require 'savehist
:group 'savehist)
-(defcustom savehist-file "~/.emacs-history"
- "*File name to save minibuffer history to.
-The minibuffer history is a series of Lisp expressions, which should be
-loaded using `savehist-load' from your .emacs. See `savehist-load' for
-more details."
- :type 'file
+(defcustom savehist-save-minibuffer-history t
+ "*If non-nil, save all recorded minibuffer histories.
+If you want to save only specific histories, use `savehist-save-hook' to
+modify the value of `savehist-minibuffer-history-variables'."
+ :type 'boolean
+ :group 'savehist)
+
+(defcustom savehist-additional-variables ()
+ "*List of additional variables to save.
+Each element is a symbol whose value will be persisted across Emacs
+sessions that use savehist. The contents of variables should be
+printable with the Lisp printer. You don't need to add minibuffer
+history variables to this list, all minibuffer histories will be
+saved automatically as long as `savehist-save-minibuffer-history' is
+non-nil.
+
+User options should be saved with the customize interface. This
+list is useful for saving automatically updated variables that are not
+minibuffer histories, such as `compile-command' or `kill-ring'."
+ :type '(repeat variable)
+ :group 'savehist)
+
+(defcustom savehist-ignored-variables nil ;; '(command-history)
+ "*List of additional variables not to save."
+ :type '(repeat variable)
:group 'savehist)
-(defcustom savehist-length 100
- "*Maximum length of a minibuffer list.
-If set to nil, the length is unlimited."
- :type '(choice integer
- (const :tag "Unlimited" nil))
+(defcustom savehist-file
+ (cond
+ ;; Backward compatibility with previous versions of savehist.
+ ((file-exists-p "~/.emacs-history") "~/.emacs-history")
+ ((and (not (featurep 'xemacs)) (file-directory-p "~/.emacs.d/"))
+ "~/.emacs.d/history")
+ ((and (featurep 'xemacs) (file-directory-p "~/.xemacs/"))
+ "~/.xemacs/history")
+ ;; For users without `~/.emacs.d/' or `~/.xemacs/'.
+ (t "~/.emacs-history"))
+ "*File name where minibuffer history is saved to and loaded from.
+The minibuffer history is a series of Lisp expressions loaded
+automatically when `savehist-mode' is turned on. See `savehist-mode'
+for more details.
+
+If you want your minibuffer history shared between Emacs and XEmacs,
+customize this value and make sure that `savehist-coding-system' is
+set to a coding system that exists in both emacsen."
+ :type 'file
:group 'savehist)
-(defcustom savehist-modes #o600
+(defcustom savehist-file-modes #o600
"*Default permissions of the history file.
This is decimal, not octal. The default is 384 (0600 in octal).
Set to nil to use the default permissions that Emacs uses, typically
:group 'savehist)
(defcustom savehist-autosave-interval (* 5 60)
- "*The interval during which savehist should autosave the history buffer."
+ "*The interval between autosaves of minibuffer history.
+If set to nil, disables timer-based autosaving."
:type 'integer
:group 'savehist)
-(defconst savehist-xemacs (string-match "XEmacs" emacs-version))
+(defcustom savehist-mode-hook nil
+ "Hook called when `savehist-mode' is turned on."
+ :type 'hook
+ :group 'savehist)
+
+(defcustom savehist-save-hook nil
+ "Hook called by `savehist-save' before saving the variables.
+You can use this hook to influence choice and content of variables to
+save."
+ :type 'hook
+ :group 'savehist)
-(defvar savehist-coding-system (if savehist-xemacs 'iso-2022-8 'utf-8)
+;; This should be capable of representing characters used by Emacs.
+;; We prefer UTF-8 over ISO 2022 because it is well-known outside
+;; Mule. XEmacs prir to 21.5 had UTF-8 provided by an external
+;; package which may not be loaded, which is why we check for version.
+(defvar savehist-coding-system (if (and (featurep 'xemacs)
+ (<= emacs-major-version 21)
+ (< emacs-minor-version 5))
+ 'iso-2022-8 'utf-8)
"The coding system savehist uses for saving the minibuffer history.
Changing this value while Emacs is running is supported, but considered
unwise, unless you know what you are doing.")
(defvar savehist-last-checksum nil)
-;; Coding system without conversion, only used for calculating and
-;; comparing checksums.
-(defconst savehist-no-conversion (if savehist-xemacs 'binary 'no-conversion))
+(defvar savehist-minibuffer-history-variables nil
+ "List of minibuffer histories.
+The contents of this variable is built while Emacs is running, and saved
+along with minibuffer history. You can change its value off
+`savehist-save-hook' to influence which variables are saved.")
+
+(defconst savehist-no-conversion (if (featurep 'xemacs) 'binary 'no-conversion)
+ "Coding system without any conversion.
+This is used for calculating an internal checksum. Should be as fast
+as possible, ideally simply exposing the internal representation of
+buffer text.")
+
+(defvar savehist-loaded nil
+ "Whether the history has already been loaded.
+This prevents toggling `savehist-mode' from destroying existing
+minibuffer history.")
+
+(when (featurep 'xemacs)
+ ;; Must declare this under XEmacs, which doesn't have built-in
+ ;; minibuffer history truncation.
+ (defvar history-length 100))
\f
-;; Functions
+;; Functions.
;;;###autoload
-(defun savehist-load (&optional no-hook)
- "Load the minibuffer histories from `savehist-file'.
-Unless NO-HOOK is specified, the function will also add the save function
-to `kill-emacs-hook' and on a timer, ensuring that the minibuffer contents
-will be saved before leaving Emacs.
-
-This function should be normally used from your Emacs init file. Since it
-removes your current minibuffer histories, it is unwise to call it at any
-other time."
+(defun savehist-mode (arg)
+ "Toggle savehist-mode.
+Positive ARG turns on `savehist-mode'. When on, savehist-mode causes
+minibuffer history to be saved periodically and when exiting Emacs.
+When turned on for the first time in an Emacs session, it causes the
+previous minibuffer history to be loaded from `savehist-file'.
+
+This mode should normally be turned on from your Emacs init file.
+Calling it at any other time replaces your current minibuffer histories,
+which is probably undesirable."
(interactive "P")
- (unless no-hook
- (add-hook 'kill-emacs-hook 'savehist-autosave)
- ;; Install an invocation of savehist-autosave on a timer. This
- ;; should not cause a noticeable delay -- savehist-autosave
- ;; executes in under 5 ms on my system.
- (unless savehist-timer
- (setq savehist-timer
- (if savehist-xemacs
- (start-itimer
- "savehist" 'savehist-autosave savehist-autosave-interval
- savehist-autosave-interval)
- (run-with-timer savehist-autosave-interval savehist-autosave-interval
- 'savehist-autosave)))))
- ;; Don't set coding-system-for-read here. We rely on autodetection
- ;; and the coding cookie to convey that information. That way, if
- ;; the user changes the value of savehist-coding-system, we can
- ;; still correctly load the old file.
- (load savehist-file t (not (interactive-p))))
+ (setq savehist-mode
+ (if (null arg)
+ (not savehist-mode)
+ (> (prefix-numeric-value arg) 0)))
+ (if (not savehist-mode)
+ (savehist-uninstall)
+ (when (and (not savehist-loaded)
+ (file-exists-p savehist-file))
+ (condition-case errvar
+ (progn
+ ;; Don't set coding-system-for-read -- we rely on the
+ ;; coding cookie to convey that information. That way, if
+ ;; the user changes the value of savehist-coding-system,
+ ;; we can still correctly load the old file.
+ (load savehist-file nil (not (interactive-p)))
+ (setq savehist-loaded t))
+ (error
+ ;; Don't install the mode if reading failed. Doing so would
+ ;; effectively destroy the user's data at the next save.
+ (setq savehist-mode nil)
+ (savehist-uninstall)
+ (signal (car errvar) (cdr errvar)))))
+ (savehist-install)
+ (run-hooks 'savehist-mode-hook))
+ ;; Return the new setting.
+ savehist-mode)
+(add-minor-mode 'savehist-mode "")
+
+(defun savehist-load ()
+ "Obsolete function provided for transition from old versions of savehist.
+Don't call this from new code, use (savehist-mode 1) instead.
+
+This function loads the variables stored in `savehist-file' and turns on
+`savehist-mode'. If `savehist-file' is in the old format that doesn't
+record the value of `savehist-minibuffer-history-variables', that value
+is deducted from the contents of the file."
+ (savehist-mode 1)
+ ;; Old versions of savehist distributed with XEmacs didn't save
+ ;; savehist-minibuffer-history-variables. If that variable is nil
+ ;; after loading the file, try to intuit the intended value.
+ (when (null savehist-minibuffer-history-variables)
+ (setq savehist-minibuffer-history-variables
+ (with-temp-buffer
+ (ignore-errors
+ (insert-file-contents savehist-file))
+ (let ((vars ()) form)
+ (while (setq form (condition-case nil
+ (read (current-buffer)) (error nil)))
+ ;; Each form read is of the form (setq VAR VALUE).
+ ;; Collect VAR, i.e. (nth form 1).
+ (push (nth 1 form) vars))
+ vars)))))
+(make-obsolete 'savehist-load 'savehist-mode)
+
+(defun savehist-install ()
+ "Hook savehist into Emacs.
+Normally invoked by calling `savehist-mode' to set the minor mode.
+Installs `savehist-autosave' in `kill-emacs-hook' and on a timer.
+To undo this, call `savehist-uninstall'."
+ (add-hook 'minibuffer-setup-hook 'savehist-minibuffer-hook)
+ (add-hook 'kill-emacs-hook 'savehist-autosave)
+ ;; Install an invocation of savehist-autosave on a timer. This
+ ;; should not cause noticeable delays for users -- savehist-autosave
+ ;; executes in under 5 ms on my system.
+ (when (and savehist-autosave-interval
+ (null savehist-timer))
+ (setq savehist-timer
+ (if (featurep 'xemacs)
+ (start-itimer
+ "savehist" 'savehist-autosave savehist-autosave-interval
+ savehist-autosave-interval)
+ (run-with-timer savehist-autosave-interval
+ savehist-autosave-interval 'savehist-autosave)))))
+
+(defun savehist-uninstall ()
+ "Undo installing savehist.
+Normally invoked by calling `savehist-mode' to unset the minor mode."
+ (remove-hook 'minibuffer-setup-hook 'savehist-minibuffer-hook)
+ (remove-hook 'kill-emacs-hook 'savehist-autosave)
+ (when savehist-timer
+ (if (featurep 'xemacs)
+ (delete-itimer savehist-timer)
+ (cancel-timer savehist-timer))
+ (setq savehist-timer nil)))
-;;;###autoload
(defun savehist-save (&optional auto-save)
- "Save the histories from `savehist-history-variables' to `savehist-file'.
-Unbound symbols referenced in `savehist-history-variables' are ignored.
+ "Save the values of minibuffer history variables.
+Unbound symbols referenced in `savehist-additional-variables' are ignored.
If AUTO-SAVE is non-nil, compare the saved contents to the one last saved,
and don't save the buffer if they are the same."
(interactive)
(insert
(format ";; -*- mode: emacs-lisp; coding: %s -*-\n" savehist-coding-system)
";; Minibuffer history file, automatically generated by `savehist'.\n\n")
+ (run-hooks 'savehist-save-hook)
(let ((print-length nil)
(print-string-length nil)
(print-level nil)
(print-readably t)
(print-quoted t))
- (dolist (sym savehist-history-variables)
- (when (boundp sym)
- (let ((value (savehist-process-for-saving (symbol-value sym))))
- (prin1 `(setq ,sym ',value) (current-buffer))
- (insert ?\n)))))
+ ;; Save the minibuffer histories, along with the value of
+ ;; savehist-minibuffer-history-variables itself.
+ (when savehist-save-minibuffer-history
+ (prin1 `(setq savehist-minibuffer-history-variables
+ ',savehist-minibuffer-history-variables)
+ (current-buffer))
+ (insert ?\n)
+ (dolist (symbol savehist-minibuffer-history-variables)
+ (when (boundp symbol)
+ (let ((value (savehist-trim-history (symbol-value symbol))))
+ (when value ; don't save empty histories
+ (prin1 `(setq ,symbol ',value) (current-buffer))
+ (insert ?\n))))))
+ ;; Save the additional variables.
+ (dolist (symbol savehist-additional-variables)
+ (when (boundp symbol)
+ (let ((value (symbol-value symbol)))
+ (when (savehist-printable value)
+ (prin1 `(setq ,symbol ',value) (current-buffer))
+ (insert ?\n))))))
;; If autosaving, avoid writing if nothing has changed since the
;; last write.
(let ((checksum (md5 (current-buffer) nil nil savehist-no-conversion)))
(unless (and auto-save (equal checksum savehist-last-checksum))
;; Set file-precious-flag when saving the buffer because we
;; don't want a half-finished write ruining the entire
- ;; history. (Remember that this is run from a timer and from
- ;; kill-emacs-hook.)
+ ;; history. Remember that this is run from a timer and from
+ ;; kill-emacs-hook, and also that multiple Emacs instances
+ ;; could write to this file at once.
(let ((file-precious-flag t)
(coding-system-for-write savehist-coding-system))
(write-region (point-min) (point-max) savehist-file nil
(unless (interactive-p) 'quiet)))
- (when savehist-modes
- (set-file-modes savehist-file savehist-modes))
+ (when savehist-file-modes
+ (set-file-modes savehist-file savehist-file-modes))
(setq savehist-last-checksum checksum)))))
(defun savehist-autosave ()
- "Save the minibuffer history if it has been modified since the last save."
- (savehist-save t))
-
-(defun savehist-process-for-saving (value)
- ;; Process VALUE for saving to file. If it is a list, retain only
- ;; the first `savehist-length' values and prune non-printable ones.
- ;; If VALUE is not a list, return it as-is if it is printable and
- ;; nil otherwise.
- (cond
- ((listp value)
- (when (and savehist-length (> (length value) savehist-length))
- (setq value (subseq value 0 savehist-length)))
- (delete-if-not #'savehist-printable value))
- ((savehist-printable value) value)
- (t nil)))
+ "Save the minibuffer history if it has been modified since the last save.
+Does nothing if `savehist-mode' is off."
+ (when savehist-mode
+ (savehist-save t)))
+
+(defun savehist-trim-history (value)
+ "Retain only the first `history-length' items in VALUE.
+Only used under XEmacs, which doesn't (yet) implement automatic
+trimming of history lists to `history-length' items."
+ (if (and (featurep 'xemacs)
+ (natnump history-length)
+ (> (length value) history-length))
+ ;; Equivalent to `(subseq value 0 history-length)', but doesn't
+ ;; need cl-extra at run-time.
+ (loop repeat history-length collect (pop value))
+ value))
(defun savehist-printable (value)
- "Returns non-nil if VALUE is printable."
- ;; Quick response for oft-encountered types known to be printable.
+ "Return non-nil if VALUE is printable."
(cond
+ ;; Quick response for oft-encountered types known to be printable.
((stringp value))
((numberp value))
((symbolp value))
(t
;; For others, check explicitly.
- (condition-case nil
- (let ((print-readably t)
- (print-level nil)
- (chars ()))
- ;; Print the value into a string...
- (prin1 value (lambda (char) (push char chars)))
+ (with-temp-buffer
+ (condition-case nil
+ (let ((print-readably t) (print-level nil))
+ ;; Print the value into a buffer...
+ (prin1 value (current-buffer))
;; ...and attempt to read it.
- (read (apply #'string (nreverse chars)))
+ (read (point-min-marker))
;; The attempt worked: the object is printable.
t)
- ;; The attempt failed: the object is not printable.
- (error nil)))))
+ ;; The attempt failed: the object is not printable.
+ (error nil))))))
+
+(defun savehist-minibuffer-hook ()
+ (unless (or (eq minibuffer-history-variable t)
+ ;; XEmacs sets minibuffer-history-variable to t to mean "no
+ ;; history is being recorded".
+ (memq minibuffer-history-variable savehist-ignored-variables))
+ (add-to-list 'savehist-minibuffer-history-variables
+ minibuffer-history-variable)))
(provide 'savehist)
+\f
+;; arch-tag: b3ce47f4-c5ad-4ebc-ad02-73aba705cf9f
;;; savehist.el ends here