mirror of
https://git.savannah.gnu.org/git/emacs.git
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980 lines
37 KiB
EmacsLisp
980 lines
37 KiB
EmacsLisp
;;; help.el --- help commands for Emacs
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;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001, 2002,
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;; 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
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;; Maintainer: FSF
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;; Keywords: help, internal
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;; This file is part of GNU Emacs.
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;; GNU Emacs is free software; you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation; either version 2, or (at your option)
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;; any later version.
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;; GNU Emacs is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;; You should have received a copy of the GNU General Public License
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;; along with GNU Emacs; see the file COPYING. If not, write to the
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;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
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;; Boston, MA 02110-1301, USA.
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;;; Commentary:
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;; This code implements GNU Emacs' on-line help system, the one invoked by
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;; `M-x help-for-help'.
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;;; Code:
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;; Get the macro make-help-screen when this is compiled,
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;; or run interpreted, but not when the compiled code is loaded.
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(eval-when-compile (require 'help-macro))
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;; This makes `with-output-to-temp-buffer' buffers use `help-mode'.
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(add-hook 'temp-buffer-setup-hook 'help-mode-setup)
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(add-hook 'temp-buffer-show-hook 'help-mode-finish)
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(defvar help-map
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(let ((map (make-sparse-keymap)))
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(define-key map (char-to-string help-char) 'help-for-help)
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(define-key map [help] 'help-for-help)
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(define-key map [f1] 'help-for-help)
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(define-key map "." 'display-local-help)
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(define-key map "?" 'help-for-help)
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(define-key map "\C-c" 'describe-copying)
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(define-key map "\C-d" 'describe-distribution)
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(define-key map "\C-e" 'view-emacs-problems)
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(define-key map "\C-f" 'view-emacs-FAQ)
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(define-key map "\C-m" 'view-order-manuals)
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(define-key map "\C-n" 'view-emacs-news)
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(define-key map "\C-p" 'describe-project)
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(define-key map "\C-t" 'view-todo)
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(define-key map "\C-w" 'describe-no-warranty)
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;; This does not fit the pattern, but it is natural given the C-\ command.
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(define-key map "\C-\\" 'describe-input-method)
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(define-key map "C" 'describe-coding-system)
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(define-key map "F" 'Info-goto-emacs-command-node)
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(define-key map "I" 'describe-input-method)
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(define-key map "K" 'Info-goto-emacs-key-command-node)
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(define-key map "L" 'describe-language-environment)
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(define-key map "S" 'info-lookup-symbol)
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(define-key map "a" 'apropos-command)
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(define-key map "b" 'describe-bindings)
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(define-key map "c" 'describe-key-briefly)
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(define-key map "d" 'apropos-documentation)
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(define-key map "e" 'view-echo-area-messages)
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(define-key map "f" 'describe-function)
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(define-key map "h" 'view-hello-file)
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(define-key map "i" 'info)
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(define-key map "4i" 'info-other-window)
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(define-key map "k" 'describe-key)
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(define-key map "l" 'view-lossage)
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(define-key map "m" 'describe-mode)
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(define-key map "n" 'view-emacs-news)
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(define-key map "p" 'finder-by-keyword)
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(define-key map "r" 'info-emacs-manual)
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(define-key map "s" 'describe-syntax)
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(define-key map "t" 'help-with-tutorial)
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(define-key map "w" 'where-is)
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(define-key map "v" 'describe-variable)
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(define-key map "q" 'help-quit)
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map)
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"Keymap for characters following the Help key.")
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(define-key global-map (char-to-string help-char) 'help-command)
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(define-key global-map [help] 'help-command)
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(define-key global-map [f1] 'help-command)
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(fset 'help-command help-map)
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(autoload 'finder-by-keyword "finder"
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"Find packages matching a given keyword." t)
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;; insert-button makes the action nil if it is not store somewhere
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(defvar help-button-cache nil)
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(defun help-quit ()
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"Just exit from the Help command's command loop."
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(interactive)
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nil)
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(defvar help-return-method nil
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"What to do to \"exit\" the help buffer.
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This is a list
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(WINDOW . t) delete the selected window (and possibly its frame,
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see `quit-window' and `View-quit'), go to WINDOW.
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(WINDOW . quit-window) do quit-window, then select WINDOW.
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(WINDOW BUF START POINT) display BUF at START, POINT, then select WINDOW.")
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(defun print-help-return-message (&optional function)
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"Display or return message saying how to restore windows after help command.
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This function assumes that `standard-output' is the help buffer.
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It computes a message, and applies the optional argument FUNCTION to it.
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If FUNCTION is nil, it applies `message', thus displaying the message.
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In addition, this function sets up `help-return-method', which see, that
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specifies what to do when the user exits the help buffer."
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(and (not (get-buffer-window standard-output))
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(let ((first-message
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(cond ((or
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pop-up-frames
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(special-display-p (buffer-name standard-output)))
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(setq help-return-method (cons (selected-window) t))
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;; If the help output buffer is a special display buffer,
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;; don't say anything about how to get rid of it.
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;; First of all, the user will do that with the window
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;; manager, not with Emacs.
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;; Secondly, the buffer has not been displayed yet,
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;; so we don't know whether its frame will be selected.
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nil)
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(display-buffer-reuse-frames
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(setq help-return-method (cons (selected-window)
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'quit-window))
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nil)
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((not (one-window-p t))
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(setq help-return-method
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(cons (selected-window) 'quit-window))
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"Type \\[display-buffer] RET to restore the other window.")
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(pop-up-windows
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(setq help-return-method (cons (selected-window) t))
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"Type \\[delete-other-windows] to remove help window.")
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(t
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(setq help-return-method
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(list (selected-window) (window-buffer)
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(window-start) (window-point)))
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"Type \\[switch-to-buffer] RET to remove help window."))))
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(funcall (or function 'message)
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(concat
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(if first-message
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(substitute-command-keys first-message))
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(if first-message " ")
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;; If the help buffer will go in a separate frame,
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;; it's no use mentioning a command to scroll, so don't.
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(if (or pop-up-windows
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(special-display-p (buffer-name standard-output)))
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nil
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(if (same-window-p (buffer-name standard-output))
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;; Say how to scroll this window.
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(substitute-command-keys
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"\\[scroll-up] to scroll the help.")
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;; Say how to scroll some other window.
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(substitute-command-keys
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"\\[scroll-other-window] to scroll the help."))))))))
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;; So keyboard macro definitions are documented correctly
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(fset 'defining-kbd-macro (symbol-function 'start-kbd-macro))
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(defalias 'help 'help-for-help-internal)
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;; find-function can find this.
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(defalias 'help-for-help 'help-for-help-internal)
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;; It can't find this, but nobody will look.
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(make-help-screen help-for-help-internal
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"a b c C e f F i I k C-k l L m p r s t v w C-c C-d C-f C-n C-p C-t C-w . or ? :"
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"You have typed %THIS-KEY%, the help character. Type a Help option:
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\(Use SPC or DEL to scroll through this text. Type \\<help-map>\\[help-quit] to exit the Help command.)
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a command-apropos. Type a list of words or a regexp; it shows a list of
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commands whose names match. See also the apropos command.
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b describe-bindings. Display a table of all key bindings.
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c describe-key-briefly. Type a key sequence;
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it displays the command name run by that key sequence.
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C describe-coding-system. Type the name of the coding system to describe,
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or just RET to describe the ones currently in use.
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d apropos-documentation. Type a pattern (a list of words or a regexp), and
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it shows a list of functions, variables, and other items whose
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documentation matches that pattern. See also the apropos command.
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e view-echo-area-messages. Go to the buffer that logs echo-area messages.
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f describe-function. Type a function name and you see its documentation.
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F Info-goto-emacs-command-node. Type a command name;
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it goes to the on-line manual's section that describes the command.
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h Display the HELLO file which illustrates various scripts.
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i info. The Info documentation reader: read on-line manuals.
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I describe-input-method. Describe a specific input method (if you type
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its name) or the current input method (if you type just RET).
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k describe-key. Type a key sequence;
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it displays the full documentation for that key sequence.
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K Info-goto-emacs-key-command-node. Type a key sequence;
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it goes to the on-line manual's section that describes
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the command bound to that key.
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l view-lossage. Show last 100 characters you typed.
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L describe-language-environment. This describes either a
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specific language environment (if you type its name)
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or the current language environment (if you type just RET).
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m describe-mode. Display documentation of current minor modes,
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and the current major mode, including their special commands.
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n view-emacs-news. Display news of recent Emacs changes.
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p finder-by-keyword. Find packages matching a given topic keyword.
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r info-emacs-manual. Display the Emacs manual in Info mode.
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s describe-syntax. Display contents of syntax table, plus explanations.
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S info-lookup-symbol. Type a symbol; it goes to that symbol in the
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on-line manual for the programming language used in this buffer.
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t help-with-tutorial. Select the Emacs learn-by-doing tutorial.
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v describe-variable. Type name of a variable;
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it displays the variable's documentation and value.
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w where-is. Type a command name; it displays which keystrokes
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invoke that command.
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. display-local-help. Display any available local help at point
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in the echo area.
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C-c Display Emacs copying permission (GNU General Public License).
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C-d Display Emacs ordering information.
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C-e Display info about Emacs problems.
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C-f Display the Emacs FAQ.
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C-m Display how to order printed Emacs manuals.
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C-n Display news of recent Emacs changes.
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C-p Display information about the GNU project.
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C-t Display the Emacs TODO list.
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C-w Display information on absence of warranty for GNU Emacs."
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help-map)
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(defun function-called-at-point ()
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"Return a function around point or else called by the list containing point.
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If that doesn't give a function, return nil."
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(or (with-syntax-table emacs-lisp-mode-syntax-table
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(or (condition-case ()
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(save-excursion
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(or (not (zerop (skip-syntax-backward "_w")))
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(eq (char-syntax (following-char)) ?w)
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(eq (char-syntax (following-char)) ?_)
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(forward-sexp -1))
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(skip-chars-forward "'")
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(let ((obj (read (current-buffer))))
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(and (symbolp obj) (fboundp obj) obj)))
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(error nil))
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(condition-case ()
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(save-excursion
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(save-restriction
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(narrow-to-region (max (point-min)
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(- (point) 1000)) (point-max))
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;; Move up to surrounding paren, then after the open.
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(backward-up-list 1)
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(forward-char 1)
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;; If there is space here, this is probably something
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;; other than a real Lisp function call, so ignore it.
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(if (looking-at "[ \t]")
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(error "Probably not a Lisp function call"))
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(let ((obj (read (current-buffer))))
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(and (symbolp obj) (fboundp obj) obj))))
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(error nil))))
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(let* ((str (find-tag-default))
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(sym (if str (intern-soft str))))
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(if (and sym (fboundp sym))
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sym
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(save-match-data
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(when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str))
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(setq sym (intern-soft (match-string 1 str)))
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(and (fboundp sym) sym)))))))
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;;; `User' help functions
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(defun describe-distribution ()
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"Display info on how to obtain the latest version of GNU Emacs."
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(interactive)
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(view-file (expand-file-name "DISTRIB" data-directory)))
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(defun describe-copying ()
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"Display info on how you may redistribute copies of GNU Emacs."
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(interactive)
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(view-file (expand-file-name "COPYING" data-directory))
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(goto-char (point-min)))
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(defun describe-project ()
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"Display info on the GNU project."
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(interactive)
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(view-file (expand-file-name "THE-GNU-PROJECT" data-directory))
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(goto-char (point-min)))
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(defun describe-no-warranty ()
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"Display info on all the kinds of warranty Emacs does NOT have."
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(interactive)
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(describe-copying)
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(let (case-fold-search)
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(search-forward "NO WARRANTY")
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(recenter 0)))
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(defun describe-prefix-bindings ()
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"Describe the bindings of the prefix used to reach this command.
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The prefix described consists of all but the last event
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of the key sequence that ran this command."
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(interactive)
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(let ((key (this-command-keys)))
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(describe-bindings
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(if (stringp key)
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(substring key 0 (1- (length key)))
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(let ((prefix (make-vector (1- (length key)) nil))
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(i 0))
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(while (< i (length prefix))
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(aset prefix i (aref key i))
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(setq i (1+ i)))
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prefix)))))
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;; Make C-h after a prefix, when not specifically bound,
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;; run describe-prefix-bindings.
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(setq prefix-help-command 'describe-prefix-bindings)
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(defun view-emacs-news (&optional version)
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"Display info on recent changes to Emacs.
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With argument, display info only for the selected version."
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(interactive "P")
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(unless version
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(setq version emacs-major-version))
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(when (consp version)
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(let* ((all-versions
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(let (res)
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(mapcar
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(lambda (file)
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(with-temp-buffer
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(insert-file-contents
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(expand-file-name file data-directory))
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(while (re-search-forward
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(if (member file '("NEWS.18" "NEWS.1-17"))
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"Changes in \\(?:Emacs\\|version\\)?[ \t]*\\([0-9]+\\(?:\\.[0-9]+\\)?\\)"
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"^\* [^0-9\n]*\\([0-9]+\\.[0-9]+\\)") nil t)
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(setq res (cons (match-string-no-properties 1) res)))))
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(cons "NEWS"
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(directory-files data-directory nil
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"^NEWS\\.[0-9][-0-9]*$" nil)))
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(sort (delete-dups res) (lambda (a b) (string< b a)))))
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(current (car all-versions)))
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(setq version (completing-read
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(format "Read NEWS for the version (default %s): " current)
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all-versions nil nil nil nil current))
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(if (integerp (string-to-number version))
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(setq version (string-to-number version))
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(unless (or (member version all-versions)
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(<= (string-to-number version) (string-to-number current)))
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(error "No news about version %s" version)))))
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(when (integerp version)
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(cond ((<= version 12)
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(setq version (format "1.%d" version)))
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((<= version 18)
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(setq version (format "%d" version)))
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((> version emacs-major-version)
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(error "No news about Emacs %d (yet)" version))))
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(let* ((vn (if (stringp version)
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(string-to-number version)
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version))
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(file (cond
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((>= vn emacs-major-version) "NEWS")
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((< vn 18) "NEWS.1-17")
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(t (format "NEWS.%d" vn))))
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res)
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(view-file (expand-file-name file data-directory))
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(widen)
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(goto-char (point-min))
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(when (stringp version)
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(when (re-search-forward
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(concat (if (< vn 19)
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"Changes in Emacs[ \t]*"
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"^\* [^0-9\n]*") version "$")
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nil t)
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(beginning-of-line)
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(narrow-to-region
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(point)
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(save-excursion
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(while (and (setq res
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(re-search-forward
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(if (< vn 19)
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"Changes in \\(?:Emacs\\|version\\)?[ \t]*\\([0-9]+\\(?:\\.[0-9]+\\)?\\)"
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"^\* [^0-9\n]*\\([0-9]+\\.[0-9]+\\)") nil t))
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(equal (match-string-no-properties 1) version)))
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(or res (goto-char (point-max)))
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(beginning-of-line)
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(point)))))))
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(defun view-todo (&optional arg)
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"Display the Emacs TODO list."
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(interactive "P")
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(view-file (expand-file-name "TODO" data-directory)))
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(defun view-echo-area-messages ()
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"View the log of recent echo-area messages: the `*Messages*' buffer.
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The number of messages retained in that buffer
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is specified by the variable `message-log-max'."
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(interactive)
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(switch-to-buffer (get-buffer-create "*Messages*")))
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(defun view-order-manuals ()
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"Display the Emacs ORDERS file."
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(interactive)
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(view-file (expand-file-name "ORDERS" data-directory))
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(goto-address))
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(defun view-emacs-FAQ ()
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"Display the Emacs Frequently Asked Questions (FAQ) file."
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(interactive)
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;; (find-file-read-only (expand-file-name "FAQ" data-directory))
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(info "(efaq)"))
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(defun view-emacs-problems ()
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"Display info on known problems with Emacs and possible workarounds."
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(interactive)
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(view-file (expand-file-name "PROBLEMS" data-directory)))
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(defun view-lossage ()
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"Display last 100 input keystrokes.
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To record all your input on a file, use `open-dribble-file'."
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(interactive)
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(help-setup-xref (list #'view-lossage) (interactive-p))
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(with-output-to-temp-buffer (help-buffer)
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(princ (mapconcat (lambda (key)
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(if (or (integerp key) (symbolp key) (listp key))
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(single-key-description key)
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(prin1-to-string key nil)))
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(recent-keys)
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" "))
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(with-current-buffer standard-output
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(goto-char (point-min))
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(while (progn (move-to-column 50) (not (eobp)))
|
||
(when (search-forward " " nil t)
|
||
(delete-char -1))
|
||
(insert "\n")))
|
||
(print-help-return-message)))
|
||
|
||
|
||
;; Key bindings
|
||
|
||
(defun describe-bindings (&optional prefix buffer)
|
||
"Show a list of all defined keys, and their definitions.
|
||
We put that list in a buffer, and display the buffer.
|
||
|
||
The optional argument PREFIX, if non-nil, should be a key sequence;
|
||
then we display only bindings that start with that prefix.
|
||
The optional argument BUFFER specifies which buffer's bindings
|
||
to display (default, the current buffer). BUFFER can be a buffer
|
||
or a buffer name."
|
||
(interactive)
|
||
(or buffer (setq buffer (current-buffer)))
|
||
(help-setup-xref (list #'describe-bindings prefix buffer) (interactive-p))
|
||
(with-current-buffer buffer
|
||
(describe-bindings-internal nil prefix)))
|
||
|
||
;; This function used to be in keymap.c.
|
||
(defun describe-bindings-internal (&optional menus prefix)
|
||
"Show a list of all defined keys, and their definitions.
|
||
We put that list in a buffer, and display the buffer.
|
||
|
||
The optional argument MENUS, if non-nil, says to mention menu bindings.
|
||
\(Ordinarily these are omitted from the output.)
|
||
The optional argument PREFIX, if non-nil, should be a key sequence;
|
||
then we display only bindings that start with that prefix."
|
||
(interactive)
|
||
(let ((buf (current-buffer)))
|
||
(with-output-to-temp-buffer "*Help*"
|
||
(with-current-buffer standard-output
|
||
(describe-buffer-bindings buf prefix menus)))))
|
||
|
||
(defun where-is (definition &optional insert)
|
||
"Print message listing key sequences that invoke the command DEFINITION.
|
||
Argument is a command definition, usually a symbol with a function definition.
|
||
If INSERT (the prefix arg) is non-nil, insert the message in the buffer."
|
||
(interactive
|
||
(let ((fn (function-called-at-point))
|
||
(enable-recursive-minibuffers t)
|
||
val)
|
||
(setq val (completing-read
|
||
(if fn
|
||
(format "Where is command (default %s): " fn)
|
||
"Where is command: ")
|
||
obarray 'commandp t))
|
||
(list (if (equal val "") fn (intern val)) current-prefix-arg)))
|
||
(unless definition (error "No command"))
|
||
(let ((func (indirect-function definition))
|
||
(defs nil)
|
||
(standard-output (if insert (current-buffer) t)))
|
||
;; In DEFS, find all symbols that are aliases for DEFINITION.
|
||
(mapatoms (lambda (symbol)
|
||
(and (fboundp symbol)
|
||
(not (eq symbol definition))
|
||
(eq func (condition-case ()
|
||
(indirect-function symbol)
|
||
(error symbol)))
|
||
(push symbol defs))))
|
||
;; Look at all the symbols--first DEFINITION,
|
||
;; then its aliases.
|
||
(dolist (symbol (cons definition defs))
|
||
(let* ((remapped (command-remapping symbol))
|
||
(keys (where-is-internal
|
||
symbol overriding-local-map nil nil remapped))
|
||
(keys (mapconcat 'key-description keys ", "))
|
||
string)
|
||
(setq string
|
||
(if insert
|
||
(if (> (length keys) 0)
|
||
(if remapped
|
||
(format "%s (%s) (remapped from %s)"
|
||
keys remapped symbol)
|
||
(format "%s (%s)" keys symbol))
|
||
(format "M-x %s RET" symbol))
|
||
(if (> (length keys) 0)
|
||
(if remapped
|
||
(format "%s is remapped to %s which is on %s"
|
||
symbol remapped keys)
|
||
(format "%s is on %s" symbol keys))
|
||
;; If this is the command the user asked about,
|
||
;; and it is not on any key, say so.
|
||
;; For other symbols, its aliases, say nothing
|
||
;; about them unless they are on keys.
|
||
(if (eq symbol definition)
|
||
(format "%s is not on any key" symbol)))))
|
||
(when string
|
||
(unless (eq symbol definition)
|
||
(princ ";\n its alias "))
|
||
(princ string)))))
|
||
nil)
|
||
|
||
(defun help-key-description (key untranslated)
|
||
(let ((string (key-description key)))
|
||
(if (or (not untranslated)
|
||
(and (eq (aref untranslated 0) ?\e) (not (eq (aref key 0) ?\e))))
|
||
string
|
||
(let ((otherstring (key-description untranslated)))
|
||
(if (equal string otherstring)
|
||
string
|
||
(format "%s (translated from %s)" string otherstring))))))
|
||
|
||
(defun describe-key-briefly (&optional key insert untranslated)
|
||
"Print the name of the function KEY invokes. KEY is a string.
|
||
If INSERT (the prefix arg) is non-nil, insert the message in the buffer.
|
||
If non-nil, UNTRANSLATED is a vector of the untranslated events.
|
||
It can also be a number in which case the untranslated events from
|
||
the last key hit are used.
|
||
|
||
If KEY is a menu item or a tool-bar button that is disabled, this command
|
||
temporarily enables it to allow getting help on disabled items and buttons."
|
||
(interactive
|
||
(let ((enable-disabled-menus-and-buttons t)
|
||
(cursor-in-echo-area t)
|
||
saved-yank-menu)
|
||
(unwind-protect
|
||
(let (key)
|
||
;; If yank-menu is empty, populate it temporarily, so that
|
||
;; "Select and Paste" menu can generate a complete event.
|
||
(when (null (cdr yank-menu))
|
||
(setq saved-yank-menu (copy-sequence yank-menu))
|
||
(menu-bar-update-yank-menu "(any string)" nil))
|
||
(setq key (read-key-sequence "Describe key (or click or menu item): "))
|
||
;; If KEY is a down-event, read and discard the
|
||
;; corresponding up-event. Note that there are also
|
||
;; down-events on scroll bars and mode lines: the actual
|
||
;; event then is in the second element of the vector.
|
||
(and (vectorp key)
|
||
(let ((last-idx (1- (length key))))
|
||
(and (eventp (aref key last-idx))
|
||
(memq 'down (event-modifiers (aref key last-idx)))))
|
||
(read-event))
|
||
(list
|
||
key
|
||
(if current-prefix-arg (prefix-numeric-value current-prefix-arg))
|
||
1))
|
||
;; Put yank-menu back as it was, if we changed it.
|
||
(when saved-yank-menu
|
||
(setq yank-menu (copy-sequence saved-yank-menu))
|
||
(fset 'yank-menu (cons 'keymap yank-menu))))))
|
||
(if (numberp untranslated)
|
||
(setq untranslated (this-single-command-raw-keys)))
|
||
(let* ((event (if (and (symbolp (aref key 0))
|
||
(> (length key) 1)
|
||
(consp (aref key 1)))
|
||
(aref key 1)
|
||
(aref key 0)))
|
||
(modifiers (event-modifiers event))
|
||
(standard-output (if insert (current-buffer) t))
|
||
(mouse-msg (if (or (memq 'click modifiers) (memq 'down modifiers)
|
||
(memq 'drag modifiers)) " at that spot" ""))
|
||
(defn (key-binding key t))
|
||
key-desc)
|
||
;; Handle the case where we faked an entry in "Select and Paste" menu.
|
||
(if (and (eq defn nil)
|
||
(stringp (aref key (1- (length key))))
|
||
(eq (key-binding (substring key 0 -1)) 'yank-menu))
|
||
(setq defn 'menu-bar-select-yank))
|
||
;; Don't bother user with strings from (e.g.) the select-paste menu.
|
||
(if (stringp (aref key (1- (length key))))
|
||
(aset key (1- (length key)) "(any string)"))
|
||
(if (and (> (length untranslated) 0)
|
||
(stringp (aref untranslated (1- (length untranslated)))))
|
||
(aset untranslated (1- (length untranslated)) "(any string)"))
|
||
;; Now describe the key, perhaps as changed.
|
||
(setq key-desc (help-key-description key untranslated))
|
||
(if (or (null defn) (integerp defn) (equal defn 'undefined))
|
||
(princ (format "%s%s is undefined" key-desc mouse-msg))
|
||
(princ (format "%s%s runs the command %S" key-desc mouse-msg defn)))))
|
||
|
||
(defun describe-key (&optional key untranslated up-event)
|
||
"Display documentation of the function invoked by KEY.
|
||
KEY can be any kind of a key sequence; it can include keyboard events,
|
||
mouse events, and/or menu events. When calling from a program,
|
||
pass KEY as a string or a vector.
|
||
|
||
If non-nil, UNTRANSLATED is a vector of the corresponding untranslated events.
|
||
It can also be a number, in which case the untranslated events from
|
||
the last key sequence entered are used.
|
||
UP-EVENT is the up-event that was discarded by reading KEY, or nil.
|
||
|
||
If KEY is a menu item or a tool-bar button that is disabled, this command
|
||
temporarily enables it to allow getting help on disabled items and buttons."
|
||
(interactive
|
||
(let ((enable-disabled-menus-and-buttons t)
|
||
(cursor-in-echo-area t)
|
||
saved-yank-menu)
|
||
(unwind-protect
|
||
(let (key)
|
||
;; If yank-menu is empty, populate it temporarily, so that
|
||
;; "Select and Paste" menu can generate a complete event.
|
||
(when (null (cdr yank-menu))
|
||
(setq saved-yank-menu (copy-sequence yank-menu))
|
||
(menu-bar-update-yank-menu "(any string)" nil))
|
||
(setq key (read-key-sequence "Describe key (or click or menu item): "))
|
||
(list
|
||
key
|
||
(prefix-numeric-value current-prefix-arg)
|
||
;; If KEY is a down-event, read and include the
|
||
;; corresponding up-event. Note that there are also
|
||
;; down-events on scroll bars and mode lines: the actual
|
||
;; event then is in the second element of the vector.
|
||
(and (vectorp key)
|
||
(let ((last-idx (1- (length key))))
|
||
(and (eventp (aref key last-idx))
|
||
(memq 'down (event-modifiers (aref key last-idx)))))
|
||
(or (and (eventp (aref key 0))
|
||
(memq 'down (event-modifiers (aref key 0)))
|
||
;; However, for the C-down-mouse-2 popup
|
||
;; menu, there is no subsequent up-event. In
|
||
;; this case, the up-event is the next
|
||
;; element in the supplied vector.
|
||
(= (length key) 1))
|
||
(and (> (length key) 1)
|
||
(eventp (aref key 1))
|
||
(memq 'down (event-modifiers (aref key 1)))))
|
||
(read-event))))
|
||
;; Put yank-menu back as it was, if we changed it.
|
||
(when saved-yank-menu
|
||
(setq yank-menu (copy-sequence saved-yank-menu))
|
||
(fset 'yank-menu (cons 'keymap yank-menu))))))
|
||
(if (numberp untranslated)
|
||
(setq untranslated (this-single-command-raw-keys)))
|
||
(let* ((event (aref key (if (and (symbolp (aref key 0))
|
||
(> (length key) 1)
|
||
(consp (aref key 1)))
|
||
1
|
||
0)))
|
||
(modifiers (event-modifiers event))
|
||
(mouse-msg (if (or (memq 'click modifiers) (memq 'down modifiers)
|
||
(memq 'drag modifiers)) " at that spot" ""))
|
||
(defn (key-binding key t))
|
||
defn-up defn-up-tricky ev-type
|
||
mouse-1-remapped mouse-1-tricky)
|
||
|
||
;; Handle the case where we faked an entry in "Select and Paste" menu.
|
||
(when (and (eq defn nil)
|
||
(stringp (aref key (1- (length key))))
|
||
(eq (key-binding (substring key 0 -1)) 'yank-menu))
|
||
(setq defn 'menu-bar-select-yank))
|
||
(if (or (null defn) (integerp defn) (equal defn 'undefined))
|
||
(message "%s%s is undefined"
|
||
(help-key-description key untranslated) mouse-msg)
|
||
(help-setup-xref (list #'describe-function defn) (interactive-p))
|
||
;; Don't bother user with strings from (e.g.) the select-paste menu.
|
||
(when (stringp (aref key (1- (length key))))
|
||
(aset key (1- (length key)) "(any string)"))
|
||
(when (and untranslated
|
||
(stringp (aref untranslated (1- (length untranslated)))))
|
||
(aset untranslated (1- (length untranslated))
|
||
"(any string)"))
|
||
;; Need to do this before erasing *Help* buffer in case event
|
||
;; is a mouse click in an existing *Help* buffer.
|
||
(when up-event
|
||
(setq ev-type (event-basic-type up-event))
|
||
(let ((sequence (vector up-event)))
|
||
(when (and (eq ev-type 'mouse-1)
|
||
mouse-1-click-follows-link
|
||
(not (eq mouse-1-click-follows-link 'double))
|
||
(setq mouse-1-remapped
|
||
(mouse-on-link-p (event-start up-event))))
|
||
(setq mouse-1-tricky (and (integerp mouse-1-click-follows-link)
|
||
(> mouse-1-click-follows-link 0)))
|
||
(cond ((stringp mouse-1-remapped)
|
||
(setq sequence mouse-1-remapped))
|
||
((vectorp mouse-1-remapped)
|
||
(setcar up-event (elt mouse-1-remapped 0)))
|
||
(t (setcar up-event 'mouse-2))))
|
||
(setq defn-up (key-binding sequence nil nil (event-start up-event)))
|
||
(when mouse-1-tricky
|
||
(setq sequence (vector up-event))
|
||
(aset sequence 0 'mouse-1)
|
||
(setq defn-up-tricky (key-binding sequence nil nil (event-start up-event))))))
|
||
(with-output-to-temp-buffer (help-buffer)
|
||
(princ (help-key-description key untranslated))
|
||
(princ (format "\
|
||
%s runs the command %S
|
||
which is "
|
||
mouse-msg defn))
|
||
(describe-function-1 defn)
|
||
(when up-event
|
||
(unless (or (null defn-up)
|
||
(integerp defn-up)
|
||
(equal defn-up 'undefined))
|
||
(princ (format "
|
||
|
||
----------------- up-event %s----------------
|
||
|
||
<%S>%s%s runs the command %S
|
||
which is "
|
||
(if mouse-1-tricky "(short click) " "")
|
||
ev-type mouse-msg
|
||
(if mouse-1-remapped
|
||
" is remapped to <mouse-2>\nwhich" "")
|
||
defn-up))
|
||
(describe-function-1 defn-up))
|
||
(unless (or (null defn-up-tricky)
|
||
(integerp defn-up-tricky)
|
||
(eq defn-up-tricky 'undefined))
|
||
(princ (format "
|
||
|
||
----------------- up-event (long click) ----------------
|
||
|
||
Pressing <%S>%s for longer than %d milli-seconds
|
||
runs the command %S
|
||
which is "
|
||
ev-type mouse-msg
|
||
mouse-1-click-follows-link
|
||
defn-up-tricky))
|
||
(describe-function-1 defn-up-tricky)))
|
||
(print-help-return-message)))))
|
||
|
||
(defun describe-mode (&optional buffer)
|
||
"Display documentation of current major mode and minor modes.
|
||
A brief summary of the minor modes comes first, followed by the
|
||
major mode description. This is followed by detailed
|
||
descriptions of the minor modes, each on a separate page.
|
||
|
||
For this to work correctly for a minor mode, the mode's indicator
|
||
variable \(listed in `minor-mode-alist') must also be a function
|
||
whose documentation describes the minor mode."
|
||
(interactive "@")
|
||
(unless buffer (setq buffer (current-buffer)))
|
||
(help-setup-xref (list #'describe-mode buffer)
|
||
(interactive-p))
|
||
;; For the sake of help-do-xref and help-xref-go-back,
|
||
;; don't switch buffers before calling `help-buffer'.
|
||
(with-output-to-temp-buffer (help-buffer)
|
||
(with-current-buffer buffer
|
||
(let (minor-modes)
|
||
;; Older packages do not register in minor-mode-list but only in
|
||
;; minor-mode-alist.
|
||
(dolist (x minor-mode-alist)
|
||
(setq x (car x))
|
||
(unless (memq x minor-mode-list)
|
||
(push x minor-mode-list)))
|
||
;; Find enabled minor mode we will want to mention.
|
||
(dolist (mode minor-mode-list)
|
||
;; Document a minor mode if it is listed in minor-mode-alist,
|
||
;; non-nil, and has a function definition.
|
||
(let ((fmode (or (get mode :minor-mode-function) mode)))
|
||
(and (boundp mode) (symbol-value mode)
|
||
(fboundp fmode)
|
||
(let ((pretty-minor-mode
|
||
(if (string-match "\\(\\(-minor\\)?-mode\\)?\\'"
|
||
(symbol-name fmode))
|
||
(capitalize
|
||
(substring (symbol-name fmode)
|
||
0 (match-beginning 0)))
|
||
fmode)))
|
||
(push (list fmode pretty-minor-mode
|
||
(format-mode-line (assq mode minor-mode-alist)))
|
||
minor-modes)))))
|
||
(setq minor-modes
|
||
(sort minor-modes
|
||
(lambda (a b) (string-lessp (cadr a) (cadr b)))))
|
||
(when minor-modes
|
||
(princ "Enabled minor modes:\n")
|
||
(make-local-variable 'help-button-cache)
|
||
(with-current-buffer standard-output
|
||
(dolist (mode minor-modes)
|
||
(let ((mode-function (nth 0 mode))
|
||
(pretty-minor-mode (nth 1 mode))
|
||
(indicator (nth 2 mode)))
|
||
(add-text-properties 0 (length pretty-minor-mode)
|
||
'(face bold) pretty-minor-mode)
|
||
(save-excursion
|
||
(goto-char (point-max))
|
||
(princ "\n\f\n")
|
||
(push (point-marker) help-button-cache)
|
||
;; Document the minor modes fully.
|
||
(insert pretty-minor-mode)
|
||
(princ (format " minor mode (%s):\n"
|
||
(if (zerop (length indicator))
|
||
"no indicator"
|
||
(format "indicator%s"
|
||
indicator))))
|
||
(princ (documentation mode-function)))
|
||
(insert-button pretty-minor-mode
|
||
'action (car help-button-cache)
|
||
'follow-link t
|
||
'help-echo "mouse-2, RET: show full information")
|
||
(newline)))
|
||
(forward-line -1)
|
||
(fill-paragraph nil)
|
||
(forward-line 1))
|
||
|
||
(princ "\n(Information about these minor modes follows the major mode info.)\n\n"))
|
||
;; Document the major mode.
|
||
(let ((mode mode-name))
|
||
(with-current-buffer standard-output
|
||
(let ((start (point)))
|
||
(insert (format-mode-line mode))
|
||
(add-text-properties start (point) '(face bold)))))
|
||
(princ " mode:\n")
|
||
(princ (documentation major-mode)))
|
||
(print-help-return-message))))
|
||
|
||
|
||
(defun describe-minor-mode (minor-mode)
|
||
"Display documentation of a minor mode given as MINOR-MODE.
|
||
MINOR-MODE can be a minor mode symbol or a minor mode indicator string
|
||
appeared on the mode-line."
|
||
(interactive (list (completing-read
|
||
"Minor mode: "
|
||
(nconc
|
||
(describe-minor-mode-completion-table-for-symbol)
|
||
(describe-minor-mode-completion-table-for-indicator)
|
||
))))
|
||
(if (symbolp minor-mode)
|
||
(setq minor-mode (symbol-name minor-mode)))
|
||
(let ((symbols (describe-minor-mode-completion-table-for-symbol))
|
||
(indicators (describe-minor-mode-completion-table-for-indicator)))
|
||
(cond
|
||
((member minor-mode symbols)
|
||
(describe-minor-mode-from-symbol (intern minor-mode)))
|
||
((member minor-mode indicators)
|
||
(describe-minor-mode-from-indicator minor-mode))
|
||
(t
|
||
(error "No such minor mode: %s" minor-mode)))))
|
||
|
||
;; symbol
|
||
(defun describe-minor-mode-completion-table-for-symbol ()
|
||
;; In order to list up all minor modes, minor-mode-list
|
||
;; is used here instead of minor-mode-alist.
|
||
(delq nil (mapcar 'symbol-name minor-mode-list)))
|
||
(defun describe-minor-mode-from-symbol (symbol)
|
||
"Display documentation of a minor mode given as a symbol, SYMBOL"
|
||
(interactive (list (intern (completing-read
|
||
"Minor mode symbol: "
|
||
(describe-minor-mode-completion-table-for-symbol)))))
|
||
(if (fboundp symbol)
|
||
(describe-function symbol)
|
||
(describe-variable symbol)))
|
||
|
||
;; indicator
|
||
(defun describe-minor-mode-completion-table-for-indicator ()
|
||
(delq nil
|
||
(mapcar (lambda (x)
|
||
(let ((i (format-mode-line x)))
|
||
;; remove first space if existed
|
||
(cond
|
||
((= 0 (length i))
|
||
nil)
|
||
((eq (aref i 0) ?\s)
|
||
(substring i 1))
|
||
(t
|
||
i))))
|
||
minor-mode-alist)))
|
||
(defun describe-minor-mode-from-indicator (indicator)
|
||
"Display documentation of a minor mode specified by INDICATOR.
|
||
If you call this function interactively, you can give indicator which
|
||
is currently activated with completion."
|
||
(interactive (list
|
||
(completing-read
|
||
"Minor mode indicator: "
|
||
(describe-minor-mode-completion-table-for-indicator))))
|
||
(let ((minor-mode (lookup-minor-mode-from-indicator indicator)))
|
||
(if minor-mode
|
||
(describe-minor-mode-from-symbol minor-mode)
|
||
(error "Cannot find minor mode for `%s'" indicator))))
|
||
|
||
(defun lookup-minor-mode-from-indicator (indicator)
|
||
"Return a minor mode symbol from its indicator on the modeline."
|
||
;; remove first space if existed
|
||
(if (and (< 0 (length indicator))
|
||
(eq (aref indicator 0) ?\s))
|
||
(setq indicator (substring indicator 1)))
|
||
(let ((minor-modes minor-mode-alist)
|
||
result)
|
||
(while minor-modes
|
||
(let* ((minor-mode (car (car minor-modes)))
|
||
(anindicator (format-mode-line
|
||
(car (cdr (car minor-modes))))))
|
||
;; remove first space if existed
|
||
(if (and (stringp anindicator)
|
||
(> (length anindicator) 0)
|
||
(eq (aref anindicator 0) ?\s))
|
||
(setq anindicator (substring anindicator 1)))
|
||
(if (equal indicator anindicator)
|
||
(setq result minor-mode
|
||
minor-modes nil)
|
||
(setq minor-modes (cdr minor-modes)))))
|
||
result))
|
||
|
||
|
||
;;; Automatic resizing of temporary buffers.
|
||
|
||
(defcustom temp-buffer-max-height (lambda (buffer) (/ (- (frame-height) 2) 2))
|
||
"Maximum height of a window displaying a temporary buffer.
|
||
This is effective only when Temp Buffer Resize mode is enabled.
|
||
The value is the maximum height (in lines) which `resize-temp-buffer-window'
|
||
will give to a window displaying a temporary buffer.
|
||
It can also be a function to be called to choose the height for such a buffer.
|
||
It gets one argumemt, the buffer, and should return a positive integer."
|
||
:type '(choice integer function)
|
||
:group 'help
|
||
:version "20.4")
|
||
|
||
(define-minor-mode temp-buffer-resize-mode
|
||
"Toggle the mode which makes windows smaller for temporary buffers.
|
||
With prefix argument ARG, turn the resizing of windows displaying temporary
|
||
buffers on if ARG is positive or off otherwise.
|
||
This makes the window the right height for its contents, but never
|
||
more than `temp-buffer-max-height' nor less than `window-min-height'.
|
||
This applies to `help', `apropos' and `completion' buffers, and some others."
|
||
:global t :group 'help
|
||
(if temp-buffer-resize-mode
|
||
;; `help-make-xrefs' may add a `back' button and thus increase the
|
||
;; text size, so `resize-temp-buffer-window' must be run *after* it.
|
||
(add-hook 'temp-buffer-show-hook 'resize-temp-buffer-window 'append)
|
||
(remove-hook 'temp-buffer-show-hook 'resize-temp-buffer-window)))
|
||
|
||
(defun resize-temp-buffer-window ()
|
||
"Resize the current window to fit its contents.
|
||
Will not make it higher than `temp-buffer-max-height' nor smaller than
|
||
`window-min-height'. Do nothing if it is the only window on its frame, if it
|
||
is not as wide as the frame or if some of the window's contents are scrolled
|
||
out of view."
|
||
(unless (or (one-window-p 'nomini)
|
||
(not (pos-visible-in-window-p (point-min)))
|
||
(/= (frame-width) (window-width)))
|
||
(fit-window-to-buffer
|
||
(selected-window)
|
||
(if (functionp temp-buffer-max-height)
|
||
(funcall temp-buffer-max-height (current-buffer))
|
||
temp-buffer-max-height))))
|
||
|
||
|
||
(provide 'help)
|
||
|
||
;; arch-tag: cf427352-27e9-49b7-9a6f-741ebab02423
|
||
;;; help.el ends here
|