;;; novice.el --- handling of disabled commands ("novice mode") for Emacs. ;; Copyright (C) 1985, 1986, 1987, 1992, 1993 Free Software Foundation, Inc. ;; Maintainer: FSF ;; Keywords: internal, help ;; This file is part of GNU Emacs. ;; GNU Emacs is free software; you can redistribute it and/or modify ;; it under the terms of the GNU General Public License as published by ;; the Free Software Foundation; either version 2, or (at your option) ;; any later version. ;; GNU Emacs is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; You should have received a copy of the GNU General Public License ;; along with GNU Emacs; see the file COPYING. If not, write to ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. ;;; Commentary: ;; This mode provides a hook which is, by default, attached to various ;; putatively dangerous commands in a (probably futile) attempt to ;; prevent lusers from shooting themselves in the feet. ;;; Code: ;; This function is called (by autoloading) ;; to handle any disabled command. ;; The command is found in this-command ;; and the keys are returned by (this-command-keys). ;;;###autoload ;(setq disabled-command-hook 'disabled-command-hook) ;;;###autoload (defun disabled-command-hook (&rest ignore) (let (char) (save-window-excursion (with-output-to-temp-buffer "*Help*" (if (or (equal (this-command-keys) []) ;lemacs kludge (eq (event-to-character (aref (this-command-keys) 0)) ?\r)) (princ "You have invoked the disabled command ") (princ "You have typed ") (princ (key-description (this-command-keys))) (princ ", invoking disabled command ")) (princ this-command) (princ ":\n") ;; Print any special message saying why the command is disabled. (if (stringp (get this-command 'disabled)) (princ (get this-command 'disabled))) (princ (or (condition-case () (documentation this-command) (error nil)) "<< not documented >>")) ;; Keep only the first paragraph of the documentation. (save-excursion (set-buffer "*Help*") (goto-char (point-min)) (if (search-forward "\n\n" nil t) (delete-region (1- (point)) (point-max)) (goto-char (point-max)))) (princ "\n\n") (princ "You can now type Space to try the command just this once, but leave it disabled, Y to try it and enable it (no questions if you use it again), N to do nothing (command remains disabled).")) (message "Type y, n or Space: ") (let ((cursor-in-echo-area t)) (while (not (memq (setq char (event-to-character (next-command-event))) '(? ?y ?n ?Y ?N))) (ding nil 'y-or-n-p) (discard-input) (message "Please type y, n or Space: ")))) (message nil) (setq char (downcase char)) (if (= char ?y) (if (y-or-n-p "Enable command for future editing sessions also? ") (enable-command this-command) (put this-command 'disabled nil))) (if (/= char ?n) (call-interactively this-command)))) ;;;###autoload (defun enable-command (command) "Allow COMMAND to be executed without special confirmation from now on. The user's .emacs file is altered so that this will apply to future sessions." (interactive "CEnable command: ") (put command 'disabled nil) (save-excursion (set-buffer (find-file-noselect (substitute-in-file-name "~/.emacs"))) (goto-char (point-min)) (if (search-forward (concat "(put '" (symbol-name command) " ") nil t) (delete-region (progn (beginning-of-line) (point)) (progn (forward-line 1) (point))) ;; Must have been disabled by default. (goto-char (point-max)) (insert "\n(put '" (symbol-name command) " 'disabled nil)\n")) (save-buffer))) ;;;###autoload (defun disable-command (command) "Require special confirmation to execute COMMAND from now on. The user's .emacs file is altered so that this will apply to future sessions." (interactive "CDisable command: ") (put command 'disabled t) (save-excursion (set-buffer (find-file-noselect (substitute-in-file-name "~/.emacs"))) (goto-char (point-min)) (if (search-forward (concat "(put '" (symbol-name command) " ") nil t) (delete-region (progn (beginning-of-line) (point)) (progn (forward-line 1) (point)))) (goto-char (point-max)) (insert "(put '" (symbol-name command) " 'disabled t)\n") (save-buffer))) ;;; novice.el ends here