(defvar disabled-command-hook 'disabled-command-hook
"Function to call to handle disabled commands.
If nil, the feature is disabled, i.e., all commands work normally.")
(defun disabled-command-hook (&rest ignore)
(let (char)
(save-window-excursion
(with-output-to-temp-buffer "*Help*"
(let ((keys (this-command-keys)))
(if (or (eq (aref keys 0)
(if (stringp keys)
(aref "\M-x" 0)
?\M-x))
(and (>= (length keys) 2)
(eq (aref keys 0) meta-prefix-char)
(eq (aref keys 1) ?x)))
(princ "You have invoked the disabled command ")
(princ "You have typed ")
(princ (key-description keys))
(princ ", invoking disabled command ")))
(princ this-command)
(princ ":\n")
(if (stringp (get this-command 'disabled))
(princ (get this-command 'disabled)))
(save-excursion
(set-buffer "*Help*")
(goto-char (point-max))
(save-excursion
(princ (or (condition-case ()
(documentation this-command)
(error nil))
"<< not documented >>")))
(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),
! to try it and enable all commands in this session, or
N to do nothing (command remains disabled).")
(save-excursion
(set-buffer standard-output)
(help-mode)))
(message "Type y, n, ! or Space: ")
(let ((cursor-in-echo-area t))
(while (not (memq (setq char (downcase (read-char)))
'(?! ? ?y ?n)))
(ding)
(message "Please type y, n, ! or Space: "))))
(if (= char ?!)
(setq disabled-command-hook nil))
(if (= char ?y)
(if (and user-init-file
(not (string= "" user-init-file))
(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))))
(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)
(let ((init-file user-init-file)
(default-init-file
(if (eq system-type 'ms-dos) "~/_emacs" "~/.emacs")))
(when (null init-file)
(if (or (file-exists-p default-init-file)
(and (eq system-type 'windows-nt)
(file-exists-p "~/_emacs")))
(error "Saving settings from \"emacs -q\" would overwrite existing customizations"))
(setq init-file default-init-file)
(if (and (not (file-exists-p init-file))
(eq system-type 'windows-nt)
(file-exists-p "~/_emacs"))
(setq init-file "~/_emacs")))
(save-excursion
(set-buffer (find-file-noselect
(substitute-in-file-name init-file)))
(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 "\n(put '" (symbol-name command) " 'disabled nil)\n")
(save-buffer))))
(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: ")
(if (not (commandp command))
(error "Invalid command name `%s'" command))
(put command 'disabled t)
(let ((init-file user-init-file)
(default-init-file
(if (eq system-type 'ms-dos) "~/_emacs" "~/.emacs")))
(when (null init-file)
(if (or (file-exists-p default-init-file)
(and (eq system-type 'windows-nt)
(file-exists-p "~/_emacs")))
(error "Saving settings from \"emacs -q\" would overwrite existing customizations"))
(setq init-file default-init-file)
(if (and (not (file-exists-p init-file))
(eq system-type 'windows-nt)
(file-exists-p "~/_emacs"))
(setq init-file "~/_emacs")))
(save-excursion
(set-buffer (find-file-noselect
(substitute-in-file-name init-file)))
(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 "\n(put '" (symbol-name command) " 'disabled t)\n")
(save-buffer))))
(provide 'novice)