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(elisp)Disabling Commands

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Disabling Commands
==================

   "Disabling a command" marks the command as requiring user
confirmation before it can be executed.  Disabling is used for commands
which might be confusing to beginning users, to prevent them from using
the commands by accident.

   The low-level mechanism for disabling a command is to put a
non-`nil' `disabled' property on the Lisp symbol for the command.
These properties are normally set up by the user's init file (Note:
Init File) with Lisp expressions such as this:

     (put 'upcase-region 'disabled t)

For a few commands, these properties are present by default (you can
remove them in your init file if you wish).

   If the value of the `disabled' property is a string, the message
saying the command is disabled includes that string.  For example:

     (put 'delete-region 'disabled
          "Text deleted this way cannot be yanked back!\n")

   Note: Disabling, for the details on what happens
when a disabled command is invoked interactively.  Disabling a command
has no effect on calling it as a function from Lisp programs.

 - Command: enable-command command
     Allow COMMAND to be executed without special confirmation from now
     on, and (if the user confirms) alter the user's init file (Note:
     Init File) so that this will apply to future sessions.

 - Command: disable-command command
     Require special confirmation to execute COMMAND from now on, and
     (if the user confirms) alter the user's init file so that this
     will apply to future sessions.

 - Variable: disabled-command-hook
     When the user invokes a disabled command interactively, this
     normal hook is run instead of the disabled command.  The hook
     functions can use `this-command-keys' to determine what the user
     typed to run the command, and thus find the command itself.  Note:
     Hooks.

     By default, `disabled-command-hook' contains a function that asks
     the user whether to proceed.