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22.9 Controlling the Active Keymaps

— Variable: global-map

This variable contains the default global keymap that maps Emacs keyboard input to commands. The global keymap is normally this keymap. The default global keymap is a full keymap that binds self-insert-command to all of the printing characters.

It is normal practice to change the bindings in the global keymap, but you should not assign this variable any value other than the keymap it starts out with.

— Function: current-global-map

This function returns the current global keymap. This is the same as the value of global-map unless you change one or the other. The return value is a reference, not a copy; if you use define-key or other functions on it you will alter global bindings.

          (current-global-map)
          ⇒ (keymap [set-mark-command beginning-of-line ...
                      delete-backward-char])
— Function: current-local-map

This function returns the current buffer's local keymap, or nil if it has none. In the following example, the keymap for the *scratch* buffer (using Lisp Interaction mode) is a sparse keymap in which the entry for <ESC>, ASCII code 27, is another sparse keymap.

          (current-local-map)
          ⇒ (keymap
              (10 . eval-print-last-sexp)
              (9 . lisp-indent-line)
              (127 . backward-delete-char-untabify)
              (27 keymap
                  (24 . eval-defun)
                  (17 . indent-sexp)))

current-local-map returns a reference to the local keymap, not a copy of it; if you use define-key or other functions on it you will alter local bindings.

— Function: current-minor-mode-maps

This function returns a list of the keymaps of currently enabled minor modes.

— Function: use-global-map keymap

This function makes keymap the new current global keymap. It returns nil.

It is very unusual to change the global keymap.

— Function: use-local-map keymap

This function makes keymap the new local keymap of the current buffer. If keymap is nil, then the buffer has no local keymap. use-local-map returns nil. Most major mode commands use this function.

— Variable: minor-mode-map-alist

This variable is an alist describing keymaps that may or may not be active according to the values of certain variables. Its elements look like this:

          (variable . keymap)

The keymap keymap is active whenever variable has a non-nil value. Typically variable is the variable that enables or disables a minor mode. See Keymaps and Minor Modes.

Note that elements of minor-mode-map-alist do not have the same structure as elements of minor-mode-alist. The map must be the cdr of the element; a list with the map as the second element will not do. The cdr can be either a keymap (a list) or a symbol whose function definition is a keymap.

When more than one minor mode keymap is active, the earlier one in minor-mode-map-alist takes priority. But you should design minor modes so that they don't interfere with each other. If you do this properly, the order will not matter.

See Keymaps and Minor Modes, for more information about minor modes. See also minor-mode-key-binding (see Functions for Key Lookup).

— Variable: minor-mode-overriding-map-alist

This variable allows major modes to override the key bindings for particular minor modes. The elements of this alist look like the elements of minor-mode-map-alist: (variable . keymap).

If a variable appears as an element of minor-mode-overriding-map-alist, the map specified by that element totally replaces any map specified for the same variable in minor-mode-map-alist.

minor-mode-overriding-map-alist is automatically buffer-local in all buffers.

— Variable: overriding-local-map

If non-nil, this variable holds a keymap to use instead of the buffer's local keymap, any text property or overlay keymaps, and any minor mode keymaps. This keymap, if specified, overrides all other maps that would have been active, except for the current global map.

— Variable: overriding-terminal-local-map

If non-nil, this variable holds a keymap to use instead of overriding-local-map, the buffer's local keymap, text property or overlay keymaps, and all the minor mode keymaps.

This variable is always local to the current terminal and cannot be buffer-local. See Multiple Terminals. It is used to implement incremental search mode.

— Variable: overriding-local-map-menu-flag

If this variable is non-nil, the value of overriding-local-map or overriding-terminal-local-map can affect the display of the menu bar. The default value is nil, so those map variables have no effect on the menu bar.

Note that these two map variables do affect the execution of key sequences entered using the menu bar, even if they do not affect the menu bar display. So if a menu bar key sequence comes in, you should clear the variables before looking up and executing that key sequence. Modes that use the variables would typically do this anyway; normally they respond to events that they do not handle by “unreading” them and exiting.

— Variable: special-event-map

This variable holds a keymap for special events. If an event type has a binding in this keymap, then it is special, and the binding for the event is run directly by read-event. See Special Events.

— Variable: emulation-mode-map-alists

This variable holds a list of keymap alists to use for emulations modes. It is intended for modes or packages using multiple minor-mode keymaps. Each element is a keymap alist which has the same format and meaning as minor-mode-map-alist, or a symbol with a variable binding which is such an alist. The “active” keymaps in each alist are used before minor-mode-map-alist and minor-mode-overriding-map-alist.

— Function: set-temporary-overlay-map keymap &optional keep

This function adds keymap as a temporary keymap that takes precedence over most other keymaps. It does not take precedence over the “overriding” maps (see above); and unlike them, if no match for a key is found in keymap, the search continues.

Normally, keymap is used only once. If the optional argument pred is t, the map stays active if a key from keymap is used. pred can also be a function of no arguments: if it returns non-nil then keymap stays active.

For a pseudo-Lisp description of exactly how and when this keymap applies, see Searching Keymaps.