EmacsWiki: Key Sequence (original) (raw)
A key, or more properly a key sequence, is similar to what is sometimes called a keyboard shortcut in other editors. However, in Emacs:
- A key sequence can be short for any command or keyboard macro; it is not necessarily short for a menu item.
- A key sequence is not necessarily a sequence of keyboard key presses. It can be any combination of the following:
- A sequence of keyboard key pressings and releases. Any element in such a sequence can be a chord composed of a non-modifier key and one or more modifier keys pressed at the same time.
- A sequence of mouse button or wheel actions. Any element in such a sequence can be a chord composed of a mouse-button pressing or mouse-wheel motion and one or more modifier keys pressed at the same time. In addition to pressing and releasing a mouse button, a button can be pressed and the mouse dragged before releasing. Such a drag operation can also be part of a key sequence.
- A sequence of menu choices, including from the MenuBar.
- A ToolBar icon choice.
- A key sequence can also include information on where you use a key or mouse button. Particular places include the ModeLine and the HeaderLine. It sometimes does this by including pseudokeys like `
[mode-line]’. Other places, like the MiniBuffer are just special buffers – see the explanation of buffer-local bindings, below.
A key sequence is typically bound to a command. This mapping or association is called a KeyBinding. For example, the command ‘forward-char’, meaning “move the TextCursor forward one character” is bound to the key sequence ‘C-f’. Even simple key sequences such as ‘s’ (just typing the letter “s”) are bound to commands in Emacs – ‘s’ is bound globally to the command ‘self-insert-command’, which just inserts an ‘s’ character.
Examples
The command ‘indent-code-rigidly’ is (by default) not bound to any keyboard sequence. The command ‘grep’ is (by default) not bound to a keyboard key sequence, but it is bound to the MenuBar key sequence Tools → Search Files (= [menu-bar tools grep]).
(You can invoke any Emacs command, whether or not it is bound to a key sequence, via ‘M-x’. Example: ‘M-x grep’ invokes the ‘grep’ command.)
A key sequence can be bound to different commands in different contexts. In particular, key sequences are sometimes buffer-local: specific to a given buffer. For example, although the global binding for key sequence ‘s’ is ‘self-insert-command’, in Dired mode ‘s’ is bound to the command ‘dired-sort-toggle-or-edit’, in Info mode ‘s’ is bound to ‘Info-search’, and in Buffer Menu mode ‘s’ is bound to ‘Buffer-menu-save’ (to pick just a few common modes).
You can tell which command, if any, a key sequence is bound to in any context by using ‘C-h k’ or ‘C-h c’. You can display short descriptions of all of the key sequences currently defined in any context by using ‘C-h b’.
Most importantly, in Emacs, YOU can bind any key sequence to any command, including commands that you create. This is a big part of what makes Emacs the most extensible editor.