Keyboard macros

2014-09-29T12:39:28Z

192.198.151.37: Undo revision 46809 by 120.43.4.33 (talk)

{{Manual|emacs|Basic-Keyboard-Macro|Basic Keyboard Macro}}

'''Keyboard macros''' can be used to automate or repeat tedious editing tasks in Emacs.

==Basic Use==

; {{Keys|F3}}, or {{Keys|C-x (}}
: Start defining a macro.
; {{Keys|F4}}, or {{Keys|C-x )}}
: Stop defining a macro.
; {{Keys|F4}}, or {{Keys|C-x e}}
: Execute a macro
; {{Keys|C-u 37 C-x e}} or {{Keys|C-u 37 F4}}
: Execute a macro multiple times, using [[prefix argument]]
; {{Keys|C-u 0 C-x e}}
: Execute a macro until the end of the buffer

==Example usage==

Consider the standard <code>*scratch*</code> buffer:

<pre>
;; This buffer is for notes you don't want to save, and for Lisp evaluation.
;; If you want to create a file, visit that file with C-x C-f,
;; then enter the text in that file's own buffer.
</pre>

Suppose you want to remove the first occurrence of the letter "a" on every row in that piece of text. You could write a [[regular expression]] to do the job, but let's assume you want to use a keyboard macro this time.

# Make sure [[point]] is at the start of the buffer.
# Hit <code>C-x (</code> to start recording your macro. '''Note:''' If you hit <code>C-g</code> or if an error occurs, your keyboard macro recording will stop.
# Hit <code>C-s</code> followed by <code>a</code> to find the first "a". Now, point is right after the first "a" in the text.
# Hit backspace to delete that "a".

The first occurrence of "a" of the first line has been deleted. Let's move point to the beginning of the next line and then stop recording.

<ol start="5">
<li>Hit <code>C-e C-f</code> to move point to the beginning of the next line.</li>
<li>Hit <code>C-x )</code> to finish the recording of our macro.</li>
</ol>

The macro you have just recorded performs the operation of removing the first occurrence of "a" it can find and then moving point to the next line.

<ol start="7">
<li>Hit <code>C-x e</code> once to call that macro.</li>
<li>Continue hitting <code>e</code> to call it several times. Hit any other key to get out of the macro repetition.</li>
</ol>

== Naming and saving macros ==

You can:
* give a name to the most recently defined macro (<code>C-x C-k n</code>)
* bind it to a key sequence (<code>C-x C-k b</code>)
* insert it in the current buffer as lisp code (<code>M-x insert-kbd-macro</code>).

{{Manual|emacs|Save-Keyboard-Macro|Save Keyboard Macro}}

To bind a keyboard macro to a key use <code>C-x C-k b</code>. To avoid problems caused by overriding existing bindings, the key sequences <code>C-x C-k 0</code> through <code>C-x C-k 9</code> and <code>C-x C-k A</code> through <code>C-x C-k Z</code> are reserved for your own keyboard macro bindings. You can, however, bind a keyboard macro to whatever you like.

==Variables==

Variables can be stored in lisp or in [[registers]]. Here's an example using lisp:

<pre>
[M-: (setq x 1)]
<F3>
Line number [C-u M-: x]
[M-: (setq x (+ x 1))]
<F4>
</pre>

Now execute the macro four times with the command <code>C-x e e e e</code> and you get:

line number 1<br />
line number 2<br />
line number 3<br />
line number 4

= See also =

* [https://github.com/Silex/elmacro elmacro], to show keyboard macros as emacs-lisp
* [https://github.com/abo-abo/centimacro centimacro] to (temporarily) bind any number of macros to any global shortcuts.
* You can use keyboard macros à la vim in [[evil]].

[[Category:Intermediate]]
[[Category:Editing]]

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Keyboard macros