Difference between revisions of "Keyboard macros"

Revision as of 22:13, 23 March 2014

Basic Keyboard Macro (`(info "(emacs) Basic Keyboard Macro")')

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

Basic Use

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

Example usage

Consider the standard *scratch* buffer:

;; 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.

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 C-x ( to start recording your macro. Note: If you hit C-g or if an error occurs, your keyboard macro recording will stop.
Hit C-s followed by a 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.

Hit C-e C-f to move point to the beginning of the next line.
Hit C-x ) to finish the recording of our macro.

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.

Hit C-x e once to call that macro.
Continue hitting e to call it several times. Hit any other key to get out of the macro repetition.

Saving macros

Save Keyboard Macro (`(info "(emacs) Save Keyboard Macro")')

Binding to a key

To bind a keyboard macro to a key use C-x C-k b. To avoid problems caused by overriding existing bindings, the key sequences C-x C-k 0 through C-x C-k 9 and C-x C-k A through C-x C-k Z 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:

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

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

line number 1
line number 2
line number 3
line number 4

@@ Line 2: / Line 2: @@
 '''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==
@@ Line 32: / Line 46: @@
 <li>Continue hitting <code>e</code> to call it several times. Hit any other key to get out of the macro repetition.</li>
 </ol>
-I think the exposure looks relaly good with the flash!  I am having the hardest time figuring out what is the "right" exposure using my speedlight also.  I think this looks great and u got great catchlights, no pinlights.  Very sweet post.  :)
 ==Saving macros==
 {{Manual|emacs|Save-Keyboard-Macro|Save Keyboard Macro}}
-===By name===
-To give a macro a name which you can later call using <code>M-x</code>, hit <code>C-x C-k n</code>.  Try to avoid strange characters in the name.  Once you've given it a name, you can execute it using <code>M-x the-name-of-the-macro</code>.
 ===Binding to a key===
-To bind a keyboard macro to a key using <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.
+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.
-===Saving it permanently===
+==Variables==
-To save a keyboard macro for future Emacs sessions, go to your init file (or wherever you want to store it) and hit <code>M-x insert-kbd-macro</code>.  Then enter the name of the macro you would like to save.  This will insert Emacs Lisp code which defines the macro you chose, so you can use it in future sessions.
-Using the example in the beginning of this article, let's say you named that macro <code>remove-first-a</code>.  If you use <code>insert-kbd-macro</code> to insert the Lisp for that macro, this is what would come up:
+Variables can be stored in lisp or in [[registers]].  Here's an example using lisp:
 <pre>
-(fset 'remove-first-a
+[M-: (setq x 1)]
-   (lambda (&optional arg) "Keyboard macro." (interactive "p") (kmacro-exec-ring-item (quote ([19 97 13 backspace 5 6] 0 "%d")) arg)))
+<F3>
+Line number [C-u M-: x]
+[M-: (setq x (+ x 1))]
+<F4>
 </pre>
-If you have bound the macro to a key as described in the previous section, you can generate the code for that as well by prefixing the insert-kbd-macro call with [[prefix argument|<code>C-u</code>]].
+Now execute the macro four times with the command <code>C-x e e e e</code> and you get:
-[[Category:Intermediate]]
+line number 1<br />
-[[Category:Editing]]
+line number 2<br />
+line number 3<br />
+line number 4