17.1 Basic Use

Start defining a keyboard macro (kmacro-start-macro-or-insert-counter).
If a keyboard macro is being defined, end the definition; otherwise, execute the most recent keyboard macro (kmacro-end-or-call-macro).
C-u F3
Re-execute last keyboard macro, then append keys to its definition.
C-u C-u F3
Append keys to the last keyboard macro without re-executing it.
C-x C-k r
Run the last keyboard macro on each line that begins in the region (apply-macro-to-region-lines).
C-x (
Start defining a keyboard macro (old style) (kmacro-start-macro); with a prefix argument, append keys to the last macro.
C-x )
End a macro definition (old style) (kmacro-end-macro); prefix argument serves as the repeat count for executing the macro.
C-x e
Execute the most recently defined keyboard macro (kmacro-end-and-call-macro); prefix argument serves as repeat count.

To start defining a keyboard macro, type F3. From then on, your keys continue to be executed, but also become part of the definition of the macro. ‘Def’ appears in the mode line to remind you of what is going on. When you are finished, type F4 (kmacro-end-or-call-macro) to terminate the definition. For example,

F3 M-f foo F4

defines a macro to move forward a word and then insert ‘foo’. Note that F3 and F4 do not become part of the macro.

After defining the macro, you can call it with F4. For the above example, this has the same effect as typing M-f foo again. (Note the two roles of the F4 command: it ends the macro if you are in the process of defining one, or calls the last macro otherwise.) You can also supply F4 with a numeric prefix argument ‘n’, which means to invoke the macro ‘n’ times. An argument of zero repeats the macro indefinitely, until it gets an error or you type C-g (or, on MS-DOS, C-BREAK).

The above example demonstrates a handy trick that you can employ with keyboard macros: if you wish to repeat an operation at regularly spaced places in the text, include a motion command as part of the macro. In this case, repeating the macro inserts the string ‘foo’ after each successive word.

After terminating the definition of a keyboard macro, you can append more keystrokes to its definition by typing C-u F3. This is equivalent to plain F3 followed by retyping the whole definition so far. As a consequence, it re-executes the macro as previously defined. If you change the variable kmacro-execute-before-append to nil, the existing macro will not be re-executed before appending to it (the default is t). You can also add to the end of the definition of the last keyboard macro without re-executing it by typing C-u C-u F3.

When a command reads an argument with the minibuffer, your minibuffer input becomes part of the macro along with the command. So when you replay the macro, the command gets the same argument as when you entered the macro. For example,

F3 C-a C-k C-x b foo RET C-y C-x b RET F4

defines a macro that kills the current line, yanks it into the buffer ‘foo’, then returns to the original buffer.

Most keyboard commands work as usual in a keyboard macro definition, with some exceptions. Typing C-g (keyboard-quit) quits the keyboard macro definition. Typing C-M-c (exit-recursive-edit) can be unreliable: it works as you’d expect if exiting a recursive edit that started within the macro, but if it exits a recursive edit that started before you invoked the keyboard macro, it also necessarily exits the keyboard macro too. Mouse events are also unreliable, even though you can use them in a keyboard macro: when the macro replays the mouse event, it uses the original mouse position of that event, the position that the mouse had while you were defining the macro. The effect of this may be hard to predict.

The command C-x C-k r (apply-macro-to-region-lines) repeats the last defined keyboard macro on each line that begins in the region. It does this line by line, by moving point to the beginning of the line and then executing the macro.

In addition to the F3 and F4 commands described above, Emacs also supports an older set of key bindings for defining and executing keyboard macros. To begin a macro definition, type C-x ( (kmacro-start-macro); as with F3, a prefix argument appends this definition to the last keyboard macro. To end a macro definition, type C-x ) (kmacro-end-macro). To execute the most recent macro, type C-x e (kmacro-end-and-call-macro). If you enter C-x e while defining a macro, the macro is terminated and executed immediately. Immediately after typing C-x e, you can type e repeatedly to immediately repeat the macro one or more times. You can also give C-x e a repeat argument, just like F4 (when it is used to execute a macro).

C-x ) can be given a repeat count as an argument. This means to repeat the macro right after defining it. The macro definition itself counts as the first repetition, since it is executed as you define it, so C-u 4 C-x ) executes the macro immediately 3 additional times.