Macros allow you to send multiple keystrokes when pressing just one key. QMK has a number of ways to define and use macros. These can do anything you want: type common phrases for you, copypasta, repetitive game movements, or even help you code.
!> **Security Note**: While it is possible to use macros to send passwords, credit card numbers, and other sensitive information it is a supremely bad idea to do so. Anyone who gets a hold of your keyboard will be able to access that information by opening a text editor.
Sometimes you want a key to type out words or phrases. For the most common situations, we've provided `SEND_STRING()`, which will type out a string (i.e. a sequence of characters) for you. All ASCII characters that are easily translatable to a keycode are supported (e.g. `qmk 123\n\t`).
We first define a new custom keycode in the range not occupied by any other keycodes.
Then we use the `process_record_user` function, which is called whenever a key is pressed or released, to check if our custom keycode has been activated.
If yes, we send the string `"QMK is the best thing ever!"` to the computer via the `SEND_STRING` macro (this is a C preprocessor macro, not to be confused with QMK macros).
We return `true` to indicate to the caller that the key press we just processed should continue to be processed as normal (as we didn't replace or alter the functionality).
In addition to the `process_record_user()` function, is the `post_process_record_user()` function. This runs after `process_record` and can be used to do things after a keystroke has been sent. This is useful if you want to have a key pressed before and released after a normal key, for instance.
In this example, we modify most normal keypresses so that `F22` is pressed before the keystroke is normally sent, and release it __only after__ it's been released.
By default, it assumes a US keymap with a QWERTY layout; if you want to change that (e.g. if your OS uses software Colemak), include this somewhere in your keymap:
If for some reason you're manipulating strings and need to print out something you just generated (instead of being a literal, constant string), you can use `send_string()`, like this:
There are some functions you may find useful in macro-writing. Keep in mind that while you can write some fairly advanced code within a macro, if your functionality gets too complex you may want to define a custom keycode instead. Macros are meant to be simple.
?> You can also use the functions described in [Useful function](ref_functions.md) and [Checking modifier state](feature_advanced_keycodes#checking-modifier-state) for additional functionality. For example, `reset_keyboard()` allows you to reset the keyboard as part of a macro and `get_mods() & MOD_MASK_SHIFT` lets you check for the existence of active shift modifiers.
This is a boolean value that can be tested to see if the switch is being pressed or released. An example of this is
```c
if (record->event.pressed) {
// on keydown
} else {
// on keyup
}
```
### `register_code(<kc>);`
This sends the `<kc>` keydown event to the computer. Some examples would be `KC_ESC`, `KC_C`, `KC_4`, and even modifiers such as `KC_LSFT` and `KC_LGUI`.
### `unregister_code(<kc>);`
Parallel to `register_code` function, this sends the `<kc>` keyup event to the computer. If you don't use this, the key will be held down until it's sent.
Sends `register_code(<kc>)` and then `unregister_code(<kc>)`. This is useful if you want to send both the press and release events ("tap" the key, rather than hold it).
If `TAP_CODE_DELAY` is defined (default 0), this function waits that many milliseconds before calling `unregister_code(<kc>)`. This can be useful when you are having issues with taps (un)registering.
If the keycode is `KC_CAPS`, it waits `TAP_HOLD_CAPS_DELAY` milliseconds instead (default 80), as macOS prevents accidental Caps Lock activation by waiting for the key to be held for a certain amount of time.
### `tap_code_delay(<kc>, <delay>);`
Like `tap_code(<kc>)`, but with a `delay` parameter for specifying arbitrary intervals before sending the unregister event.
### `register_code16(<kc>);`, `unregister_code16(<kc>);` and `tap_code16(<kc>);`
These functions work similar to their regular counterparts, but allow you to use modded keycodes (with Shift, Alt, Control, and/or GUI applied to them).
Eg, you could use `register_code16(S(KC_5));` instead of registering the mod, then registering the keycode.
### `clear_keyboard();`
This will clear all mods and keys currently pressed.
### `clear_mods();`
This will clear all mods currently pressed.
### `clear_keyboard_but_mods();`
This will clear all keys besides the mods currently pressed.
This macro will register `KC_LALT` and tap `KC_TAB`, then wait for 1000ms. If the key is tapped again, it will send another `KC_TAB`; if there is no tap, `KC_LALT` will be unregistered, thus allowing you to cycle through windows.