evmuxd - Man Page

Event Device Multiplexing Daemon


evmuxd device


This tool creates two Linux virtual keyboards and forwards the events from a given physical keyboard to either of the two. It's possible to switch the target of the redirect with a special key press.

This is useful when the user wants to assign a special purpose to one of the keyboard while grabbing it (such as exporting the keyboard via btkbdd(8)) while still retaining the local keyboard functionality on his system.

The virtual keyboard have a sysfs attribute name set to evmuxd primary and evmuxd secondary with the primary one being chosen by default.

The special key used is SCROLL LOCK.



Linux input subsystem event device to use as event source.


Use with udev(7) and systemd(1) is recommended. Look into 89-evmuxd.rules and evmuxd@.service files distributed with evmuxd for examples.


It's possible to create only two devices.

It's not possible to configure the magic key.

It's not possible to control the virtual keyboard metadata, such as name, product and vendor IDs or version.

Only keyboard input devices are supported.


evmuxd can be redistributed under the terms of GNU General Public License (any version at your option).

The source code repository can be obtained from <https://github.com/lkundrak/btkbdd>. Bug fixes and feature ehancements licensed under same conditions as evmuxd  are welcome via GIT pull requests.

See Also

btkbdd(7), systemd(1), systemd.service(5), systemd.unit(5).


2021-07-21 1.5 System management commands