evdev-forward: toggle your keyboard and mouse between your desktop and a second X server (Linux)

Originally I wrote this for myself to multibox World of Warcraft, that I have since generalized for other purposes. I wanted to run a second client in its own X server and drive it with my real keyboard and mouse, and I couldn't find anything that did that cleanly.

It grabs your keyboard and mouse, and a hotkey (Ctrl+Shift+Space) switches them between your desktop and a target. The target can be another X server, like a second game client or a nested Xephyr window. Or it can be a set of virtual input devices that you assign to another seat, pass into a container, or hand to anything else that reads evdev.

It's a single small binary with no daemon and no config file. It finds your keyboard and mouse automatically, and you can point it at specific devices instead. Anything you're holding when you toggle gets released on both sides, so you don't end up with stuck keys. It doesn't need root, just the input group, and it builds with a plain ./configure && make. X support is optional.

If you need network forwarding or scriptable hotkeys, netevent and evsieve are more full-featured and worth a look. This one aims to be the option you can just run with no setup.

The repo and README cover setup, permissions, and how to try it in a Xephyr window: https://github.com/blakewon/evdev-forward

Feedback is welcome, drop a star if you find it useful.

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