According to the documentation:
Triggerhappy is a hotkey daemon developed with small and embedded systems in
mind, e.g. linux based routers. It attaches to the input device files and
interprets the event data received and executes scripts configured in its
configuration.
Keyboard volume control is one of the areas where it proves useful, according to this post.
Based on that, it probably won't be of much use in the remote headless scenario for most people, but given its versatility it can be used in many other interesting situations. One such example is shutting down a headless Raspberry Pi with a mouse button. See this post on hackernoon for details on how to do that.
If you often find yourself ssh'ing onto your Pi (or connecting a keyboard and display) to launch some simple command (like shutdown), thd
might be for you.
sudo apt-get remove triggerhappy
– Ralph Bolton Dec 06 '19 at 08:53