I want to write to a file when a modifier key is released on linux so I can run a custom handler in Emacs.
I've found that xbindkeys can run commands key release events when regular keys are pressed and when a modifier and a regular key is pressed. However it does nothing when a modifier alone is released.
I want something that I can run as a command line tool in the background.
The closest I have found is the python keyboard package but it needs root.
I did some more searching and found https://pypi.org/project/pynput/. It's like python keyboard but does not require root. I can use that to build a command line app but I wish there was one that existed already.