Listen to bluetooth headphone keys (Linux only)

What

Take action when you use your bluetooth headphone to indicate pause, play, next or previous. For Linux only.

Why

You can bind global keys to XF86AudioPause, XF86AudioPlay, XF86AudioNext, XF86AudioPrev, but does it work if you lock your screen? Probably not.

You can listen to ACPI event with acpid, but then you'll need to forward events from a system service to your user session.

Or you can read the events in your session (e.g. as a user service) with this program.

Setup

To give yourself permissions to read from the input device, put this in /etc/udev/rules.d/66-headphones.rules (the number in the filename should be lower than 70):

## give the user permissions to receive bluetooth headphone keys
SUBSYSTEM=="input", ATTRS{name}=="WH-1000XM2 (AVRCP)", TAG+="uaccess"

Where WH-1000XM2 (AVRCP) is the device name of your bluetooth headphone. Find out with the xinput or evtest program.

And then reload the rules:

sudo udevadm control --reload-rules
sudo udevadm trigger # or reconnect your headphone

Configure

See config.toml and update as you like. The values of commands are run by the system shell (/bin/sh).

Run

You need to run this program in your session (i.e. no sudo, no su).

cargo run --release config.toml

Or you can copy the built executable where you like and run that.