midi-udev

Run commands when a midi device connects on linux (alsa).

This is unreviewed AI-generated code.

Motivation

I wanted use fluid-synth with an autio

Alternatives and prior work

udev-cli (also mine) reacts to udev events. Here we need to wait until alsa has detected the device before connecting it. You could use a udev rules, but I have had difficulty debugging these.

It would be fairly simple to code this useful, either by connecting to udev (with some retry logic for races) or with with an alsa client.

aseqdump -p 0:1 prints the raw ALSA announce events this is built on.

Apparently, amidiminder keeps ALSA connections according to rules. Good if all you want is connections, but it doesn't run commands.

Related tools

I wrote a tool called midi-exec which responds to midi events such as key presses and runs commands.

Installation

pipx install midi-udev

Needs aseqdump and aconnect (alsa-utils).

Usage

To print all MIDI clients coming and going as JSONL use: midi-udev. For hardware devices only use midi-udev -k. Clients whose name contains "keystation", including ones already plugged in: midi-udev -e -n keystation

To run a comand (the event JSON is appended as the last argument) use midi-udev -e -k -n keystation --run ./piano-handl@Ier

Events look like:

{"action": "add", "client": 24, "name": "USB Keystation 88es", "type": "kernel", "pid": null, "ports": [{"port": 0, "name": "USB Keystation 88es MIDI 1", "address": "24:0"}]}

About

I am @readwith. I am making tools for reading and agency with and without AI. I also make a lot of small tools related to productivity. If this tool is useful you might like follow me on github or X.