Attaches a midi device to Qsynth through ALSA

midi-to-qsynth

#!/usr/bin/env bash

# CONSTANTS
readonly MIDI_DEVICE_NAME=GarageKey

# VARIABLES
midi_device_port=
qsynth_port=

# FUNCTIONS
function get_qsynth_alsa_port() {
  if [[ -z "${qsynth_port}" ]]; then
    sleep 1
    qsynth_port=$(aconnect -l | grep -E "client.*Qsynth" | sed -E "s/client ([0-9]+).*/\1/g" -) 
  else 
    get_qsynth_alsa_port
  fi
}

echo "Fetching alsa port for ${MIDI_DEVICE_NAME}..."
midi_device_port=$(aconnect -l | grep -E "client.*${MIDI_DEVICE_NAME}" | sed -E "s/client ([0-9]+).*/\1/g" -)

echo "> Got port ${midi_device_port}. Using it as input"

echo "Launching Qsynth..."
qsynth -a alsa & &> /dev/null

echo "Fetching alsa port for Qsynth..."
get_qsynth_alsa_port

echo "> Got port ${qsynth_port}. Using it as output"

echo "Connecting device to Qsynth..."
aconnect ${midi_device_port} ${qsynth_port}

PS3="Play a note. Do you hear anything? How do you want to proceed?"
select answer in "Close" "Launch diagnosis tool" "Try again"; do
  case $REPLY in
    1)
      break
      ;;
    2)
      aseqdump -p ${midi_device_port}
      ;;
    3)
      $(basename $0) && exit
      ;;
    *) 
      echo "Invalid option $REPLY"
      ;;
  esac
done