#!/bin/bash
# a function to run yoshimi on a certain "channel"
#     takes channel number as argument
function runyoshimi() {
    local CHAN=$1
    # store jack_lsp output before...
    local PRE=`jack_lsp`
    yoshimi &
    sleep 3
    # ... and after application startup
    local POST=`jack_lsp`
    # diff to find the new ports
    local PORTS=`diff <(echo "$PRE") <(echo "$POST")`
    # retrieve the actual port names from the resulting 3 lines
    LEFT=`echo "$PORTS" | grep left | cut -c 3-`
    RIGHT=`echo "$PORTS" | grep right | cut -c 3-`
    MIDI=`echo "$PORTS" | grep midi | cut -c 3-`
    # assign aliases
    jack_alias "$LEFT"  ch_${CHAN}_left
    jack_alias "$RIGHT" ch_${CHAN}_right
    jack_alias "$MIDI"  ch_${CHAN}_midi
}
# call the function
runyoshimi 4
# now use the new aliases
jack_connect                ch_4_left  system:playback_1
jack_connect               ch_4_right  system:playback_2
jack_connect Non-Sequencer:midi_out-4  ch_4_midi