sound_sink_switcher.sh

#!/bin/bash

# get list of sinks/cards (for settings CARD1/CARD2)
# For each of your audio interfaces, run:
# pactl get-default-sink

CARD1="alsa_output.pci-0000_0a_00.1.hdmi-stereo-extra1" # Speakers
CARD2="alsa_output.usb-Focusrite_Scarlett_2i4_USB-00.HiFi__Line1__sink" # Headphones

CURRENT_SINK=$(pactl get-default-sink)

function setCard() {

  if [ "$CURRENT_SINK" == "$1" ]
   then
     echo "Already using this Sink"
     exit 1
  fi

  SINK=$(pactl set-default-sink "$1")

  echo "Setting default sink to: $1";

  notify-send --urgency=low "Audio Switching" "SINK: $1"
}

function toggleSinks() {
  if [ "$CURRENT_SINK" == "$CARD1" ]
    then
      setCard $CARD2
    else
      setCard $CARD1
    fi
}


function showHelp() {
  echo "------------------------------------"
  echo "AUDIO SINK SWITCHER"
  echo " "
  echo "$0 [options]"
  echo " "
  echo "options:"
  echo "-h  --help        What you are looking at.."
  echo "-p, --headphones  Sets Headphones as output device"
  echo "-s, --speakers    Sets Speakers as output device"
  echo "-t, --toggle      Toggles the different output devices"
  echo " "
  echo "------------------------------------"
}

# check args length
if [ $# -eq 0 ]
  then
    echo "Toggling output devices (Speakers/Headset)"
    toggleSinks
fi


# arg options
while test $# -gt 0; do
  case "$1" in
    -h|--help)
        showHelp
        exit 1
        ;;
    -s|--headphones)
        setCard $CARD2
        exit 1
        ;;
    -s|--speakers)
        setCard $CARD1
        exit 1
        ;;
    -t|--toggle)
        toggleSinks
        echo "Toggling output devices (Speakers/Headset)"
        exit 1
        ;;
     *)
        showHelp
        exit 1
        ;;
  esac
done