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Switch Audio Outputs with a Hotkey

Create a shell script to switch audio output devices on Linux systems.

Posted: September 11, 2020 Updated:
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This script will cycle to the next available audio output device. It can be tied to a hotkey to easily be triggered. This is handy, for example, for swapping between speakers and headphones.

This script will work on systems running PulseAudio or Pipewire services.

Tools/commands used in this script

  • declare - declares a new variable, allows for setting ‘types’
  • pacmd - provides information about PulseAudio audio devices
  • pactl - provides information about PipeWire audio devices
  • notify-send - sends pop-up notifications to user (may need to be installed with sudo apt install libnotify-bin)
    • Icons -i can be found in the following locations:
      • /usr/share/icons/gnome/32x32
      • /usr/share/notify-osd/icons/
  • grep - the ever useful search command
  • sed - the inline editing tool
  • mapfile - the recommended way to populate arrays from grep results
  • Run through ShellCheck to verify script.

Complete Script

#!/bin/bash

# Check which sound server is running
if pgrep pulseaudio >/dev/null; then
  sound_server="pulseaudio"
elif pgrep pipewire >/dev/null; then
  sound_server="pipewire"
else
  echo "Neither PulseAudio nor PipeWire is running."
  exit 1
fi

# Grab a count of how many audio sinks we have
if [[ "$sound_server" == "pulseaudio" ]]; then
  sink_count=$(pacmd list-sinks | grep -c "index:[[:space:]][[:digit:]]")
  # Create an array of the actual sink IDs
  sinks=()
  mapfile -t sinks < <(pacmd list-sinks | grep 'index:[[:space:]][[:digit:]]' | sed -n -e 's/.*index:[[:space:]]\([[:digit:]]\)/\1/p')
  # Get the ID of the active sink
  active_sink=$(pacmd list-sinks | sed -n -e 's/[[:space:]]*\*[[:space:]]index:[[:space:]]\([[:digit:]]\)/\1/p')

elif [[ "$sound_server" == "pipewire" ]]; then
  sink_count=$(pactl list sinks | grep -c "Sink #[[:digit:]]")
  # Create an array of the actual sink IDs
  sinks=()
  mapfile -t sinks < <(pactl list sinks | grep 'Sink #[[:digit:]]' | sed -n -e 's/.*Sink #\([[:digit:]]\)/\1/p')
  # Get the ID of the active sink
  active_sink_name=$(pactl info | grep 'Default Sink:' | sed -n -e 's/.*Default Sink:[[:space:]]\+\(.*\)/\1/p')
  active_sink=$(pactl list sinks | grep -B 2 "$active_sink_name" | sed -n -e 's/Sink #\([[:digit:]]\)/\1/p' | head -n 1)
fi

# Get the ID of the last sink in the array
final_sink=${sinks[$((sink_count - 1))]}

# Find the index of the active sink
for index in "${!sinks[@]}"; do
  if [[ "${sinks[$index]}" == "$active_sink" ]]; then
    active_sink_index=$index
  fi
done

# Default to the first sink in the list
next_sink=${sinks[0]}
next_sink_index=0

# If we're not at the end of the list, move up the list
if [[ $active_sink -ne $final_sink ]]; then
  next_sink_index=$((active_sink_index + 1))
  next_sink=${sinks[$next_sink_index]}
fi

#change the default sink
if [[ "$sound_server" == "pulseaudio" ]]; then
  pacmd "set-default-sink ${next_sink}"
elif [[ "$sound_server" == "pipewire" ]]; then
  # Get the name of the next sink
  next_sink_name=$(pactl list sinks | grep -C 2 "Sink #$next_sink" | sed -n -e 's/.*Name:[[:space:]]\+\(.*\)/\1/p' | head -n 1)
  pactl set-default-sink "$next_sink_name"
fi

#move all inputs to the new sink
if [[ "$sound_server" == "pulseaudio" ]]; then
  for app in $(pacmd list-sink-inputs | sed -n -e 's/index:[[:space:]]\([[:digit:]]\)/\1/p'); do
    pacmd "move-sink-input $app $next_sink"
  done
elif [[ "$sound_server" == "pipewire" ]]; then
  for app in $(pactl list sink-inputs | sed -n -e 's/.*Sink Input #\([[:digit:]]\)/\1/p'); do
    pactl "move-sink-input $app $next_sink"
  done
fi

# Create a list of the sink descriptions
sink_descriptions=()
if [[ "$sound_server" == "pulseaudio" ]]; then
  mapfile -t sink_descriptions < <(pacmd list-sinks | sed -n -e 's/.*alsa.name[[:space:]]=[[:space:]]"\(.*\)"/\1/p')
elif [[ "$sound_server" == "pipewire" ]]; then
  mapfile -t sink_descriptions < <(pactl list sinks | sed -n -e 's/.*Description:[[:space:]]\+\(.*\)/\1/p')
fi

# Find the index that matches our new active sink
for sink_index in "${!sink_descriptions[@]}"; do
  if [[ "$sink_index" == "$next_sink_index" ]]; then
    notify-send -i audio-volume-high "Sound output switched to ${sink_descriptions[$sink_index]}"
    exit
  fi
done

Install

  1. Create the file audio-device-switch.sh, paste in the script, and place it in /usr/local/bin.
  2. Make the script executable: sudo chmod 755 /usr/local/bin/audio-device-switch.sh.
  3. Open the Keyboard Shortcuts settings page, add a new shortcut, tell it to execute audio-device-switch.sh, and set up your shortcut!
  4. Install the notify-send library if you want to see a popup notification when the audio device switches: sudo apt install libnotify-bin.

Customizations

Feel free to modify this script and make it your own. Some ideas for customization:

Different icon in the notification

Line 83 of the script calls notify-send with the -i flag which defines which icon is displayed. Stock icons are found in:

  • /usr/share/icons/gnome/32x32
  • /usr/share/notify-osd/icons/

Acknowledgements

This is a more modern, robust rewrite of tsvetan’s solution on the Ubuntu forums.