1 files changed, 112 insertions, 0 deletions
diff --git a/bin/volume b/bin/volume
new file mode 100755
index 0000000..991fbc7
--- /dev/null
+++ b/bin/volume
@@ -0,0 +1,112 @@
+#!/bin/sh
+set -eu
+
+usage() {
+	cat <<-'EOF'
+		Usage:
+		  volume ACTION
+		  volume -h
+	EOF
+}
+
+help() {
+	cat <<-'EOF'
+
+		Options:
+		  -h, --help    show this message
+
+		  ACTION        one of:
+		                - up
+		                - down
+		                - toggle
+		                - rotate
+
+
+		Manage the audio output.
+
+
+		Examples:
+
+		  Increase the volume:
+
+		    $ volume up
+
+
+		  Toggle mute/unmute in the current audio output:
+
+		    $ volume toggle
+
+
+		  Change the audio output:
+
+		    $ volume rotate
+	EOF
+}
+
+for flag in "$@"; do
+	case "$flag" in
+		--)
+			break
+			;;
+		--help)
+			usage
+			help
+			exit
+			;;
+		*)
+			;;
+	esac
+done
+
+while getopts 'h' flag; do
+	case "$flag" in
+		h)
+			usage
+			help
+			exit
+			;;
+		*)
+			usage >&2
+			exit 2
+			;;
+	esac
+done
+shift $((OPTIND - 1))
+ACTION="${1:-}"
+
+eval "$(assert-arg "$ACTION" 'ACTION')"
+
+
+rotate() {
+	# This script assumes that at most 2 sinks exist at any time.
+	# When this premise is no longer true, it needs to be upgraded.
+
+	CURRENT="$(pacmd list-sinks | grep '\* index' | cut -d: -f2 | tr -d ' ')"
+	OTHER="$(pacmd list-sinks | grep index | grep -v '\* index' | tail -n1 | cut -d: -f2 | tr -d ' ')"
+
+	if [ "$CURRENT" = 0 ]; then
+		pacmd set-default-sink "$OTHER"
+	else
+		pacmd set-default-sink 0
+	fi
+}
+
+case "$ACTION" in
+	up)
+		pactl set-sink-volume @DEFAULT_SINK@ +10%
+		;;
+	down)
+		pactl set-sink-volume @DEFAULT_SINK@ -10%
+		;;
+	toggle)
+		pactl set-sink-mute @DEFAULT_SINK@ toggle
+		;;
+	rotate)
+		rotate
+		;;
+	*)
+		printf 'Bad ACTION: %s.\n\n' "$ACTION" >&2
+		usage >&2
+		exit 2
+		;;
+esac