Add sound to waybar on linux.

ansible/roles/sway/files/waybar_sound_linux.bash

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+#
+# Read volume status in FreeBSD
+set -euo pipefail
+IFS=$'\n\t'
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+SLEEP_INTERVAL=${SLEEP_INTERVAL:-30}
+
+while true; do
+    current_vol_decimal=$(wpctl get-volume @DEFAULT_AUDIO_SINK@ | sed 's/Volume: //g')
+    current_vol_percent=$(bc -s <<<"$current_vol_decimal * 100")
+    current_vol_percent=${current_vol_percent%.*} # Remove decimal
+    tooltip="<tt>$(wpctl status)</tt>"
+    tooltip=${tooltip//$'\n'/\\n}
+    tooltip=${tooltip//$'\t'/\\t}
+    class=""
+    icon=""
+
+    if [ $current_vol_percent -eq 0 ]; then
+        icon="🔇"
+    elif [ $current_vol_percent -le 50 ]; then
+        icon="🔉"
+    else
+        icon="🔊"
+    fi
+
+    jq --unbuffered --compact-output <<EOF
+{
+"text":"${current_vol_percent}% ${icon}",
+"tooltip":"${tooltip}",
+"percentage":${current_vol_percent},
+"class":"${class}"
+}
+EOF
+    sleep $SLEEP_INTERVAL
+done