waybar: added pipewire listener for displaying audio status changes in real time

.local/bin/waybar_audio_event_bridge.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+set -euo pipefail
+SIG=8
+
+get_waybar_pid() { pgrep -u "$USER" -x waybar | head -n1 || true; }
+log() { echo "[waybar-audio-bridge] $*" >&2; }
+
+WAYBAR_PID=""
+while [[ -z "$WAYBAR_PID" ]]; do
+  WAYBAR_PID="$(get_waybar_pid)"
+  sleep 1
+done
+log "connected to Waybar PID $WAYBAR_PID"
+
+# read pw-mon output, but only care about Audio nodes
+pw-mon 2>/dev/null | grep --line-buffered -E "Audio|Sink|Source|Stream|Node" | while read -r _; do
+  # small debounce to avoid spamming CPU when multiple updates arrive fast
+  sleep 0.2
+  if ! kill -0 "$WAYBAR_PID" 2>/dev/null; then
+    WAYBAR_PID="$(get_waybar_pid)"
+    [[ -z "$WAYBAR_PID" ]] && continue
+    log "reconnected to Waybar PID $WAYBAR_PID"
+  fi
+  kill -RTMIN+"$SIG" "$WAYBAR_PID" 2>/dev/null || true
+done
+