#! /bin/bash

WAV="$1"
if [ -z "$WAV" ]; then
    echo "Usage: $0 OUTPUT.WAV" >&2
    exit 1
fi
rm -f "$WAV"

MONITOR=$(pactl list | grep -A2 '^Source #' | \
    grep 'Name: .*\.monitor$' | awk '{print $NF}' | tail -n1)
parec -d "$MONITOR" | sox -t raw -r 44100 -Lb 16 -e signed-integer -c 2 - "$WAV"