unused port range finder

unused_range.sh

#!/usr/bin/env bash

starting_port=$1
ending_port=$2

free_range=true
function check_range {
        echo "Checking if range is free..."
        for i in $(seq $starting_port $ending_port); do
		echo "Checking port $i"
                if lsof -Pi :$i -sTCP:LISTEN -t >/dev/null; then
                        echo "$i is in use, port range not free"
                        free_range=false
                fi
        done
        if $free_range; then
          echo "Port range is free."
        fi
}

check_range