Script to repeatedly check port availability on an endpoint. Takes server name and a port number as parameters.

port-percent.sh

#!/bin/bash
if [[ $# -ne 2 ]]; then
    echo "Please submit 2 arguments: server name and port number"
else
    total=0
    success=0
    while true; do
        total=$((total+1))
        result=$(nmap -Pn -p $2 $1 | grep "/tcp")
        echo -n $result
        open=$(echo $result | awk '{print $2}')
        if [[ $open == "open" ]]; then
            success=$((success+1))
        fi

        length=$(echo $result | wc -c)
        if [[ $total -eq 1 ]]; then
            baseline=$length
        elif [[ $length -lt $baseline ]]; then
            baseline=$length
        fi

        percent=$(echo "scale=2;100*$success/$total" | bc)
        if [[ $length -gt $baseline ]]; then
            echo -e " > \t$success / $total  -  $percent% "
        else
            echo -e " > \t\t$success / $total  -  $percent%"
        fi

        sleep 5
    done
fi