Utility to extract ports from nmap grepable output

nmapPorts.sh

#!/bin/bash

# To be used with nmap grepable output (-oG option)
if [ -z $1 ]; then
        echo "Usage: $(basename $0) <grepable-nmap-input-file>"
        exit -1
fi

ports="`cat $1 | grep -oP '\s\K[0-9]+(?=/)'`"
echo $ports | xargs | sed 's/ /,/g'