#!/bin/bash

URL="ftp://ftp.isc.org/isc/bind9/"

# Get version number from FTP server
VERSION=$(curl -s --list-only "$URL" | grep -E '^[0-9]{1,}\.[0-9]{1,}(\.[0-9]{1,})?$' | cut -d '-' -f2 | sort -V | tail -n1)

echo "$VERSION"