OS=$(uname -s)
REL=$(uname -r)

function sorry()
{
    echo "Sorry. I do not know how to flush the DNS on this OS."
    echo "Once you find out, edit $(readlink ${0})."
    exit 1
}

case ${OS} in
    Darwin) case ${REL} in
                14.*) sudo discoveryutil udnsflushcaches
                        ;;
                     *) sorry
                        ;;
            esac
            ;;

         *) sorry
            ;;
esac

exit 0