#!/bin/bash

curl "ftp://ftp.gnu.org/gnu/libunistring/" 2> /dev/null | \
  awk '{print $9}' | \
  grep "^libunistring-[0-9.-]*\.tar\.[xg]z\$" | \
  sed "s|^libunistring-\([0-9.-]*\)\.tar\.[xg]z\$|\1|" | \
  sort -V | \
  tail -n1