#!/bin/bash

URL="ftp://ftp.gnu.org/gnu/xorriso/"

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

# Remove '.tar.gz' suffix from VERSION variable
VERSION=${VERSION//.tar.gz/}

# Readd 'pl'
if [ $(echo "$VERSION" | tr -dc '.' | wc -c) -eq 3 ]; then
  VERSION=${VERSION%.*}.pl${VERSION##*.}
fi

echo "$VERSION"