Find Latest Versions of Ruby 2.2, 2.3 and 2.4

latest_ruby.rb

#!/usr/bin/env ruby

# frozen_string_literal: true

require 'net/ftp'

module LatestRubies
  HOST = 'ftp.ruby-lang.org'
  DIR = 'pub/ruby'

  def self.call versions = [2.2, 2.3, 2.4]
    ftp = Net::FTP.new HOST

    ftp.login

    urls = versions.map do |version|
      "ftp://#{HOST}/#{ftp.nlst("#{DIR}/#{version}/ruby-#{version}.*.tar.gz").max}"
    end

    ftp.close

    urls
  end
end

puts LatestRubies.call