regex-test.rb

#!/usr/bin/env ruby

require 'netaddr'

regexfile = ARGV[0]
testfile = ARGV[1]

regex = Regexp.new(File.read(regexfile)).freeze

File.foreach(testfile) do |test|
  if /-/ =~ test
    lower = NetAddr::CIDR.create(test.split('-').first.strip)
    upper = NetAddr::CIDR.create(test.split('-').last.strip)
    NetAddr.range(lower, upper).each do |ip|
      puts ip unless regex =~ ip
    end
  else
    NetAddr::CIDR.create(test.strip).enumerate.each do |ip|
      puts ip unless regex =~ ip
    end
  end
end