Multithreaded Ruby Rogue Podcast Slurper

rr_sluper_multi.rb

#!/usr/bin/env ruby 

require 'nokogiri'
require 'open-uri'

MAX_THREADS = 5
thread_pool = []

index = Nokogiri::HTML(open('http://rubyrogues.com/episode-guide/'));

index.css('a[rel=bookmark]').each do |link|
  while thread_pool.size >= MAX_THREADS
    Thread.list.each do |t|
      thread_pool.delete!(t) unless t.alive?
      sleep(1)
    end
  end

  t = Thread.new do
    podcast = Nokogiri::HTML(open(link['href']));
    title = podcast.css('.entry-title').text
    clean_title = title.gsub(/[^a-zA-Z0-9]/, '-') + '.mp3'
    clean_title.gsub!(/-{2,}/, '-')
    download_link = podcast.css('a[title=Download]')
    %x[wget -q -O '#{clean_title}' '#{download_link[0]['href']}']
  end

  thread_pool.push(t)
end