Ruby::Download railscasts(markdown format)

railscasts.rb

require 'rss'

url = 'http://feeds.feedburner.com/railscasts'
rss = RSS::Parser.parse(url)

rss.items.reverse.each do |item|
  puts "*  [#{item.title}](#{item.enclosure.url})"
end

railscasts_old.rb

require 'net/http'
require 'uri'

baseurl = "http://railscasts.com"
page = Net::HTTP.get URI.parse('http://railscasts.com/episodes/archive')
match = page.scan /<a href=\"\/episodes.*>/
puts "You have #{match.length} episodes"

File.open('railscasts.html','w') do |f|
  match.each do |data|
    f.puts data.sub!(/\/episodes/,'http://media.railscasts.com/videos')\
               .sub!(/\d+/) { |number| number.rjust(3, '0') }\
               .gsub!(/-/,'_')\
               .sub!(/\">/,'.mov">')\
               << '<br />'
  end
end