das_download.rb

#!/usr/bin/env ruby
#
# requirements:
#   gem install mechanize
#
# usage:
#   das_download.rb [download_directory]

require 'mechanize'

path = ARGV[0] || './'

download = lambda do |url, file|
  agent = Mechanize.new
  agent.pluggable_parser.default = Mechanize::Download
  agent.get(url).save(file)
end

root = 'https://www.destroyallsoftware.com'

agent = Mechanize.new
agent.get("#{root}/screencasts/catalog")
screencasts = agent.page.search('div.episode').reverse
total = screencasts.size

resolution = '4k'
dwnld_slug = "download?resolution=#{resolution}"

index = 0
while screencast = screencasts.pop
  index += 1
  title = screencast.search('.title').first.text
  url   = "#{root}/#{screencast.search('a').first['href']}/#{dwnld_slug}"
  file  = "#{path}/#{'%03d' % index}_#{title.gsub(/\n\.|:|,/, '').gsub(/\/|\s+/, '-').downcase}.mp4"
  puts "Downloading\t#{title.ljust(32)}\tas\t#{file.ljust(48)}\t| #{index}/#{total}"
  next if File.exist?(file)
  download[url, file]
end