ニコニコ動画サムネイルダウンローダ

nico_parser.rb

# thanks to http://swiftfox.blog6.fc2.com/blog-entry-301.html

require 'net/http'
require 'uri'
require 'nokogiri'
require 'open-uri'

def get_parser(url)
  uri = URI.parse(url)
  html = Net::HTTP.get(uri)
  Nokogiri::HTML.parse(html)
end

parser = get_parser('http://swiftfox.blog6.fc2.com/blog-entry-301.html')
thumb_urls = parser
  .xpath('//iframe')
  .map { |iframe| iframe.attribute('src').value }
  .select { |iframe_url| iframe_url.match %r(http://ext.nicovideo.jp/thumb/sm\d+) }
thumb_urls.each do |thumb_url|
  thumb_parser = get_parser(thumb_url)
  thumb_img_src = thumb_parser.xpath('//img[@class="video_img"]').attribute('src').value
  $stderr.puts "Downloading #{thumb_img_src}..."
  open(thumb_img_src) do |image|
    file_id = thumb_img_src.scan(/\d+$/)[0]
    File.open("images/smile_#{file_id}.jpg", 'wb') do |file|
      file.puts(image.read)
    end
  end
end