Utility to download torrent files from tokyotosho.info. It uses a similar heuristic to my own when looking for torrents, but could use some improvements.

tokyotosho.rb

#!/usr/bin/env ruby -w

require 'open-uri'
require 'uri'
require 'nokogiri'

DEFAULT_DIR = "/Users/carlosagarie/torrents"
CATEGORY = 1 # Anime.

# Regular expressions and constants for extraction.
RELEVANT_ENTRIES = "table.listing > tr.category_#{CATEGORY}"
MIME_TYPE = "application/x-bittorrent"
SIZE_RE = /Size:\s*([\d.]+)(?:K|M|G)B/
STATS_RE = /^S:\s*(\d+)\s*L:\s*(\d+).*/

# Class used to hold torrents.
Torrent = Struct.new(:name, :link, :size, :seeds, :leechers) do
  # Similar to the heuristics I use when looking for a torrent.
  def <=>(other)
    if self.seeds > 10 || other.seeds > 10
      other.seeds <=> self.seeds
    else
      other.leechers <=> self.leechers
    end
  end
  
  def to_s
    puts name
    puts "Size: #{size} | Seeds: #{seeds} | Leechers: #{leechers}"
    puts link
  end
end

def address(terms, type = CATEGORY)
  base_url = "http://tokyotosho.info/search.php?size_min=&size_max=&username="
  "#{base_url}&terms=#{terms.split(' ').join('+')}&type=#{type}"
end

url = address(ARGV[0])
page = Nokogiri::HTML(open(url))

# Get the torrent URLs from the main page. Yeah, tokyotosho.info HTML sucks.
results = []
page.css(RELEVANT_ENTRIES).each_slice(2) do |e|
  torrent = Torrent.new
  
  links = e[0].css('a').select { |l| l["type"] == MIME_TYPE }
  torrent.name = links[0].content
  torrent.link = links[0]["href"]
  
  torrent.size = e[1].css('td.desc-bot')[0].content.match(SIZE_RE)[1]
  
  e[1].css('td.stats')[0].content.match(STATS_RE) do |m|
    torrent.seeds = m[1].to_i
    torrent.leechers = m[2].to_i
  end
  
  results << torrent  
end

# Download the "best" torrent.
torrent = results.sort.shift
filename = File.join(DEFAULT_DIR, torrent.name + '.torrent')

File.open(filename, 'wb') do |f|
  f << open(torrent.link).read
end