puts Time.now

def urlescape(string)
  string.gsub(/([^ a-zA-Z0-9_.-]+)/n) do
    '%' + $1.unpack('H2' * $1.size).join('%').upcase
  end.tr(' ', '+')
end

require 'net/http'

numthreads = 10

input = File.new('input.txt', 'r')
output = File.new('output.txt', 'w')
threads = Array.new

1.upto(numthreads) do |w|
  threads << Thread.new(w) do |w|
    while line = input.gets
      next if line =~ /^#/

      yurl = "/export?p=#{urlescape(line.chomp)}&bwm=i&fr=sfp"

      line = Net::HTTP.get('siteexplorer.search.yahoo.com', yurl)

      line.scan(/\t(.+?)\t/) do |url|
	output.write(url[0]+"\n") unless url[0].index('http').nil?
      end
    end
  end
end

threads.each do |t| t.join end

input.close
output.close

puts Time.now