gistfile1.rb

#!/usr/bin/ruby

require 'open-uri'
require 'base64'

url      = 'http://autoproxy-gfwlist.googlecode.com/svn/trunk/gfwlist.txt'
list_txt = Base64.decode64(open(url).read)
list     = list_txt.split("\n").reject do |item|
  item.start_with?('@@') ||
  item.start_with?('!')  ||
  item.start_with?('|')  ||
  item.start_with?('[')  ||
  item.empty?
end

script_list = list.collect do |item|
  %{shExpMatch(url, "*#{item}*")}
end

pac = %{function FindProxyForURL(url, host) {
  if (#{script_list.join(" ||\n      ")}
  ) {
    return "PROXY #{$*[0]}";
  } else {
    return "DIRECT";
  }
}}

File.open('gfwlist.pac', 'w') do |f|
  f << pac
end