aria2 downloader

xcode.rb

require 'rubygems'
require 'mechanize'

if ARGV.size < 3
  puts %q{Usage: ruby xcode.rb USERNAME PASSWORD "DOWNLOAD_URL" [WGET_PARAMS]}
  puts %q{Example: ruby xcode.rb myusername@apple.com 123456  "https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_4_and_ios_sdk_4.3__final/xcode_4_and_ios_sdk_4.3__final.dmg"  }
  exit
end

a = Mechanize.new { |agent|
  agent.user_agent_alias = 'Mac Safari'
}

a.get('https://developer.apple.com/') do |page|
  member_page = a.click(page.link_with(:text => /Member Center/))
  login = member_page.form_with(:name => 'appleConnectForm') do |form|
    form.theAccountName  = ARGV[0]
    form.theAccountPW = ARGV[1]
  end.submit

  a.redirect_ok = false
  download_page = a.get(ARGV[2])  
  system %Q{ aria2c -c -s10 -x10 #{download_page.response["location"]} --header "Cookie: #{download_page.response["set-cookie"]}" #{ARGV[3]}}
end

Tried @kukat 's Cookie Export one, it worked.