查IP的地址
require 'net/http'
require "uri"
def ip2addr(ip="google.com")
url=URI.parse("http://ip138.com/ips8.asp")
res=Net::HTTP.post_form(url,:ip=>ip,:action=>2)
res.body.scan(/<ul class="ul1">(.*)<\/ul>/).to_s.scan(/<li>(.*?)<\/li>/)
end
puts ip2addr
http://chinaonrails.com/topic/view/216.html