ruby设置user-agent

require 'net/http'
require 'uri'
require 'nokogiri'

uri = URI.parse('http://www.baidu.com')
http = Net::HTTP.new(uri.host, uri.port)
visit_url = "http://www.baidu.com/more/"
# 设置user-agent为ie7, windows vista
request = Net::HTTP::Get.new(visit_url, {'User-Agent' => 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; Trident/4.0)'})

response = http.request(request)
doc = Nokogiri::HTML(response.body)