ruby实现修改ubuntu下的hosts

#!/usr/bin/ruby
#coding=utf-8
require 'open-uri'

url= "http ://raw.github usercontent.com/vokins/simpleu/master/hosts"

begin
 open("/etc/hosts","w") do |x|
  x.write open(url).read
 end
rescue Errno::EACCES
 puts "Need root"
 exec "sudo ruby " + $0 + ARGV.join(' ')
end
puts "Write hosts success!"