http_server.rb

#!/usr/bin/env ruby
require 'socket'

if $0 == __FILE__
  # write this
  gs = TCPServer.open("", 12345)
  socks= [gs]
  addr= gs.addr
  addr.shift
  
  printf("server is on %s\n", addr.join(":"))
  while true
    nsock= select(socks)
    next if nsock == nil
    nsock[0].each do |s|
      if s == gs
        socks.push(s.accept)
        print s, "is accepted \n"
      else
        str= s.gets
        print str
        if str =~ /^[GET|HEAD]/
          path= str.split(' ')[1]
          sleep(0.1)
          s.write <<EOF
HTTP/1.1 200 OK
Content-Type: text/html; charset=UTF-8
Server: http-server.rb/0.1
Content-Length: 12

this is test

EOF
          s.close
          socks.delete(s)
        end
      end
    end
  end
end