code: func Register(name string, help string, f interface{}, server *chanrpc.Server) {
  	for _, c := range commands {
  		if c.name() == name {
  			log.Fatal("command %v is already registered", name)
  		}
  	}
  
  	server.Register(name, f)
  
  	c := new(ExternalCommand)
  	c._name = name
  	c._help = help
  	c.server = server
  	commands = append(commands, c)
  }
docs: // you must call the function before calling console.Init
  // goroutine not safe