anchor.diff:  accept_data_connection(#state{mode = passive} = State) ->
       {ok,State}.
   
  -
  +-spec send_ctrl_message(State, Message) -> _ when
  +      State   :: #state{},
  +      Message :: [term() | Message].
   send_ctrl_message(_S=#state{csock = Socket, verbose = Verbose}, Message) ->
       verbose(lists:flatten(Message),Verbose,send),
       ?DBG('<--ctrl ~p ---- ~s~p~n',[Socket,Message,_S]),
  
positive.code:          {ftp_extension, ValidateFtpExtension, false, ?FTP_EXT_DEFAULT}],
      validate_options(Options, ValidOptions, []).
  
  socket_options(Options) ->
      CtrlOpts = proplists:get_value(sock_ctrl, Options, []),
      DataActOpts = proplists:get_value(sock_data_act, Options, CtrlOpts),
  
negative.code: %%--------------------------------------------------------------------------
  %% Help functions to handle_ctrl_result
  %%--------------------------------------------------------------------------
  
  -spec ctrl_result_response(Status, State, Error) -> Result when
        Status :: ctrl_status_operation() | {ctrl_status_operation(), _},
        State  :: #state{},
        Error  :: {error, Reason},
        Reason :: term(),
        Result :: {noreply, #state{}} | Error.
  ctrl_result_response(pos_compl, #state{client = From} = State, _)  ->
      gen_server:reply(From, ok),
      {noreply, State#state{client = undefined, caller = undefined}};
  