anchor.diff:      {ok, State0} = remove(Sig, Fun, State),
       {reply, ok, State0};
   handle_call(stop, _From, State) -> {stop, normal, ok, State};
  +handle_call(registered,_From,State)->
  +    {reply, State,State};
   handle_call(Request, _From, State) ->
       error_logger:info_msg(?MODULE_STRING " ~p ignoring call: ~p~n",
   			  [self(), Request]),
  
positive.code:     lists:foreach(Fun, sighandler_nif:module_info(exports)).
  
  %% State management
  
  install(Sig, Fun, Ref, #state{handlers = Handlers, port = Port} = State) ->
      Installed = case sighandler_drv:status(Port, Sig) of
  		    active -> installed;
  
negative.code:     gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
  
  stop() -> gen_server:call(?SERVER, stop).
  
  registered()-> 
      State=gen_server:call(?SERVER,registered),
      State#state.handlers.
  
  %%%===================================================================
  %%% gen_server callbacks
  