anchor.diff:      io_lib:format("~4..0w-~2..0w-~2..0w ~2..0w:~2..0w:~2..0w",
   		  [Year, Month, Day, Hour, Minute, Second]).
   
  -isnumeric(Number) ->
  +isnumeric(Number) when list(Number) ->
       case regexp:first_match(Number, "^[0-9]+$") of
   	{match, _, _} ->
   	    true;
   	_ ->
   	    false
  -    end.
  +    end;
  +isnumeric(_) ->
  +    false.
   
   digit(Digit) when integer(Digit), Digit >= $0, Digit =< $9 ->
       Digit - $0;
  
positive.code:     [];
  concat([A | B], Separator) ->
      A ++ Separator ++ concat(B, Separator).
  
negative.code: -module(util).
  -export([timestamp/0, sec_to_date/1, isnumeric/1, regexp_rewrite/2, casecompare/2, casegrep/2, join/2, concat/2, count/1]).
  
  timestamp() ->
      {Megasec, Sec, _} = now(),
  