function NumeroSubDirectorios(directorio: string;
ocultos, sistema, soloLectura: boolean) : integer;
var
SR: TSearchRec;
atributos: Cardinal;
begin
Result := 0;
atributos := faDirectory;
if ocultos then atributos := atributos or faHidden;
if sistema then atributos := atributos or faSysFile;
if soloLectura then atributos := atributos or faReadOnly;
directorio := IncludeTrailingPathDelimiter(directorio);
if FindFirst(directorio +'*', atributos, SR) = 0 then
begin
repeat
if (SR.Name <> '.') and (SR.Name <> '..')
and DirectoryExists(directorio + SR.Name) then
Inc(Result);
until FindNext(SR) <> 0;
SysUtils.FindClose(SR);
end;
end;