Überprüfen ob String ein korrekter Dateifilter ist

[turboPASCAL]

Würde die function noch umbenennen zB. in CheckFileDialogFilter(Filter: String):Boolean oder so.
ist soweit Ok denke ich bis auf:

Delphi-Quellcode:

function CheckFileExtensions(Extensions: String):Boolean;
var
  Ext, title, filter, s:  String;
begin
  Result := False;
  Ext := Extensions;
  while length(Ext) > 0 do begin
    title := '';
    filter := '';
    title := copy(Ext, 1, pos('|', Ext));
    if (title = '') then begin
      Result := False;
      break;
    end else Result := True;

    delete(Ext, 1, pos('|', Ext));
    if (pos('|', Ext) = 0) then begin
      filter := Ext;
      s := copy(filter, 3, length(filter));
      if Length(Filter) < 1 then begin   //  <--  ExtensionsStr = 'Textdatei (*.txt)|';
        Result := False;                 //
        break;                           //
      end;                               //
      if ((filter[1] <> '*') or  (filter[2] <>'.') or (length(s) < 1)) then begin
        Result := False;
      end
      else Result := True;
      break;
    end else begin
      filter := copy(Ext, 1, pos('|', Ext) - 1);
      s := copy(filter, 3, length(filter));
      if ((filter[1] <> '*') or  (filter[2] <>'.') or (length(s) < 1)) then begin
        Result := False;
        break;
      end else Result := True;
      delete(Ext, 1, pos('|', Ext));
    end;
  end;
end;