TgzHeaderRec = packed record
  text: Integer;
  time: Cardinal;
  xflags: Integer;
  os: Integer;
  extra: PChar;
  extra_len: Cardinal;
  extra_max: Cardinal;
  name: PChar;
  name_max: Cardinal;
  comment: Cardinal;
  comm_max: Cardinal;
  hcrc: Integer;
  done: Integer;
end;