DeviceIoControl($fh,
    FSCTL_GET_RETRIEVAL_POINTERS,
    $inBuf,length($inBuf),
    $outBuf,length($outBuf),
    $dwBytesReturned,
    []);
 my $error = Win32::GetLastError();
  print "error-no: $error\n";
  warn "DeviceIoControl->Call: ", Win32::FormatMessage($error) if ($error);