my $expect = 'eyecatcher';
my $record;
while (1) {
  if ($expect eq 'eyecatcher' || $expect eq 'eyecatcher_after_record') {
    if (read_two_bytes() eq '==') {
      process_record($record) if $expect eq 'eyecatcher_after_record';
      $record = undef;
      $expect = 'length';
    }
    else { die "expected eyecatcher" }
  }
  elsif ($expect eq 'length') {
    my $length = read_two_bytes();
    $record = read_bytes($length);
    $expect = 'eyecater_after_record';
  }
}