This question is not backup-related so thankfully I don't have to concern myself with tape drives. The code is expected to handle a specific file format (Bethesda .esm and .esp files) and therefor the filehandle is expected to point to a file on a random access media (disk drive).

The most common case would be sequentially processing the records, but I'd like to also be able to process the records out of order (e.g. skip uninteresting ones).