First approach, you could just read one byte at a time. Then when you find a "\n", voila you have a line.

Then you might start thinking about more efficient ways to do it if that wasn't good enough. Try to read in an 8k buffer, then parse that buffer.

I'm still not sure why you couldn't use <FILEHANDLE>, though. You're talking about using seek, and that uses a FILEHANDLE too.