Thanks for the information on how to actually read files - it seems like I didn't make my problem clear enough :) I already know all the basics (and some more) about file handling in Perl. But what I do not know is, how one in "general" handles reading stuff from files that are structured as records or even less structured (i.e. records of different length). Your proposal to hardcode the record size strikes me as a bad idea, since I have to recalculate the record size each time I find some new information about the file.
As I watch this discussion unfold, it comes to me that maybe my first kludgy idea of parsing the string passed to unpack() wasn't that bad after all ...