Although there are various parser generator modules for Perl, they are probably not the best option if speed is of paramount importance.

Maybe you could use a somewhat simpler state machine instead, i.e a set of variables that you toggle on and off depending on specific tokens you encounter in the file.  They would then indicate what section of the file you're currently in, so you could write something like 

    if ($in_section_foo) {
        if ($in_subsection_bar) {
            handle_foo_bar();
        }
        ...
    }
    ...

[download]

where handle_foo_bar() would read the appropriate number of bytes (the multi-dimesional array) and unpack them according to the pattern that applies for foo/bar.

It's hard to be more specific without knowing what exact format you're talking about.

In reply to Re: Reading binary files - program structure by almut
in thread Reading binary files - program structure by Anonymous Monk

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