This statement:

    printf OUTFILE ("%08x\n", $out);
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emits an 'ASCII' (text) representation of a number. I think you want something like:

    print OUTFILE pack('L', $out);
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which emits a more traditional 'binary' representation. See the documentation on pack for details on what formats for numbers are available.

perl's binmode has nothing to do with how numbers are printed but with how perl converts characters to octet sequences (bytes). That said, you'll want to use binmode when printing data generated from pack since pack produces binary data and not text.