In addition to the problems Aristotle outlined above, there is one more problem. The functions unpack("b") and vec() unpack the bits in the wrong order within bytes.

If you unpack("B*", $foo), you will get all the bits (as a string) in the right order. Here is one way to get your final answer, although I'm not sure that eval "0b$_" is the best solution:

($ver, $hlen, $tos, $len) = map { eval "0b$_" } unpack "A4A4A8A16", un
+pack("B*", $a);

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In reply to B versus b by Thelonius
in thread IP Header by Anonymous Monk

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