B versus b

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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Re: B versus b by Aristotle (Chancellor) on Nov 03, 2002 at 14:36 UTC
++ for pointing out the `B` vs `b` concern, but you're wrong about vec. And that code is an eval $REDFLAG;, you should do it thusly: `my ($ver, $hlen, $tos, $len) = map pack "B", unpack "A4A4A8A16", unpack "B", $foo;` However, that will not honour the network byte ordering in `$len`. Makeshifts last the longest.	[reply] [d/l]