Or rather 

substr 
    substr(do { _utf8_off(my $internal = $_); $internal }, 0, 4) 
    . chr(0) x 4, 0, 4;

[download]

How's that! (for out-pedanting the pedant! (Always assuming I got it right :)

From perlfunc:pack (I'm too tired to fix up the link):

a A string with arbitrary binary data, will be null padded.
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

In reply to Re^2: Mysteries of unpack("a", ...) by BrowserUk
in thread Mysteries of unpack("a", ...) by pspinler

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