I've been playing around with trying to completely remove the ability to call a specific perl function (shmget if you care). I've tried the usual tricks like:

BEGIN{*CORE::GLOBAL::shmget=sub{die}}
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And so on, but they can all be trivially circumvented by this code: BEGIN{ undef *CORE::GLOBAL::shmget }. Simply add that code after any attempts to remove shmget and shmget magically springs back to life. So now I ask you: anyone have a better idea for removing it? I'll cheerfully take XS and B:: evilness.