defend from -> :() { :&:; } ;:
Rob
bitabyss at gmail.com
Tue Oct 23 07:06:47 PDT 2007
Mike Jeays wrote:
>>> Please do not try to execute this: :() { :&:; } ;: on your BSD machine.
>> What does it do?
>
> It is easier to understand when you replace the ":" by a more conventional
> subroutine name.
>
> myproc () {
> myproc &
> myproc
> }
>
> myproc
>
> It recursively generates useless processes that clog up the machine. Mine
> ground to a halt and froze after a few seconds.
Interesting, if not annoying ;) Thanks for the explanation, Mike. I edited /etc/login.conf and changed maxproc=unlimited to maxproc=200. Then tried it. Took a second or so to start spewing "Cannot fork: Resource temporarily unavailable". I'd opened a 2nd session, and ps wasn't even able to give me full info on what was happening. Luckily, is was easily interruptible and the system seemed to recover.
-Rob
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