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Typing this :(){:|:&};: will cause system freeze.What is the reason behind this.

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It's called a fork bomb: – Dennis Williamson Aug 28 '09 at 13:09
Why did you make this a comment? – innaM Aug 28 '09 at 14:12
up vote 6 down vote accepted

defines a function called ':'

{ :|:& };

This is the function: It calls the function itself and pipes the output to the same function ":" and puts the process in the background. (Recursive invocation) with ; it ends the function definition


Calls the function and creates havoc.

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Note that many systems now enforce a limit on processes per user (by default) that protects you from the havoc. Not all systems do, however, so no sense in trying it out. – Telemachus Aug 31 '09 at 12:48

This was answered on You'll find detailed answers over there.

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Shouldn't the question be closed then? – SeanJA Aug 28 '09 at 11:23
No:… – innaM Aug 28 '09 at 11:34
That wasn't the only time it was asked and answered at SO either:… – Telemachus Aug 31 '09 at 12:47

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