When I run this snippet, it runs forever without out ever tripping the sub routine. 
$SIG{ALRM} = sub {print "checking;};
alarm 2;
while (1) {1};

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I would expect this to print out "checking" after about two seconds and then run forever, but it never calls the sub.
I've obviously made a simple, newbie mistake somewhere, but I can't see it.

In reply to How to use alarm? by stephenp

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