can't help with the last two questions (not sure what you mean with the second), but here's the first one: 
my $counter = 0;

while(1)
{
        print "Got an even number\n" if(($counter++%2) == 0);
}

[download]
This will only print when $counter is even...

In reply to Re: a few basic questions by ozone
in thread a few basic questions by maddfisherman

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