http://www.perlmonks.org?node_id=107384


in reply to a few basic questions

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 Section Seekers of Perl Wisdom