my $counter;

init_timer();

while(1)
{
    select(undef, undef, undef, 0.5);
    print "$counter " . scalar(localtime) . "\n";
}


sub init_timer
{
    $counter = 0;
    $SIG{ALRM} = \&tick;
    alarm(1);
}

sub tick
{
    alarm(1);
    $counter++;
}