$|++; # flush buffers;

# set a common variable to 1, the parent will leave its 
# copy alone but the child will increment its copy.
my $in++;

defined(my $pid = fork) or die "Can't fork $!";

if ($pid) {
    # do parent stuff
    print "I am the parent!\n\n";
    sleep 2;
    print "I am going to count to 10\n";
    for (1..10) {
        print "$_ Do as I say!\n";
        sleep $in; 
    }
    print "You're grounded!\n";
    # kill INT, $pid;  # uncomment this to kill child process
}
else {
    # do child stuff
    sleep $in;
    print "I am the child!\n\n";
    sleep $in++;    print "No!\n";
    sleep $in++;    print "No!\n";
    sleep $in++;    print "No!\n";
    sleep $in++;    print "No!\n";
    sleep $in++;
    print "I am not deaf, I'm ignoring you!\n";
}

die "End of process \$pid = $pid \n\n";