use strict;
use warnings;

my @isolist = qw(one two three four five); # should contain ISO names

while (my @workunit = splice @isolist, 0, 3) {
    my @pids;
    for (0 .. $#workunit) {
        push @pids, burncd($workunit[$_], $_);
    }
    waitpid $_, 0 for @pids;

    print "Work unit finished.\n";

    if (@isolist) {
        # perhaps a prompt here to put in new blanks
        print "Starting next round...\n";
        sleep 3;
    }
}

sub burncd {
    my ($isoname, $target) = @_;

    my $pid = fork;

    die "Cannot fork: $!" unless defined $pid;
    return $pid if $pid;

    print "Burning $isoname to cdrw$target\n";

    # burn the cd. randomized sleep just for testing.
    sleep int rand(5) + 5;

    exit;
}