my $pid =fork;
$SIG{INT} = sub {
    # got ctrl-c, sending sigterm to child
    kill 15, $pid;
    exit;
};
if ($pid) {#parent
    waitpid($pid,0);
}
elsif (defined $pid) {
    for (5 .. 10) {
        print "sleeping $_\n";
        system("sleep $_");
    }
    exit;
}
else { ... }