my $pid = fork;
    die "Fork failed: $!" unless defined $pid;
    unless ($pid) {
        system "C:\\block.exe";
        die "Command failed with exit code ", $? >> 8 if $?;
        exit;
    }
    print "processing second line...\n"; 

##</code><code>##

    my $pid = fork;
    die "Fork failed: $!" unless defined $pid;
    unless ($pid) {
        exec "C:\\block.exe";
        die "exec failed: $!";
    }
    print "processing second line...\n";