gistfile1.txt

    use AnyEvent::Util;
    return sub {
        return sub {
            my $writer = $_[0]->([200, []]);
            AnyEvent::Util::run_cmd(['ls'], '>' => sub {
                $writer->write($_[0]) if defined $_[0];
                $writer->write("Closed\n") unless defined $_[0];
            })->cb(sub {
                $writer->write('End');
                my $timer; $timer = AE::timer(0.5, 0, sub {
                    $writer->close;
                    undef $timer;
                });
            });
        };
    };