I hear what you're saying 

sub handle_connection {
    my ($event) = @_;

    my $socket = $event->w()->fd();
    my $client = $socket->accept();
    print "Someone connected $client\n";

    ## Set up a callback to handle each line of input...
    Event->io(
        fd => $client,
        cb => sub { handle_input(@_) },
        poll => 'r',
    );
}

sub handle_input {
    my ($event) = @_;

    my $fd = $event->w()->fd();
    if ( eof($fd) ) {
        $event->w()->cancel();
        return;
    }

    print "I heard: " . <$fd> ;
}

./example4.pl &
echo "Look out" | nc localhost 2000
Someone connected IO::Socket::INET=GLOB(0x82e6a94)
I heard: Look out
Finished