use UniEvent;
 
my $tcp = UniEvent::Tcp->new;
 
$tcp->connect($host, $port, sub {
    my ($tcp, $error) = @_;
    die("cannot connect: $error\n") if $error;
    ...
});
 
$tcp->write($data, sub {
    my ($tcp, $error) = @_;
    die("writing data error: $error\n") if $error;
    ...
});
 
$tcp->read_callback(sub {
    my ($tcp, $data, $error) = @_;
    die("reading data error: $error\n") if $error;
    ...
});
 
$tcp->eof_callback(sub {
    my $tcp = shift;
    ...
});
 
$tcp->loop->run;