$server   = 'some-broker.example.com';
$port     = 1883;
$clientId = 'test-publisher';

$mqtt = new \PhpMqtt\Client\MqttClient($server, $port, $clientId);
$mqtt->connect();
$mqtt->publish('php-mqtt/client/test', 'Hello World!', 0);
$mqtt->disconnect();

$server   = 'some-broker.example.com';
$port     = 1883;
$clientId = 'test-subscriber';

$mqtt = new \PhpMqtt\Client\MqttClient($server, $port, $clientId);
$mqtt->connect();
$mqtt->subscribe('php-mqtt/client/test', function ($topic, $message) {
    echo sprintf("Received message on topic [%s]: %s\n", $topic, $message);
}, 0);
$mqtt->loop(true);
$mqtt->disconnect();

pcntl_async_signals(true);

$clientId = 'test-subscriber';

$mqtt = new \PhpMqtt\Client\MqttClient($server, $port, $clientId);
pcntl_signal(SIGINT, function (int $signal, $info) use ($mqtt) {
    $mqtt->interrupt();
});
$mqtt->connect();
$mqtt->subscribe('php-mqtt/client/test', function ($topic, $message) {
    echo sprintf("Received message on topic [%s]: %s\n", $topic, $message);
}, 0);
$mqtt->loop(true);
$mqtt->disconnect();

$mqtt = new \PhpMqtt\Client\MqttClient(
    $server, 
    $port, 
    $clientId,
    \PhpMqtt\Client\MqttClient::MQTT_3_1,
    new \PhpMqtt\Client\Repositories\MemoryRepository(),
    new Logger()
);

$mqtt = new \PhpMqtt\Client\MqttClient($server, $port, $clientId);

$connectionSettings = (new \PhpMqtt\Client\ConnectionSettings)
    ->setConnectTimeout(3)
    ->setUseTls(true)
    ->setTlsSelfSignedAllowed(true);
    
$mqtt->connect($connectionSettings, true);

$connectionSettings = (new \PhpMqtt\Client\ConnectionSettings)

    // The username used for authentication when connecting to the broker.
    ->setUsername(null)
    
    // The password used for authentication when connecting to the broker.
    ->setPassword(null)
    
    // The connect timeout defines the maximum amount of seconds the client will try to establish
    // a socket connection with the broker. The value cannot be less than 1 second.
    ->setConnectTimeout(60)
    
    // The socket timeout is the maximum amount of idle time in seconds for the socket connection.
    // If no data is read or sent for the given amount of seconds, the socket will be closed.
    // The value cannot be less than 1 second.
    ->setSocketTimeout(5)
    
    // The resend timeout is the number of seconds the client will wait before sending a duplicate
    // of pending messages without acknowledgement. The value cannot be less than 1 second.
    ->setResendTimeout(10)
    
    // This flag determines whether the client will try to reconnect automatically
    // if it notices a disconnect while sending data.
    // The setting cannot be used together with the clean session flag.
    ->setReconnectAutomatically(false)
    
    // Defines the maximum number of reconnect attempts until the client gives up.
    // This setting is only relevant if setReconnectAutomatically() is set to true.
    ->setMaxReconnectAttempts(3)
    
    // The keep alive interval is the number of seconds the client will wait without sending a message
    // until it sends a keep alive signal (ping) to the broker. The value cannot be less than 1 second
    // and may not be higher than 65535 seconds. A reasonable value is 10 seconds (the default).
    ->setKeepAliveInterval(10)
    
    // If the broker should publish a last will message in the name of the client when the client
    // disconnects abruptly, this setting defines the topic on which the message will be published.
    //
    // A last will message will only be published if both this setting as well as the last will
    // message are configured.
    ->setLastWillTopic(null)
    
    // If the broker should publish a last will message in the name of the client when the client
    // disconnects abruptly, this setting defines the message which will be published.
    //
    // A last will message will only be published if both this setting as well as the last will
    // topic are configured.
    ->setLastWillMessage(null)
    
    // The quality of service level the last will message of the client will be published with,
    // if it gets triggered.
    ->setLastWillQualityOfService(0)
    
    // This flag determines if the last will message of the client will be retained, if it gets
    // triggered. Using this setting can be handy to signal that a client is offline by publishing
    // a retained offline state in the last will and an online state as first message on connect.
    ->setRetainLastWill(false)
    
    // This flag determines if TLS should be used for the connection. The port which is used to
    // connect to the broker must support TLS connections.
    ->setUseTls(false)
    
    // This flag determines if the peer certificate is verified, if TLS is used.
    ->setTlsVerifyPeer(true)
    
    // This flag determines if the peer name is verified, if TLS is used.
    ->setTlsVerifyPeerName(true)
    
    // This flag determines if self signed certificates of the peer should be accepted.
    // Setting this to TRUE implies a security risk and should be avoided for production
    // scenarios and public services.
    ->setTlsSelfSignedAllowed(false)
    
    // The path to a Certificate Authority certificate which is used to verify the peer
    // certificate, if TLS is used.
    ->setTlsCertificateAuthorityFile(null)
    
    // The path to a directory containing Certificate Authority certificates which are
    // used to verify the peer certificate, if TLS is used.
    ->setTlsCertificateAuthorityPath(null)
    
    // The path to a client certificate file used for authentication, if TLS is used.
    //
    // The client certificate must be PEM encoded. It may optionally contain the
    // certificate chain of issuers.
    ->setTlsClientCertificateFile(null)
    
    // The path to a client certificate key file used for authentication, if TLS is used.
    //
    // This option requires ConnectionSettings::setTlsClientCertificateFile() to be used as well.
    ->setTlsClientCertificateKeyFile(null)
    
    // The passphrase used to decrypt the private key of the client certificate,
    // which in return is used for authentication, if TLS is used.
    //
    // This option requires ConnectionSettings::setTlsClientCertificateFile() and
    // ConnectionSettings::setTlsClientCertificateKeyFile() to be used as well.
    ->setTlsClientCertificateKeyPassphrase(null);