This is deprecated.

Yes it is. There are better ways to integrate socket.io / websockets into a php application. My chosen one is using redis to communicate to the node process, and configuring nginx properly. You shouln't be using this.

php-socketio-broadcast

simple class to send messages from PHP to socket.io

How to use:

/**                     | server    | port */
$socketio = new SocketIO('127.0.0.1', 8080);;
/**                 | command |     data        */
if ($socketio->send('message','Hello world!')){
    echo 'we sent the message and disconnected';
} else {
    echo 'Sorry, we have a mistake :\'(';
}

Documentation https://tools.ietf.org/html/rfc6455

Initially based on https://github.com/psinetron/PHP_SocketIO_Client