Server Manager and the Unix socket server

In order to be able to use stream_socket_client() to connect to a socket server, we need to first create the server with stream_socket_server(). The principle is identical to what we saw in the previous chapter when explaining the example with a simple HTTP server, made just using stream_socket_server(), stream_socket_accept(), and StreamSelectLoop:

class ServerManager extends Command { 
  // ... 
  private $statusSubject; 
  private $servers = []; 
 
  protected function execute($input, $output) { 
    // ... 
    @unlink($this->unixSocketFile); 
    $address = "unix://" . $this->unixSocketFile; 
    $server = stream_socket_server($address, $errno, $errMsg); 
    stream_set_blocking($server, 0); 
 
    $this->loop->addReadStream($server, function() use ($server) { 
      $client = stream_socket_accept($server); 
      $server = new GameServerStreamEndpoint($client,...