This function checks if there is a service available at the specified port on the specified machine.
string $host - address of the host to check
string $port - port to check
string $timeout - time in seconds to wait for response from host
Important: If you run into timeout problems despite setting this parameter to a reasonably high value, you need to make sure that the configuration directive default_socket_timeout in the php.ini configuration file does not force the maximum timeout down to a lower value.
Example 54-1. Using checkPort