sendKeepAlive

Name

sendKeepAlive -- Sends a keep-alive packet to a persistently connected RSPD.

Synopsis

$err = $node->sendKeepAlive();

Description

This function sends a small keep-alive packet to an established persistent connection. This means that the persistent parameter of the constructor must have been set to 1, and a connection must have already been made with connect. If either is not true, this function will fail.

If persistent connections are desired but the time between gathering new data may be large, this function can be used to guarantee that the connection is still active. If the keep-alive packet cannot be sent successfully, this function will return with an appropriate error message.

Returns

Returns -1 if an error occurred, or 0 otherwise. In case of error, the program will croak() with an appriopriate message.