nng_listener_id3
Return numeric listener identifier
Usage
#include <nng/nng.h> int nng_listener_id(nng_listener l);
Overview
The nng_listener_id() function returns a positive identifier for the listener l, if it is valid. Otherwise it returns -1.
Note
A listener is considered valid if it was ever created with the nng_listener_create() or nng_listen() functions. listeners that are allocated on the stack or statically should be initialized with the macro NNG_LISTENER_INITIALIZER to ensure that they cannot be confused with a valid listener before they are created properly.
Return values
This function returns the positive value for the listener identifier, or -1 if the listener is invalid.
Errors
None.