table of contents
| NNG_LISTEN(3) | NNG Reference Manual | NNG_LISTEN(3) |
NAME¶
nng_listen - create and start listener
SYNOPSIS¶
#include <nng/nng.h> int nng_listen(nng_socket s, const char *url, nng_listener *lp, int flags);
DESCRIPTION¶
The nng_listen() function creates a newly initialized nng_listener object, associated with socket s, and configured to listen at the address specified by url, and starts it. If the value of lp is not NULL, then the newly created listener is stored at the address indicated by lp.
Listeners are used to accept connections initiated by remote dialers. An incoming connection generally results in an nng_pipe object being created and attached to the socket s. Unlike dialers, listeners generally can create many pipes, which may be open concurrently.
The flags argument is ignored, but reserved for future use.
Tip
While it is convenient to think of listeners as servers, the
relationship between the listener or dialer is orthogonal to any server or
client status that might be associated with a given protocol. For example, a
req socket might have associated dialers, but might also have
associated listeners. It may even have some of each at the same time!
Because the listener is started immediately, it is generally not possible to apply extra configuration; if that is needed applications should consider using nng_listener_create() and nng_listener_start() instead.
The created listener will continue to accept new connections, associating their pipes with the socket, until either it or the socket s is closed.
RETURN VALUES¶
This function returns 0 on success, and non-zero otherwise.
ERRORS¶
NNG_EADDRINUSE
NNG_EADDRINVAL
NNG_ECLOSED
NNG_EINVAL
NNG_ENOMEM
SEE ALSO¶
nng_dial(3), nng_listener_close(3), nng_listener_create(3) nng_listener_start(3), nng_strerror(3), nng_listener(5), nng(7)
| 2024-10-11 |