NNG_CLOSE(3) NNG Reference Manual NNG_CLOSE(3)

nng_close - close socket

#include <nng/nng.h>
int nng_close(nng_socket s);
int nng_socket_close(nng_socket s);

The nng_socket_close() function closes the supplied socket, s. Messages that have been submitted for sending may be flushed or delivered, depending upon the transport.

The nng_close() function also does this, and is the old name for this function. The nng_close() function is considered deprecated and may be removed in the next major release.

Further attempts to use the socket after this call returns will result in NNG_ECLOSED. Threads waiting for operations on the socket when this call is executed may also return with an NNG_ECLOSED result.


Note

Closing the socket while data is in transmission will likely lead to loss
of that data. There is no automatic linger or flush to ensure that the socket send buffers have completely transmitted. It is recommended to wait a brief period after calling nng_send() or similar functions, before calling this function.

This function returns 0 on success, and non-zero otherwise.

NNG_ECLOSED

The socket s is already closed or was never opened.

nng_strerror(3), nng_options(5), nng_socket(5), nng(7)

2025-01-05