fnet_socket_close()

fnet_return_t fnet_socket_close

(

fnet_socket_t

s

)

Closes an existing socket.

Parameters

s	Descriptor, identifying a socket to close.

Returns

This function returns:

• FNET_OK if no error occurs.
• FNET_ERR if an error occurs.
  The specific error code can be retrieved using the fnet_error_get().

See also

fnet_socket()

This function releases the socket descriptor s, so that further references to s fail with the error FNET_ERR_BAD_DESC.
An application should always have a matching call to the fnet_socket_close() for each successful call to the fnet_socket() to return any socket resources to the system.

For the SOCK_STREAM sockets, the SO_LINGER option controls the action of the closing, when unsent data is present on the socket and the fnet_socket_close() function is performed. This option has effect on TCP sockets only. To enable or disable the SO_LINGER option, the application should use the fnet_linger structure. This structure includes the l_onoff and the l_linger fields. If the l_onoff has a non-zero value, then the SO_LINGER is enabled. Otherwise, the SO_LINGER option is disabled. The l_linger field includes the timeout in seconds. If the SO_LINGER option is not used , the remaining data of the output buffer can be sent after the execution of the fnet_socket_close() in the background.
If a timeout expires and unsent data is present, the hard reset occurs and unsent data will be deleted.
If the SO_LINGER option is used with a zero timeout interval, the hard reset occurs immediately and unsent data will be deleted.