close()

The close() call shuts down the socket associated with the socket descriptor s and frees resources allocated to the socket. If s refers to an open TCP connection, the connection is closed. If a stream socket is closed when there is input data queued, the TCP connection is reset, not cleanly closed.

If you specify 0 on SO_LINGER on the setsockopt() call, the data is canceled and the CLOSE is immediately returned. If you do not specify a value for SO_LINGER on the setsockopt() call, the CLOSE returns and TCP/IP tries to immediately resend the data.

Note: Issue a shutdown() call before issuing a close() call for any socket.

#include <manifest.h>
#include <socket.h>
int close(int s)

Parameter: Description
s: Descriptor of the socket to be closed

Return values

The value 0 indicates success; the value -1 indicates an error. Errno identifies the specific error.

Errno: Description
EBADF: The s parameter is not a valid socket descriptor.

Related calls

accept(), getsockopt(), setsockopt(), socket()