SHUTDOWN(2) System Calls Manual SHUTDOWN(2)

shutdown — shut down part of a full-duplex connection

Standard C Library (libc, -lc)

#include <sys/socket.h>

int
shutdown(int s, int how);

The () call causes all or part of a full-duplex connection on the socket associated with s to be shut down. The how argument specifies which part of the connection will be shut down. Permissible values are:

SHUT_RD
further receives will be disallowed.
SHUT_WR
further sends will be disallowed.
SHUT_RDWR
further sends and receives will be disallowed.

A 0 is returned if the call succeeds, -1 if it fails.

The call succeeds unless:

[]
s is not a valid descriptor.
[]
The how argument is invalid.
[]
The specified socket is not connected.
[]
s is a file, not a socket.

connect(2), socket(2)

The shutdown() function call appeared in 4.2BSD. The how arguments used to be simply 0, 1, and 2, but now have named values as specified by X/Open Portability Guide Issue 4 (“XPG4”).

August 18, 2002 NetBSD 11.0