SHUTDOWN(2) System Calls Manual SHUTDOWN(2)
shutdown -- shut down part of a full-duplex connection
Standard C Library (libc, -lc)
shutdown(int s, int how);
The shutdown() 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:
[EBADF] s is not a valid descriptor.
[EINVAL] The how argument is invalid.
[ENOTCONN] The specified socket is not connected.
[ENOTSOCK] s is a file, not a socket.
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'').
NetBSD 6.1.5 August 18, 2002 NetBSD 6.1.5