bsd man page for shutdown

SHUTDOWN(2)							System Calls Manual						       SHUTDOWN(2)

NAME
       shutdown - shut down part of a full-duplex connection

SYNOPSIS
       shutdown(s, how)
       int s, how;

DESCRIPTION
       The  shutdown  call causes all or part of a full-duplex connection on the socket associated with s to be shut down.  If how is 0, then fur-
       ther receives will be disallowed.  If how is 1, then further sends will be disallowed.  If how is 2, then further sends and  receives  will
       be disallowed.

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

ERRORS
       The call succeeds unless:

       [EBADF]	      S is not a valid descriptor.

       [ENOTSOCK]     S is a file, not a socket.

       [ENOTCONN]     The specified socket is not connected.

SEE ALSO
       connect(2), socket(2)

4.2 Berkeley Distribution					   May 15, 1985 						       SHUTDOWN(2)