.\"	$NetBSD: shutdown.2,v 1.15 2003/04/16 13:34:56 wiz Exp $
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.\"     @(#)shutdown.2	8.1 (Berkeley) 6/4/93
.\"
.Dd August 18, 2002
.Dt SHUTDOWN 2
.Os
.Sh NAME
.Nm shutdown
.Nd shut down part of a full-duplex connection
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/socket.h
.Ft int
.Fn shutdown "int s" "int how"
.Sh DESCRIPTION
The
.Fn shutdown
call causes all or part of a full-duplex connection on
the socket associated with
.Fa s
to be shut down.
The
.Fa how
argument specifies which part of the connection will be shut down.
Permissible values are:
.Bl -tag -width SHUT_RDWRXX -offset indent
.It SHUT_RD
further receives will be disallowed.
.It SHUT_WR
further sends will be disallowed.
.It SHUT_RDWR
further sends and receives will be disallowed.
.El
.Sh RETURN VALUES
A 0 is returned if the call succeeds, -1 if it fails.
.Sh ERRORS
The call succeeds unless:
.Bl -tag -width Er
.It Bq Er EBADF
.Fa s
is not a valid descriptor.
.It Bq Er EINVAL
The
.Fa how
argument is invalid.
.It Bq Er ENOTCONN
The specified socket is not connected.
.It Bq Er ENOTSOCK
.Fa s
is a file, not a socket.
.El
.Sh SEE ALSO
.Xr connect 2 ,
.Xr socket 2
.Sh HISTORY
The
.Fn shutdown
function call appeared in
.Bx 4.2 .
The
.Fa how
arguments used to be simply 0, 1, and 2, but now have named values
as specified by
.St -xpg4 .