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.\"     @(#)shutdown.2	8.1 (Berkeley) 6/4/93
.\" $FreeBSD: src/lib/libc/sys/shutdown.2,v 1.7.2.7 2001/12/14 18:34:01 ru Exp $
.\" $DragonFly: src/lib/libc/sys/shutdown.2,v 1.2 2003/06/17 04:26:47 dillon Exp $
.\"
.Dd February 27, 2001
.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/types.h
.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 the file descriptor
.Fa s
to be shut down.
The
.Fa how
argument specifies the type of shutdown.
Possible values are:
.Bl -tag -width SHUT_RDWR
.It Dv SHUT_RD
further receives will be disallowed.
.It Dv SHUT_WR
further sends will be disallowed.
.It Dv SHUT_RDWR
further sends and receives will be disallowed.
.El
.Sh RETURN VALUES
.Rv -std shutdown
.Sh ERRORS
The
.Fn shutdown
call fails if:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Fa s
argument is not a valid file descriptor.
.It Bq Er EINVAL
The
.Fa how
argument is invalid.
.It Bq Er ENOTCONN
The socket is not connected.
.It Bq Er ENOTSOCK
The
.Fa s
argument does not refer to a socket.
.El
.Sh SEE ALSO
.Xr connect 2 ,
.Xr socket 2
.Sh STANDARDS
The
.Fn shutdown
function is expected to comply with
.St -p1003.1g-2000 ,
when finalized.
.Sh HISTORY
The
.Fn shutdown
function call appeared in
.Bx 4.2 .
The
.Dv SHUT_RD , SHUT_WR ,
and
.Dv SHUT_RDWR
constants appeared in
.St -p1003.1g-2000 .