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.\"     $Id: shutdown.2,v 1.1.1.1 1999/03/21 22:52:23 freitag Exp $
.\"
.\" Modified Sat Jul 24 09:57:55 1993 by Rik Faith <faith@cs.unc.edu>
.\" Modified Tue Oct 22 22:04:51 1996 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified 1998 by Andi Kleen
.\"
.TH SHUTDOWN 2 2012-09-06 "Linux" "Linux Programmer's Manual"
.SH NAME
shutdown \- shut down part of a full-duplex connection
.SH SYNOPSIS
.B #include <sys/socket.h>
.sp
.BI "int shutdown(int " sockfd ", int " how );
.SH DESCRIPTION
The
.BR shutdown ()
call causes all or part of a full-duplex connection on the socket
associated with
.I sockfd
to be shut down.
If
.I how
is
.BR SHUT_RD ,
further receptions will be disallowed.
If
.I how
is
.BR SHUT_WR ,
further transmissions will be disallowed.
If
.I how
is
.BR SHUT_RDWR ,
further receptions and transmissions will be disallowed.
.SH RETURN VALUE
On success, zero is returned.
On error, \-1 is returned, and
.I errno
is set appropriately.
.SH ERRORS
.TP
.B EBADF
.I sockfd
is not a valid descriptor.
.TP
.B EINVAL
An invalid value was specified in
.IR how
(but see BUGS).
.TP
.B ENOTCONN
The specified socket is not connected.
.TP
.B ENOTSOCK
.I sockfd
is a file, not a socket.
.SH CONFORMING TO
POSIX.1-2001, 4.4BSD (the
.BR shutdown ()
function call first appeared in 4.2BSD).
.SH NOTES
The constants
.BR SHUT_RD ,
.BR SHUT_WR ,
.B SHUT_RDWR
have the value 0, 1, 2,
respectively, and are defined in
.I <sys/socket.h>
since glibc-2.1.91.
.SH BUGS
As currently implemented,
checks for the validity of
.I how
are done in domain-specific code, and not all domains perform these checks.
.\" FIXME .
.\" https://bugzilla.kernel.org/show_bug.cgi?id=47111
Most notably, UNIX domain sockets simply ignore invalid values;
this may change in the future.
.SH SEE ALSO
.BR connect (2),
.BR socket (2),
.BR socket (7)
.SH COLOPHON
This page is part of release 3.74 of the Linux
.I man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
\%http://www.kernel.org/doc/man\-pages/.