.\" Copyright (c) 1983, 1991 The Regents of the University of California. .\" All rights reserved. .\" .\" SPDX-License-Identifier: BSD-4-Clause-UC .\" .\" $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 .\" Modified Tue Oct 22 22:04:51 1996 by Eric S. Raymond .\" Modified 1998 by Andi Kleen .\" .TH shutdown 2 2024-05-02 "Linux man-pages (unreleased)" .SH NAME shutdown \- shut down part of a full-duplex connection .SH LIBRARY Standard C library .RI ( libc ", " \-lc ) .SH SYNOPSIS .nf .B #include .P .BI "int shutdown(int " sockfd ", int " how ); .fi .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 to indicate the error. .SH ERRORS .TP .B EBADF .I sockfd is not a valid file descriptor. .TP .B EINVAL An invalid value was specified in .I how (but see BUGS). .TP .B ENOTCONN The specified socket is not connected. .TP .B ENOTSOCK The file descriptor .I sockfd does not refer to a socket. .SH STANDARDS POSIX.1-2008. .SH HISTORY POSIX.1-2001, 4.4BSD (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 since glibc-2.1.91. .SH BUGS Checks for the validity of .I how are done in domain-specific code, and before Linux 3.7 not all domains performed these checks. .\" https://bugzilla.kernel.org/show_bug.cgi?id=47111 Most notably, UNIX domain sockets simply ignored invalid values. This problem was fixed for UNIX domain sockets .\" commit fc61b928dc4d72176cf4bd4d30bf1d22e599aefc .\" and for DECnet sockets in commit 46b66d7077b89fb4917ceef19b3f7dd86055c94a in Linux 3.7. .SH SEE ALSO .BR close (2), .BR connect (2), .BR socket (2), .BR socket (7)