man2/shutdown.2

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  34 .\"     $Id: shutdown.2,v 1.1.1.1 1999/03/21 22:52:23 freitag Exp $
  35 .\"
  36 .\" Modified Sat Jul 24 09:57:55 1993 by Rik Faith <faith@cs.unc.edu>
  37 .\" Modified Tue Oct 22 22:04:51 1996 by Eric S. Raymond <esr@thyrsus.com>
  38 .\" Modified 1998 by Andi Kleen
  39 .\"
  40 .TH SHUTDOWN 2 2018-04-30 "Linux" "Linux Programmer's Manual"
  41 .SH NAME
  42 shutdown \- shut down part of a full-duplex connection
  43 .SH SYNOPSIS
  44 .B #include <sys/socket.h>
  45 .PP
  46 .BI "int shutdown(int " sockfd ", int " how );
  47 .SH DESCRIPTION
  48 The
  49 .BR shutdown ()
  50 call causes all or part of a full-duplex connection on the socket
  51 associated with
  52 .I sockfd
  53 to be shut down.
  54 If
  55 .I how
  56 is
  57 .BR SHUT_RD ,
  58 further receptions will be disallowed.
  59 If
  60 .I how
  61 is
  62 .BR SHUT_WR ,
  63 further transmissions will be disallowed.
  64 If
  65 .I how
  66 is
  67 .BR SHUT_RDWR ,
  68 further receptions and transmissions will be disallowed.
  69 .SH RETURN VALUE
  70 On success, zero is returned.
  71 On error, \-1 is returned, and
  72 .I errno
  73 is set appropriately.
  74 .SH ERRORS
  75 .TP
  76 .B EBADF
  77 .I sockfd
  78 is not a valid file descriptor.
  79 .TP
  80 .B EINVAL
  81 An invalid value was specified in
  82 .IR how
  83 (but see BUGS).
  84 .TP
  85 .B ENOTCONN
  86 The specified socket is not connected.
  87 .TP
  88 .B ENOTSOCK
  89 The file descriptor
  90 .I sockfd
  91 does not refer to a socket.
  92 .SH CONFORMING TO
  93 POSIX.1-2001, POSIX.1-2008, 4.4BSD
  94 .RB ( shutdown ()
  95 first appeared in 4.2BSD).
  96 .SH NOTES
  97 The constants
  98 .BR SHUT_RD ,
  99 .BR SHUT_WR ,
 100 .B SHUT_RDWR
 101 have the value 0, 1, 2,
 102 respectively, and are defined in
 103 .I <sys/socket.h>
 104 since glibc-2.1.91.
 105 .SH BUGS
 106 Checks for the validity of
 107 .I how
 108 are done in domain-specific code,
 109 and before Linux 3.7 not all domains performed these checks.
 110 .\" https://bugzilla.kernel.org/show_bug.cgi?id=47111
 111 Most notably, UNIX domain sockets simply ignored invalid values.
 112 This problem was fixed for UNIX domain sockets
 113 .\" commit fc61b928dc4d72176cf4bd4d30bf1d22e599aefc
 114 .\" and for DECnet sockets in commit 46b66d7077b89fb4917ceef19b3f7dd86055c94a
 115 in Linux 3.7.
 116 .SH SEE ALSO
 117 .BR close (2),
 118 .BR connect (2),
 119 .BR socket (2),
 120 .BR socket (7)