1.\" Copyright (c) 1983, 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" from: @(#)socketpair.2 6.4 (Berkeley) 3/10/91 33.\" $Id: socketpair.2,v 1.4 1993/11/29 21:25:44 jtc Exp $ 34.\" 35.Dd March 10, 1991 36.Dt SOCKETPAIR 2 37.Os BSD 4.2 38.Sh NAME 39.Nm socketpair 40.Nd create a pair of connected sockets 41.Sh SYNOPSIS 42.Fd #include <sys/types.h> 43.Fd #include <sys/socket.h> 44.Ft int 45.Fn socketpair "int d" "int type" "int protocol" "int *sv" 46.Sh DESCRIPTION 47The 48.Fn socketpair 49call creates an unnamed pair of connected sockets in 50the specified domain 51.Fa d , 52of the specified 53.Fa type , 54and using the optionally specified 55.Fa protocol . 56The descriptors used in referencing the new sockets 57are returned in 58.Fa sv Ns [0] 59and 60.Fa sv Ns [1] . 61The two sockets are indistinguishable. 62.Sh DIAGNOSTICS 63A 0 is returned if the call succeeds, -1 if it fails. 64.Sh ERRORS 65The call succeeds unless: 66.Bl -tag -width Er 67.It Bq Er EMFILE 68Too many descriptors are in use by this process. 69.It Bq Er EAFNOSUPPORT 70The specified address family is not supported on this machine. 71.It Bq Er EPROTONOSUPPORT 72The specified protocol is not supported on this machine. 73.It Bq Er EOPNOSUPPORT 74The specified protocol does not support creation of socket pairs. 75.It Bq Er EFAULT 76The address 77.Fa sv 78does not specify a valid part of the 79process address space. 80.Sh SEE ALSO 81.Xr read 2 , 82.Xr write 2 , 83.Xr pipe 2 84.Sh BUGS 85This call is currently implemented only for the 86.Tn UNIX 87domain. 88.Sh HISTORY 89The 90.Fn socketpair 91function call appeared in 92.Bx 4.2 . 93