1.\" $NetBSD: socketpair.2,v 1.14 2002/02/08 01:28:22 ross Exp $ 2.\" 3.\" Copyright (c) 1983, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)socketpair.2 8.1 (Berkeley) 6/4/93 35.\" 36.Dd October 16, 2001 37.Dt SOCKETPAIR 2 38.Os 39.Sh NAME 40.Nm socketpair 41.Nd create a pair of connected sockets 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.Fd #include \*[Lt]sys/socket.h\*[Gt] 46.Ft int 47.Fn socketpair "int d" "int type" "int protocol" "int *sv" 48.Sh DESCRIPTION 49The 50.Fn socketpair 51call creates an unnamed pair of connected sockets in 52the specified domain 53.Fa d , 54of the specified 55.Fa type , 56and using the optionally specified 57.Fa protocol . 58The descriptors used in referencing the new sockets 59are returned in 60.Fa sv Ns [0] 61and 62.Fa sv Ns [1] . 63The two sockets are indistinguishable. 64.Sh RETURN VALUES 65A 0 is returned if the call succeeds, -1 if it fails. 66.Sh ERRORS 67The call succeeds unless: 68.Bl -tag -width Er 69.It Bq Er EMFILE 70Too many descriptors are in use by this process. 71.It Bq Er ENFILE 72The system file table is full. 73.It Bq Er EAFNOSUPPORT 74The specified address family is not supported on this machine. 75.It Bq Er EPROTONOSUPPORT 76The specified protocol is not supported on this machine. 77.It Bq Er EOPNOTSUPP 78The specified protocol does not support creation of socket pairs. 79.It Bq Er EFAULT 80The address 81.Fa sv 82does not specify a valid part of the 83process address space. 84.El 85.Sh SEE ALSO 86.Xr pipe 2 , 87.Xr read 2 , 88.Xr write 2 89.Sh HISTORY 90The 91.Fn socketpair 92function call appeared in 93.Bx 4.2 . 94.Sh BUGS 95This call is currently implemented only for the 96.Ux 97domain. 98