1.\" $NetBSD: socketpair.2,v 1.5 1995/02/27 12:38:00 cgd 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 June 4, 1993 37.Dt SOCKETPAIR 2 38.Os BSD 4.2 39.Sh NAME 40.Nm socketpair 41.Nd create a pair of connected sockets 42.Sh SYNOPSIS 43.Fd #include <sys/types.h> 44.Fd #include <sys/socket.h> 45.Ft int 46.Fn socketpair "int d" "int type" "int protocol" "int *sv" 47.Sh DESCRIPTION 48The 49.Fn socketpair 50call creates an unnamed pair of connected sockets in 51the specified domain 52.Fa d , 53of the specified 54.Fa type , 55and using the optionally specified 56.Fa protocol . 57The descriptors used in referencing the new sockets 58are returned in 59.Fa sv Ns [0] 60and 61.Fa sv Ns [1] . 62The two sockets are indistinguishable. 63.Sh DIAGNOSTICS 64A 0 is returned if the call succeeds, -1 if it fails. 65.Sh ERRORS 66The call succeeds unless: 67.Bl -tag -width Er 68.It Bq Er EMFILE 69Too many descriptors are in use by this process. 70.It Bq Er EAFNOSUPPORT 71The specified address family is not supported on this machine. 72.It Bq Er EPROTONOSUPPORT 73The specified protocol is not supported on this machine. 74.It Bq Er EOPNOSUPPORT 75The specified protocol does not support creation of socket pairs. 76.It Bq Er EFAULT 77The address 78.Fa sv 79does not specify a valid part of the 80process address space. 81.Sh SEE ALSO 82.Xr read 2 , 83.Xr write 2 , 84.Xr pipe 2 85.Sh BUGS 86This call is currently implemented only for the 87.Tn UNIX 88domain. 89.Sh HISTORY 90The 91.Fn socketpair 92function call appeared in 93.Bx 4.2 . 94