1.\" $NetBSD: socketpair.2,v 1.11 1999/12/02 21:42:39 kleink 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 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 <sys/types.h> 46.Fd #include <sys/socket.h> 47.Ft int 48.Fn socketpair "int d" "int type" "int protocol" "int *sv" 49.Sh DESCRIPTION 50The 51.Fn socketpair 52call creates an unnamed pair of connected sockets in 53the specified domain 54.Fa d , 55of the specified 56.Fa type , 57and using the optionally specified 58.Fa protocol . 59The descriptors used in referencing the new sockets 60are returned in 61.Fa sv Ns [0] 62and 63.Fa sv Ns [1] . 64The two sockets are indistinguishable. 65.Sh RETURN VALUES 66A 0 is returned if the call succeeds, -1 if it fails. 67.Sh ERRORS 68The call succeeds unless: 69.Bl -tag -width Er 70.It Bq Er EMFILE 71Too many descriptors are in use by this process. 72.It Bq Er ENFILE 73The system file table is full. 74.It Bq Er EAFNOSUPPORT 75The specified address family is not supported on this machine. 76.It Bq Er EPROTONOSUPPORT 77The specified protocol is not supported on this machine. 78.It Bq Er EOPNOTSUPP 79The specified protocol does not support creation of socket pairs. 80.It Bq Er EFAULT 81The address 82.Fa sv 83does not specify a valid part of the 84process address space. 85.El 86.Sh SEE ALSO 87.Xr pipe 2 , 88.Xr read 2 , 89.Xr write 2 90.Sh BUGS 91This call is currently implemented only for the 92.Ux 93domain. 94.Sh HISTORY 95The 96.Fn socketpair 97function call appeared in 98.Bx 4.2 . 99