socketpair

SOCKETPAIR(2)             OpenBSD Programmer's Manual            SOCKETPAIR(2)

NAME

     socketpair - create a pair of connected sockets

SYNOPSIS

     #include <sys/types.h>
     #include <sys/socket.h>

     int
     socketpair(int d, int type, int protocol, int *sv);

DESCRIPTION

     The socketpair() call creates an unnamed pair of connected sockets in the
     specified domain d, of the specified type, and using the optionally
     specified protocol.  The descriptors used in referencing the new sockets
     are returned in sv[0] and sv[1].  The two sockets are indistinguishable.

RETURN VALUES

     A 0 is returned if the call succeeds, -1 if it fails.

ERRORS

     The call succeeds unless:

     [EMFILE]           Too many descriptors are in use by this process.

     [EAFNOSUPPORT]     The specified address family is not supported on this
                        machine.

     [EPROTONOSUPPORT]  The specified protocol is not supported on this
                        machine.

     [EOPNOTSUPP]       The specified protocol does not support creation of
                        socket pairs.

     [EFAULT]           The address sv does not specify a valid part of the
                        process address space.

     [ENFILE]           The system file table is full.

SEE ALSO

     pipe(2), read(2), write(2)

STANDARDS

     The socketpair() function conforms to X/Open Portability Guide Issue 4,
     Version 2 (``XPG4.2'').

HISTORY

     The socketpair() function call appeared in 4.2BSD.

BUGS

     This call is currently implemented only for the LOCAL domain.  Many
     operating systems only accept a protocol of PF_UNSPEC, so that should be
     used instead of PF_LOCAL for maximal portability.

OpenBSD 5.1                    November 6, 2011                    OpenBSD 5.1