redhat man page for socketpair

SOCKETPAIR(2)						     Linux 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[2]);

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  indistin-
       guishable.

RETURN VALUE
       On success, zero is returned.  On error, -1 is returned, and errno is set appropriately.

ERRORS
       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.

CONFORMING TO
       4.4BSD  (the  socketpair  function call appeared in 4.2BSD). Generally portable to/from non-BSD systems supporting clones of the BSD socket
       layer (including System V variants).

NOTES
       On Linux, the only supported domain for this call is AF_UNIX (or synonymously, AF_LOCAL).  (Most implementations  have  the  same  restric-
       tion.)

SEE ALSO
       read(2), write(2), pipe(2), socket(2), unix(7)

BSD Man Page							    1993-07-24							     SOCKETPAIR(2)