Linux man pages : socketpair (2)
SOCKETPAIR(2) Linux Programmer's Manual SOCKETPAIR(2)
socketpair - create a pair of connected sockets
int socketpair(int d, int type, int protocol, int sv);
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 sock-
ets are returned in sv and sv. The two sockets are indistin-
On success, zero is returned. On error, -1 is returned, and errno is
EMFILE Too many descriptors are in use by this process.
The specified address family is not supported on this machine.
The specified protocol is not supported on this machine.
The specified protocol does not support creation of socket
EFAULT The address sv does not specify a valid part of the process
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).
On Linux, the only supported domain for this call is AF_UNIX (or syn-
onymously, AF_LOCAL). (Most implementations have the same restric-
read(2), write(2), pipe(2), socket(2), unix(7)
BSD Man Page 1993-07-24 SOCKETPAIR(2)