| SOCKETPAIR(2) | System Calls Manual | SOCKETPAIR(2) | 
socketpair —
#include <sys/socket.h>
int
  
  socketpair(int
    d, int type,
    int protocol,
    int *sv);
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.
The type and protocol argument values are described in socket(2).
EAFNOSUPPORT]EFAULT]EMFILE]ENFILE]EOPNOTSUPP]EPROTONOSUPPORT]socketpair() function call appeared in
  4.2BSD.
PF_LOCAL
  domain.
| June 24, 2011 | NetBSD 9.4 |