SOCKETPAIR(2)               BSD System Calls Manual              SOCKETPAIR(2)

NAME
     socketpair -- create a pair of connected sockets

SYNOPSIS
     #include <sys/socket.h>

     int
     socketpair(int domain, int type, int protocol, int socket_vector[2]);

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

RETURN VALUES
     The socketpair() function returns the value 0 if successful; otherwise
     the value -1 is returned and the global variable errno is set to indicate
     the error.

ERRORS
     The call succeeds unless:

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

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

     [EMFILE]           No more file descriptors are available for this
                        process.

     [ENFILE]           No more file descriptors are available for the system.

     [ENOBUFS]          Insufficient resources were available in the system to
                        perform the operation.

     [ENOMEM]           Insufficient memory was available to fulfill the
                        request.

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

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

     [EPROTOTYPE]       The socket type is not supported by the protocol.

     [EACCES]           The process does not have appropriate privileges to
                        create a socket of the specified type and/or protocol.

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

     The include file <sys/types.h> is necessary.

SEE ALSO
     socket(2), read(2), write(2), compat(5)

BUGS
     This call is currently implemented only for the UNIX domain.

HISTORY
     The socketpair() function call appeared in 4.2BSD.

4.2 Berkeley Distribution        June 4, 1993        4.2 Berkeley Distribution