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 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 domain is a protocol family, such as AF_UNIX (see unix(7)), the type is a type of socket, such as SOCK_STREAM, SOCK_SEQPACKET or SOCK_DGRAM.

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.

ENFILE

Not enough file descriptors available system wide.

EAFNOSUPPORT

The specified address family is not supported on this machine.

EPROTONOSUPPORT

The specified protocol is not supported on this machine.

EOPNOSUPPORT?

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.

ENOMEM

Insufficient memory was available to fulfill the request.

ENOBUFS

Insufficient resources were available in the system to perform the operation.

EACCES

Permission denied (Documented by POSIX)

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).

SEE ALSO

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