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 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.

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.

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.

HISTORY
The socketpair function call appeared in BSD 4.2.

BUGS
This call is currently implemented only for the UNIX domain. [Documenter's note: is this true for Linux?]

SEE ALSO
read(2), write(2), pipe(2)