man socketpair (2): create a pair of connected sockets

LIBRARY

Lb libc

SYNOPSIS

In sys/types.h In sys/socket.h Ft int Fn socketpair int fd int type int protocol int *sv

DESCRIPTION

The Fn socketpair system call creates an unnamed pair of connected sockets in the specified domain Fa fd , of the specified Fa type , and using the optionally specified Fa protocol . The descriptors used in referencing the new sockets are returned in Fa sv Ns [0] and Fa sv Ns [1] . The two sockets are indistinguishable.

The SOCK_CLOEXEC and SOCK_NONBLOCK flags in the Fa type argument apply to both descriptors.

RETURN VALUES

Rv -std socketpair

ERRORS

The call succeeds unless:

Bq Er EMFILE: Too many descriptors are in use by this process.
Bq Er EAFNOSUPPORT: The specified address family is not supported on this machine.
Bq Er EPROTONOSUPPORT: The specified protocol is not supported on this machine.
Bq Er EOPNOTSUPP: The specified protocol does not support creation of socket pairs.
Bq Er EFAULT: The address Fa sv does not specify a valid part of the process address space.

HISTORY

The Fn socketpair system call appeared in BSD 4.2

BUGS

This call is currently implemented only for the UNIX domain.