socketpair — create a pair of connected sockets
#include <sys/types.h> /* See NOTES */ #include <sys/socket.h>
int
socketpair( |
int domain, |
| int type, | |
| int protocol, | |
int sv[2]); |
The socketpair() call
creates an unnamed pair of connected sockets in the specified
domain, of the
specified type, and
using the optionally specified protocol. For further details
of these arguments, see socket(2).
The file descriptors used in referencing the new sockets
are returned in sv[0]
and sv[1]. The two
sockets are indistinguishable.
On success, zero is returned. On error, −1 is
returned, and errno is set
appropriately.
On Linux (and other systems), socketpair() does not modify sv on failure. A requirement
standardizing this behavior was added in POSIX.1-2016.
The specified address family is not supported on this machine.
The address sv does not specify a
valid part of the process address space.
The per-process limit on the number of open file descriptors has been reached.
The system-wide limit on the total number of open files has been reached.
The specified protocol does not support creation of socket pairs.
The specified protocol is not supported on this machine.
POSIX.1-2001, POSIX.1-2008, 4.4BSD. socketpair() first appeared in 4.2BSD. It
is generally portable to/from non-BSD systems supporting
clones of the BSD socket layer (including System V
variants).
On Linux, the only supported domain for this call is
AF_UNIX (or synonymously,
AF_LOCAL). (Most
implementations have the same restriction.)
Since Linux 2.6.27, socketpair() supports the SOCK_NONBLOCK and SOCK_CLOEXEC flags in the type argument, as described in
socket(2).
POSIX.1 does not require the inclusion of <sys/types.h> and this header file is not required on
Linux. However, some historical (BSD) implementations
required this header file, and portable applications are
probably wise to include it.
This page is part of release 4.07 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
|
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