NAME
socketpair() — create a pair of connected sockets
SYNOPSIS
#include <sys/socket.h>
int socketpair(int af, int type, int protocol, int sv[2]);
DESCRIPTION
The
socketpair()
system call creates an unnamed pair of connected sockets
and returns two file descriptors in
sv[0]
and
sv[1].
The two sockets are indistinguishable.
af
specifies the address family.
See
socket(2).
type
specifies the semantics of communication for the socket.
protocol
specifies a particular protocol to be used.
protocol
can be specified as zero,
which causes the system to choose a protocol type to use.
RETURN VALUE
socketpair()
returns the following values:
- 0
Successful completion.
- -1
Failure.
errno
is set to indicate the error.
ERRORS
If
socketpair()
fails,
errno
is set to one of the following values.
- [EAFNOSUPPORT]
The specified address family
is not supported in this version of the system.
- [EFAULT]
The
sv
parameter is not valid.
- [EMFILE]
The per-process file descriptor table is full.
- [ENFILE]
The system file table is temporarily full.
- [ENOBUFS]
No buffer space is available for the operation to complete.
- [EOPNOTSUPP]
The specified protocol does not support creation of socket pairs.
- [EPROTONOSUPPORT]
The specified protocol is not supported in this version of the system.
DEPENDENCIES
socketpair()
is supported only for AF_UNIX.
FUTURE DIRECTION
Currently, the default behavior is the
HP-UX BSD Sockets;
however, it might be changed to
X/Open Sockets
in a future release.
At that time, any
HP-UX BSD Sockets
behavior that is incompatible with
X/Open Sockets
might be obsoleted.
Applications that conform to the
X/Open specification now
will avoid migration problems (see
xopen_networking(7))
MULTITHREAD USAGE
The
socketpair()
system call is thread-safe.
It has a cancellation point; and
it is async-cancel safe, async-signal safe, and fork-safe.
AUTHOR
socketpair()
was developed by HP and the University of California, Berkeley.
STANDARDS CONFORMANCE
socketpair(): XPG4
