socketpair(3XNET)X/Open Networking Services Library Functionssocketpair(3XNET)NAMEsocketpair - create a pair of connected sockets
SYNOPSIS
cc [ flag ... ] file ... -lxnet [ library ... ]
#include <sys/socket.h>
int socketpair(int domain, int type, int protocol, int socket_vec‐
tor[2]);
DESCRIPTION
The socketpair() function creates an unbound pair of connected sockets
in a specified domain, of a specified type, under the protocol option‐
ally specified by the protocol argument. The two sockets are identi‐
cal.
The file descriptors used in referencing the created sockets are
returned in socket_vector0 and socket_vector1.
The type argument specifies the socket type, which determines the
semantics of communications over the socket. The socket types sup‐
ported by the system are implementation-dependent. Possible socket
types include:
SOCK_STREAM Provides sequenced, reliable, bidirectional,
connection-mode byte streams, and may provide a
transmission mechanism for out-of-band data.
SOCK_DGRAM Provides datagrams, which are connectionless-
mode, unreliable messages of fixed maximum
length.
SOCK_SEQPACKET Provides sequenced, reliable, bidirectional,
connection-mode transmission path for records.
A record can be sent using one or more output
operations and received using one or more input
operations, but a single operation never trans‐
fers part of more than one record. Record
boundaries are visible to the receiver via the
MSG_EOR flag.
If the protocol argument is non-zero, it must specify a protocol that
is supported by the address family. The protocols supported by the
system are implementation-dependent.
The process may need to have appropriate privileges to use the socket‐
pair() function or to create some sockets.
PARAMETERS
domain Specifies the communications domain in which the sock‐
ets are to be created.
type Specifies the type of sockets to be created.
protocol Specifies a particular protocol to be used with the
sockets. Specifying a protocol of 0 causes socketpair()
to use an unspecified default protocol appropriate for
the requested socket type.
socket_vector Specifies a 2-integer array to hold the file descrip‐
tors of the created socket pair.
USAGE
The documentation for specific address families specifies which proto‐
cols each address family supports. The documentation for specific pro‐
tocols specifies which socket types each protocol supports.
The socketpair() function is used primarily with UNIX domain sockets
and need not be supported for other domains.
RETURN VALUES
Upon successful completion, this function returns 0. Otherwise, −1 is
returned and errno is set to indicate the error.
ERRORS
The socketpair() function will fail if:
EAFNOSUPPORT The implementation does not support the speci‐
fied address family.
EMFILE No more file descriptors are available for this
process.
ENFILE No more file descriptors are available for the
system.
EOPNOTSUPP The specified protocol does not permit creation
of socket pairs.
EPROTONOSUPPORT The protocol is not supported by the address
family, or the protocol is not supported by the
implementation.
EPROTOTYPE The socket type is not supported by the proto‐
col.
The socketpair() function may fail if:
EACCES The process does not have appropriate privi‐
leges.
ENOBUFS Insufficient resources were available in the
system to perform the operation.
ENOMEM Insufficient memory was available to fulfill
the request.
ENOSR There were insufficient STREAMS resources
available for the operation to complete.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Standard │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │MT-Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOsocket(3XNET), attributes(5), standards(5)SunOS 5.10 10 Jun 2002 socketpair(3XNET)
