SOCKETPAIR(3XNET)SOCKETPAIR(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_vector[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, connec‐
tion-mode byte streams, and may provide a transmis‐
sion 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, connec‐
tion-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 transfers 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 socket‐
pair() to use an unspecified default protocol appro‐
priate 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 specified
address family.
EMFILE
No more file descriptors are available for this
process.
ENFILE
No more file descriptors are available for the sys‐
tem.
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 implementa‐
tion.
EPROTOTYPE
The socket type is not supported by the protocol.
The socketpair() function may fail if:
EACCES
The process does not have appropriate privileges.
ENOBUFS
Insufficient resources were available in the system to per‐
form 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)
Jun 10, 2002 SOCKETPAIR(3XNET)
