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SOCKETPAIR(2) NetBSD System Calls Manual SOCKETPAIR(2)
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by Kimmo Suominen.
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socketpair -- create a pair of connected sockets
Standard C Library (libc, -lc)
socketpair(int d, int type, int protocol, int *sv);
The socketpair() call creates an unnamed pair of connected sockets in the
specified domain d, of the specified type, and using the optionally spec-
ified protocol. The descriptors used in referencing the new sockets are
returned in sv and sv. The two sockets are indistinguishable.
Possible values for the type argument are SOCK_STREAM, SOCK_DGRAM, and
SOCK_SEQPACKET; the only supported value for the protocol is 0, which
will let the system select an appropriate protocol for the requested
Any combination of the following flags may additionally be used in the
SOCK_CLOEXEC Set close-on-exec flag on both the new descriptors.
Set non-blocking I/O mode on both the new sockets.
Upon successful completion, the value 0 is returned; otherwise the
value -1 is returned and the global variable errno is set to indicate the
The call succeeds unless:
[EAFNOSUPPORT] The specified address family is not supported on this
[EFAULT] The address sv does not specify a valid part of the
process address space.
[EMFILE] Too many descriptors are in use by this process.
[ENFILE] The system file table is full.
[EOPNOTSUPP] The specified protocol does not support creation of
[EPROTONOSUPPORT] The specified protocol is not supported on this
pipe(2), read(2), socket(2), write(2)
The socketpair() function call appeared in 4.2BSD.
Support for the SOCK_CLOEXEC and SOCK_NONBLOCK flags appeared in
This call is currently implemented only for the PF_LOCAL domain.
NetBSD 10.99 November 29, 2022 NetBSD 10.99