NAME

       socketpair - create a pair of connected sockets

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <sys/socket.h>

       int socketpair(int domain, int type, int protocol, int sv[2]);

DESCRIPTION

       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.

RETURN VALUE

       On  success,  zero  is returned.  On error, -1 is returned, errno is set to indicate the error, and sv is
       left unchanged

       On Linux (and other systems), socketpair() does not modify sv on failure.   A  requirement  standardizing
       this behavior was added in POSIX.1-2008 TC2.

ERRORS

       EAFNOSUPPORT
              The specified address family is not supported on this machine.

       EFAULT The address sv does not specify a valid part of the process address space.

       EMFILE The per-process limit on the number of open file descriptors has been reached.

       ENFILE The system-wide limit on the total number of open files has been reached.

       EOPNOTSUPP
              The specified protocol does not support creation of socket pairs.

       EPROTONOSUPPORT
              The specified protocol is not supported on this machine.

VERSIONS

       On  Linux,  the  only supported domains for this call are AF_UNIX (or synonymously, AF_LOCAL) and AF_TIPC
       (since Linux 4.12).

STANDARDS

       POSIX.1-2008.

HISTORY

       POSIX.1-2001, 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).

       Since  Linux 2.6.27, socketpair() supports the SOCK_NONBLOCK and SOCK_CLOEXEC flags in the type argument,
       as described in socket(2).

SEE ALSO

       pipe(2), read(2), socket(2), write(2), socket(7), unix(7)

Linux man-pages 6.7                                2023-10-31                                      socketpair(2)