socketpair(2) — Linux manual page

 socketpair(2)              System Calls Manual              socketpair(2) 

NAME         top

        socketpair - create a pair of connected sockets 

LIBRARY         top

        Standard C library (libc, -lc) 

SYNOPSIS         top

        #include <sys/socket.h>         int socketpair(int domain, int type, int protocol, int sv[2]); 

DESCRIPTION         top

        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         top

        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         top

        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         top

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

STANDARDS         top

        POSIX.1-2008. 

HISTORY         top

        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         top

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

COLOPHON         top

        This page is part of the man-pages (Linux kernel and C library        user-space interface documentation) project.  Information about        the project can be found at         ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report        for this manual page, see        ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.        This page was obtained from the tarball man-pages-6.15.tar.gz        fetched from        ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on        2025-08-11.  If you discover any rendering problems in this HTML        version of the page, or you believe there is a better or more up-        to-date source for the page, or you have corrections or        improvements to the information in this COLOPHON (which is not        part of the original manual page), send a mail to        [email protected]  Linux man-pages 6.15            2025-05-17                  socketpair(2) 

Pages that refer to this page: pipe(2),  socket(2),  socketcall(2),  syscalls(2),  sockaddr(3type),  fifo(7),  pipe(7),  signal-safety(7),  socket(7),  unix(7)

HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH.