SOCKETPAIR(2)		   Linux Programmers Manual		SOCKETPAIR(2)



NAME
       socketpair - create a pair of connected sockets

SYNOPSIS
       #include 	       /* See NOTES */
       #include 

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

DESCRIPTION
       The  socketpair()  call creates an unnamed pair of connected sockets in
       the specified domain d, of the specified type, and using the optionally
       specified  protocol.  The descriptors used in referencing the new sock
       ets are returned in sv[0] and sv[1].  The  two  sockets	are  indistin
       guishable.

RETURN VALUE
       On  success,  zero is returned.	On error, -1 is returned, and errno is
       set appropriately.

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 Too many descriptors are in use by this process.

       ENFILE The  system  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.

CONFORMING TO
       4.4BSD,	POSIX.1-2001.	The  socketpair()  function  call  appeared in
       4.2BSD.	It is generally portable to/from  non-BSD  systems  supporting
       clones of the BSD socket layer (including System V variants).

NOTES
       On  Linux,  the only supported domain for this call is AF_UNIX (or syn
       onymously, AF_LOCAL).  (Most implementations  have  the	same  restric
       tion.)

       POSIX.1-2001  does not require the inclusion of , and this
       header file is not required on Linux.  However, some  historical  (BSD)
       implementations	required  this	header file, and portable applications
       are probably wise to include it.

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

COLOPHON
       This page is part of release 3.05 of the Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.



Linux				  2004-06-17			 SOCKETPAIR(2)