socketpair(2) [suse man page]

SOCKETPAIR(2)						     Linux Programmer's Manual						     SOCKETPAIR(2)

NAME

       socketpair - create a pair of connected sockets

SYNOPSIS

       #include <sys/types.h>	       /* See NOTES */
       #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 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, 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 synonymously, AF_LOCAL).  (Most implementations have the same restric-
       tion.)

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

       POSIX.1-2001 does not require the inclusion of <sys/types.h>, 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), socket(7), unix(7)

COLOPHON

       This  page is part of release 3.25 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								    2008-10-11							     SOCKETPAIR(2)

socketpair(2)							System Calls Manual						     socketpair(2)

NAME

       socketpair - Creates a pair of connected sockets

SYNOPSIS

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

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       socketpair():  XNS5.0

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

PARAMETERS

       Specifies the communications domain in which the sockets are created. This function does not create sockets in the Internet domain.  Speci-
       fies the communications method that sockets use, for example SOCK_DGRAM or SOCK_STREAM.	Specifies an optional identifier  used	to  define
       the communications protocols used in the transport layer interface.  Specifies a two-integer array used to hold the file descriptors of the
       socket pair created with the call to this function.

DESCRIPTION

       The socketpair() function creates an unnamed pair of connected sockets in a specified domain, of  a  specified  type,  under  the  protocol
       optionally  specified by the protocol parameter.  The two sockets are identical. The file descriptors used in referencing the created sock-
       ets are returned to socket_vector[0] and socket_vector[1]. The sys/socket.h include file contains definitions for  socket  domains,  types,
       and protocols.

       Not all protocol families support the socketpair() function.

RETURN VALUES

       Upon  successful  completion,  this function returns a value of 0 (zero).  Otherwise, -1 is returned and errno is specified to indicate the
       error.

ERRORS

       If the socketpair() function fails, errno may be set to one of the following values: The process have not have appropriate privileges.  The
       addresses  in the specified address family cannot be used to create this socket pair.  [Tru64 UNIX]  The socket_vector array is not located
       in a writable part of user address space.  The current process has too many open file descriptors.  No more file descriptors are  available
       for the system.	Insufficient resources were available in the system to complete the call.  The system was unable to allocate kernel memory
       to increase the process descriptor table.  The available STREAMS resources were insufficient for the operation to complete.  The  specified
       protocol does not permit creation of socket pairs.  The specified protocol cannot be used in this system.  The socket type is not supported
       by the protocol.

RELATED INFORMATION

       Functions: socket(2)

       Standards: standards(5) delim off

																     socketpair(2)