NAME

socketpair − Creates a pair of connected sockets

SYNOPSIS

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

PARAMETERS

domainSpecifies the communications domain in which the sockets are created. This function does not create sockets in the Internet domain. 

typeSpecifies the communications method that sockets use, for example SOCK_DGRAM or SOCK_STREAM. 

protocolSpecifies an optional identifier used to define the communications protocols used in the transport layer interface. 

socket_vectorSpecifies 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 sockets 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:

[EMFILE]The current process has too many open file descriptors. 

[EAFNOSUPPORT]
The addresses in the specified address family cannot be used to create this socket pair.

[EPROTONOSUPPORT]
The specified protocol cannot be used in this system.

[EOPNOTSUPP]
The specified protocol does not permit creation of socket pairs.

[EFAULT]The socket_vector array is not located in a writable part of user address space. 

[ENOMEM]The system was unable to allocate kernel memory to increase the process descriptor table. 

RELATED INFORMATION

Functions: socket(2)