Creates a pair of connected, indistinguishable socket streams

Description

array stream_socket_pair ( int $domain , int $type , int $protocol )

stream_socket_pair() creates a pair of connected, indistinguishable socket streams. This function is commonly used in IPC (Inter-Process Communication).

Parameters

domain: The protocol family to be used: STREAM_PF_INET, STREAM_PF_INET6 or STREAM_PF_UNIX
type: The type of communication to be used: STREAM_SOCK_DGRAM, STREAM_SOCK_RAW, STREAM_SOCK_RDM, STREAM_SOCK_SEQPACKET or STREAM_SOCK_STREAM
protocol: The protocol to be used: STREAM_IPPROTO_ICMP, STREAM_IPPROTO_IP, STREAM_IPPROTO_RAW, STREAM_IPPROTO_TCP or STREAM_IPPROTO_UDP

Note: Please consult the Streams constant list for further details on each constant.

Return Values

Returns an array with the two socket resources on success, or FALSE on failure.

Changelog

Version	Description
5.3.0	This function is now available on Windows platforms.

Examples

Example #1 A stream_socket_pair() example

This example shows the basic usage of stream_socket_pair() in Inter-Process Comunication.


<?php

$sockets = stream_socket_pair(STREAM_PF_UNIX, STREAM_SOCK_STREAM, STREAM_IPPROTO_IP);
$pid     = pcntl_fork();

if ($pid == -1) {
     die('could not fork');

} else if ($pid) {
     /* parent */
    fclose($sockets[0]);

    fwrite($sockets[1], "child PID: $pid\n");
    echo fgets($sockets[1]);

    fclose($sockets[1]);

} else {
    /* child */
    fclose($sockets[1]);

    fwrite($sockets[0], "message from child\n");
    echo fgets($sockets[0]);

    fclose($sockets[0]);
}

?>

The above example will output something similar to:

child PID: 1378
message from child