PHP Manual: Creates a pair of connected, indistinguishable socket streams

Description

arrayfalse 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.

Examples

Example #1 A stream_socket_pair example

This example shows the basic usage of stream_socket_pair in Inter-Process Communication.

<?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