stream_socket_pair

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

stream_socket_pair Creates a pair of connected, indistinguishable socket streams

Description

stream_socket_pair(int $domain, int $type, int $protocol): array|false

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