(PHP 5 >= 5.1.0, PHP 7, PHP 8)
stream_socket_pair — Creates a pair of connected, indistinguishable socket streams
stream_socket_pair() creates a pair of connected, indistinguishable socket streams. This function is commonly used in IPC (Inter-Process Communication).
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.
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