Find unused port (cli - php)

unused_port.php

#!/usr/bin/php
<?php

$address = '127.0.0.1';

// Create a new socket
$sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);

// Bind the source address
socket_bind($sock, $address);

socket_getsockname($sock, $address, $port);

echo $port;

socket_close($sock);