xyzshop/test/examples/client/udp_sync.php

<?php
$client = new swoole_client(SWOOLE_SOCK_UDP, SWOOLE_SOCK_SYNC);
$client->connect('127.0.0.1', 9502);

for ($i = 0; $i < 100; $i++)
{
    $client->send("admin");
    echo $client->recv()."\n";
    sleep(1);
}