S2OJ/web/app/controllers/judge/sync_judge_client.php

<?php
requirePHPLib('judger');
requirePHPLib('data');

if (!authenticateJudger()) {
	UOJResponse::page404();
}

$res = DB::selectAll([
	"select * from judger_info",
	"where", [
		["ip", "!=", ""],
		"enabled" => true
	]
]);
foreach ($res as $judger) {
	$socket = fsockopen($judger['ip'], UOJConfig::$data['judger']['socket']['port']);
	if ($socket === false) {
		die("judge client {$judger['ip']} lost.");
	}
	fwrite($socket, json_encode([
		'password' => UOJConfig::$data['judger']['socket']['password'],
		'cmd' => 'update'
	]));
	fclose($socket);
}

die("ok");