PHP自动Get监控网站是否在线，创建个PHP文件放到你的网站根目录里面，访问后不会出现结果，等待个20秒左右关闭页面，就会自动执行了。
如果不重启php服务器 或者重启服务器，get监控一直会处于运行状态。
<?php
//设置脚本运行不超时
set_time_limit(0);
//即使浏览器关闭还继续运营
ignore_user_abort(true);
//睡眠5秒
sleep(5);
//要监控的网址
$cronurl = 'https://www.baidu.com/';
//开始get监控
httpGet($cronurl);
//这里还可以无限添加httpGet("网址");
//获取当前文件的访问url
$url="http://".$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
//开始get运行，达到无限循环的效果
httpGet($url);
//发起GET模拟请求
function httpGet($url) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_HTTPHEADER,array('Accept-Encoding: gzip, deflate'));
curl_setopt($ch, CURLOPT_ENCODING, 'gzip,deflate');
curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (iPhone; CPU iPhone OS 8_0 like Mac OS X) AppleWebKit/600.1.3 (KHTML, like Gecko) Version/8.0 Mobile/12A4345d Safari/600.1.4");
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 3);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
$output = curl_exec($ch);
curl_close($ch);
return $output;
}