异步请求URL-PHP

###异步GET请求函数
```php
<?
echo date('Y-m-d H:i:s');
echo "<hr>";
syncRequest('https://www.666.cn/2.php?a=111');
syncRequest('https://www.666.cn/2.php?a=222');
syncRequest('https://www.666.cn/2.php?a=333');
syncRequest('https://www.666.cn/2.php?a=444');
syncRequest('https://www.666.cn/2.php?a=555');
echo date('Y-m-d H:i:s');

function syncRequest($url,$timeout =10)
{
        $urlParmas = parse_url($url);

$host = $urlParmas['host'];
        $path = $urlParmas['path'].'?a='.rand(100,999);
        $port = isset($urlParmas['port'])? $urlParmas['port'] :80;
        $errno = 0;
        $errstr = '';

$fp = fsockopen($host, $port, $errno, $errstr, $timeout);

$out = "GET ".$path." HTTP/1.1\r\n";
        $out .= "host:".$host."\r\n";
        $out .= "content-type:application/x-www-form-urlencoded\r\n";
        $out .= "connection:close\r\n\r\n";
        echo $out."<hr>";
        fputs($fp, $out);
        fclose($fp);
}
```

###后端demo
```php
$t=$_GET['a']??'0';
sleep(5);
file_put_contents('2_log.txt',"$t--".date('Y-m-d H:i:s')."\r\n",FILE_APPEND);
echo $t;
```