Check request per seconds on Nginx with PHP

nginxrps.php

<?php

while (true)
{

    $query_start = microtime(true);
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, "http://127.0.0.1/nginx_status");
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array(
        'Host: whatever-host-name',
    ));

    $rawData = curl_exec($curl);
    curl_close($curl);
    $query_time = microtime(true) - $query_start;

    if (preg_match('/(\d+)\s+(\d+)\s+(\d+)/', $rawData, $m))
    {
        $new_requests = $m[3] - 1;
        if ( isset( $requests ) )
        {
            echo "RPS: ", (($new_requests-$requests)/(3+$query_time)), "\n";
        }

        $requests = $new_requests;
    }

    usleep(3000000);
}