seo_test.php

<?php

$user_agents = array(
    'Mozilla/5.0 (X11; Fedora; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36',
    'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.0 Safari/605.1.15',
    'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36',
);
function get($index) {
    global $user_agents;
    $url = 'https://www.bing.com/search?q=site%3Amicrosoft.com&form=QBLH&sp=-1&pq=site%3Amicrosoft.com&sc=8-18&qs=n&sk=&cvid=195A4B0082114AFC9EEF2D7374C94B7D';
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    $userAgent = $user_agents[$index];
    curl_setopt($ch, CURLOPT_USERAGENT, $userAgent);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    $output = curl_exec($ch);
    curl_close($ch);
    return $output;
}

for ($i = 0; $i < count($user_agents) * 10; ++$i) {
    $output = get($i % count($user_agents));
    file_put_contents("/tmp/ua_" . $i . ".html", $output);
}