PHPでブラウザのバージョンを調べる

<?php
    header("Content-type: text/html;charset=utf-8");
    $agent = getenv( "HTTP_USER_AGENT" );
    $msg = "";
    $patterns = array('/MSIE [0-9]+\.[0-9]+/',
                      '/Firefox\/[0-9]+\.[0-9]+/',
                      '/OPR\/[0-9]+\.[0-9]+/',
                      '/Chrome\/[0-9]+\.[0-9]+/',
                      '/[0-9]+\.[0-9]+\.[0-9]+ Safari/');
    for($i=0, $len=count($patterns); $i<$len; $i++) {
        if (preg_match($patterns[$i], $agent, $matches, PREG_OFFSET_CAPTURE, 0)) {
            $msg = "お使いのブラウザは「" . $matches[0][0] . "」です。";
            break;
        }
    }
    echo $msg;
?>

ネタ元

• http://sookibizviz.blog81.fc2.com/blog-entry-1615.html