PHP获取用户设备信息

/**
 * 获取用户设备信息
 */
function equipmentSystem() {
    $agent = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : '';
    if (stristr($agent, 'iPad')) {
        $fb_fs = "iPad";
    } else if (preg_match('/Android (([0-9_.]{1,3})+)/i', $agent, $version)) {
        $fb_fs = "手机(Android " . $version[1] . ")";
    } else if (stristr($agent, 'Linux')) {
        $fb_fs = "电脑(Linux)";
    } else if (preg_match('/iPhone OS (([0-9_.]{1,3})+)/i', $agent, $version)) {
        $fb_fs = "手机(iPhone " . $version[1] . ")";
    } else if (preg_match('/Mac OS X (([0-9_.]{1,5})+)/i', $agent, $version)) {
        $fb_fs = "电脑(OS X " . $version[1] . ")";
    } else if (preg_match('/unix/i', $agent)) {
        $fb_fs = "Unix";
    } else if (preg_match('/windows/i', $agent)) {
        $fb_fs = "电脑(Windows)";
    } else {
        $fb_fs = "Unknown";
    }
    return $fb_fs;
}