getClientInfo

function getClientInfo($user_agent = '') {

    if (!$user_agent) {
        $user_agent = $_SERVER['HTTP_USER_AGENT'];
    }

    $res = false;

    $browser_name = array(

        'Avant Browser'                 => 'avant',

        'Opera'                         => 'opera',
        'Opera Mini'                    => 'opera-mini',

        'Phoenix'                       => 'ff',
        'Firebird'                      => 'ff',
        'Firefox'                       => 'ff',
        'GranParadiso'                  => 'ff',
        'Shiretoko'                     => 'ff',

        'Netscape'                      => 'netscape',
        'Konqueror'                     => 'konqueror',

        'amaya'                         => 'amaya',
        'America Online Browser'        => 'aol',
        'Camino'                        => 'camino',
        'ELinks'                        => 'elinks',
        'Epiphany'                      => 'epiphany',
        'Flock'                         => 'flock',
        'Chrome'                        => 'chrome',
        'Iceweasel'                     => 'iceweasel',
        'IceCat'                        => 'icecat',
        'iCab'                          => 'icab',
        'K-Meleon'                      => 'k-meleon',
        'Links'                         => 'links',
        'Lynx'                          => 'lynx',
        'Minimo'                        => 'minimo',
        'OffByOne'                      => 'offbyone',
        'OmniWeb'                       => 'omniweb',
        'SeaMonkey'                     => 'seamonkey',
        'Shiira'                        => 'shiira',

        'Windows CE'                    => 'ie-mobile',
        'Microsoft Internet Explorer'   => 'ie',
        'MSIE'                          => 'ie',

        'Safari'                        => 'safari'
    );

    $browser_vers = array(

        'Microsoft Internet Explorer'   => '/Microsoft Internet Explorer[\/]([a-z0-9.+-]*)/i',
        'Phoenix'                       => '/Phoenix[\/]([a-z0-9.+-]*)/i',
        'Firebird'                      => '/Firebird[\/]([a-z0-9.+-]*)/i',
        'Firefox'                       => '/Firefox[\/]([a-z0-9.+-]*)/i',
        'GranParadiso'                  => '/GranParadiso[\/]([a-z0-9.+-]*)/i',
        'Shiretoko'                     => '/Shiretoko[\/]([a-z0-9.+-]*)/i',
        'Konqueror'                     => '/Konqueror[\/]([a-z0-9.+-]*)/i',
        'amaya'                         => '/Amaya[\/]([a-z0-9.+-]*)/i',
        'Camino'                        => '/Camino[\/]([a-z0-9.+-]*)/i',
        'Epiphany'                      => '/Epiphany[\/]([a-z0-9.+-]*)/i',
        'Flock'                         => '/Flock[\/]([a-z0-9.+-]*)/i',
        'Chrome'                        => '/Chrome[\/]([a-z0-9.+-]*)/i',
        'Iceweasel'                     => '/Iceweasel[\/]([a-z0-9.+-]*)/i',
        'IceCat'                        => '/IceCat[\/]([a-z0-9.+-]*)/i',
        'K-Meleon'                      => '/K-Meleon[\/]([a-z0-9.+-]*)/i',
        'Lynx'                          => '/Lynx[\/]([a-z0-9.+-]*)/i',
        'Minimo'                        => '/Minimo[\/]([a-z0-9.+-]*)/i',
        'OmniWeb'                       => '/OmniWeb[\/]([a-z0-9.+-]*)/i',
        'SeaMonkey'                     => '/SeaMonkey[\/]([a-z0-9.+-]*)/i',
        'Shiira'                        => '/Shiira[\/]([a-z0-9.+-]*)/i',
        'Safari'                        => '/Shiira[\/]([a-z0-9.+-]*)/i',

        'ELinks'                        => '/ELinks \(([a-z0-9.+-]*)[;]/i',
        'Links'                         => '/Links \(([a-z0-9.+-]*)[;]/i',

        'MSIE'                          => '/MSIE[\s]([0-9.+-]*)[;]/i',
        'America Online Browser'        => '/America Online Browser[\s]([a-z0-9.+-]*)/i',
        'iCab'                          => '/iCab[\s]([0-9.+-]*)[;]/i',

        'Opera'                         => '/Opera[\/\s]([a-z0-9.+-]*)/i',

        'Netscape'                      => '/Netscape[6]?[\/]([a-z0-9.+-]*)/i',

        'Windows CE'                    => '',
        'OffByOne'                      => '',
        'Avant Browser'                 => '',

        'Unknow'                    => ''
    );

    $os_name = array(

        'Windows'       => 'win',
        'Macintosh'     => 'mac',
        'Mac OS'        => 'mac',
        'Mac_PowerPC'   => 'mac',
        'Ubuntu'        => 'linux ubuntu',
        'Linux'         => 'linux',
        'SunOS'         => 'unix sunos',
        'FreeBSD'       => 'unix freebsd',
        'w3m'           => 'unix freebsd',

        'J2ME/MIDP'     => 'java',
        'iPhone'        => 'iphone',
        'iPad'      => 'ipad',
        'Symbian OS'    => 'symbian'
    );

    $os_vers = array(

        'Windows'       => '/Windows[\s]([a-z0-9.+-\s]*)[;)]/i',
        'Macintosh'     => '',
        'Mac OS'        => '',
        'Mac_PowerPC'   => '',
        'Ubuntu'        => '/Ubuntu[\/\s]([a-z0-9.+-\s]*)/i',
        'Linux'         => '',
        'SunOS'         => '',
        'FreeBSD'       => '',
        'w3m'           => '',

        'J2ME/MIDP'     => '',
        'iPhone'        => '',
        'Symbian OS'    => ''
    );

    // Сначало нужно узнать браузер!

    foreach ($browser_name as $key => $value) {
        $pos = strpos($user_agent, $key);
        if ($pos !== false) {
            $res['browser_key'] = $key;
            $res['browser_name'] = $value;
            break;
        }
    }

    if (!$res['browser_key']) {
        $res['browser_key'] = 'Unknow';
        $res['browser_name'] = 'Unknow';
    }

    $pattern = $browser_vers[$res['browser_key']];
    if ($pattern) {
        if (preg_match($pattern, $user_agent, $match)) {
            $res['browser_version'] = $match[1];
        } else {
            $res['browser_version'] = '';
        }
    } else {
        $res['browser_version'] = '';
    }

    // Теперь ОСЬ

    foreach ($os_name as $key => $value) {
        $pos = strpos($user_agent, $key);
        if ($pos !== false) {
            $res['os_key'] = $key;
            $res['os_name'] = $value;
            break;
        }
    }

    if (!$res['os_key']) {
        $res['os_key'] = 'Unknow';
        $res['os_name'] = 'Unknow';
    }

    $pattern = $os_vers[$res['os_key']];
    if ($pattern) {
        if (preg_match($pattern, $user_agent, $match)) {
            $res['os_version'] = $match[1];

            if ($res['os_key'] == 'Windows') {
                switch ($res['os_version']) {
                    case 'NT 5.0': $res['os_version'] = '2000'; break;
                    case 'NT 5.1': $res['os_version'] = 'xp'; break;
                    case 'NT 5.2': $res['os_version'] = 'xp64'; break;
                    case 'NT 6.0': $res['os_version'] = 'vista'; break;
                    case 'NT 6.1': $res['os_version'] = '7'; break;
                    case 'NT 2000': $res['os_version'] = '2000'; break;
                }
            }
        } else {
            $res['os_version'] = '';
        }
    } else {
        $res['os_version'] = '';
    }

    if (isset($res['os_key']))      unset($res['os_key']);
    if (isset($res['browser_key'])) unset($res['browser_key']);

    $res['os'] = $res['os_name'].$res['os_version'];
    $res['browser'] = $res['browser_name'].$res['browser_version'];

    return $res;
}