One man's voice Thoughts, rants and commentary of a simple man

< ?php
/**
 * User_Agent_Detector is used to gather information about the users browser
 * and operating system.
 *
 * This is not a flashy whiz-bang kind of class, but it works fairly well
 * if all you need is to fetch is the users browser and operating system.
 *
 * Usage:
 * <code>
 * The easiest way to use the class is to instantiate it:
 *      $uad = new User_Agent_Detector();
 * This will echo out a single line of text along the lines of:
 *         Browser: Mozilla Firefox 2.0.0 Operating System: Windows XP
 * To prevent the echo, pass a boolean false to the constructor
 *      $uad = new User_Agent_Detector(false);
 *
 * The class can also be instantiated and the browser and os fetched with:
 *      $browser = $uad->get_browser();
 *      $os = $uad->get_os();
 *
 * The browser and os can also be displayed by calling display()
 *      $uad->display('<p>', '</p>', '<br />');
 * The display() method takes three params: opentag, closetag, separator
 * 
 * @version 0.1
 * @package User_Agent_Detector
 * @copyright None
 * @license Creative Commons Attribution License 3.0 {@link http://creativecommons.org/licenses/by/3.0/}
 * @author Robert Gonzalez < robert@everah.com >
 * @author Dragan Dinic < dragan@dinke.net >
 */
class User_Agent_Detector
{
    /**
     * The users browser
     *
     * @var string
     * @access public
     */
    public $browser;
 
    /**
     * The users operating system
     *
     * @var string
     * @access public
     */
    public $os;
 
    /**
     * The users complete user agent identifier
     *
     * @var string
     * @access private
     */
    private $useragent;
 
    /**
     * Class constructor
     *
     * @author Robert Gonzalez < robert@everah.com >
     * @access public
     * @param boolean $echo True displays on construction
     */
    public function __construct($echo = true)
    {
        // Set the user agent
        $this->useragent = $this->set_useragent();
 
        // Set the rest of the vars
        $this->initialize();
 
        // Should we display immediately?
        if ($echo)
        {
            // If we were able to get the useragent render it
            if ($this->useragent !== false)
            {
                $this->display();
            }
            else // Otherwise puke
            {
                $this->error();
            }
        }
    }
 
    /**
     * Initialze all two of the class properties
     *
     * @author Robert Gonzalez < robert@everah.com >
     * @access private
     */
    private function initialize()
    {
        $this->set_browser();
        $this->set_os();
    }
 
    /**
     * Output what we know in a clean little outputter
     *
     * @author Robert Gonzalez < robert@everah.com >
     * @access public
     * @param string $opentag The HTML tag to use to open the string
     * @param string $closetag The HTML tag to use to close the string
     * @param string $separator The HTML tag to use to separate the browser from OS in the string
     * @return string A string displaying the users browser and OS
     */
    public function display($opentag = '', $closetag = '', $separator = ' ')
    {
        echo $opentag . 'Browser: ' . $this->browser . $separator . 'Operating System: ' . $this->os . $closetag;
    }
 
    /**
     * Output a generic error message
     *
     * @access private
     * @author Robert Gonzalez < robert@everah.com >
     * @return string A generic error message
     * @todo Maybe allow for custom error messaging - shouldn't be that hard to implement
     */
    private function error()
    {
        echo 'We were unable to detect your browser and operating system';
    }
 
    /**
     * Gets the users browser information
     *
     * @author Robert Gonzalez < robert@everah.com >
     * @access public
     * @return string The users browser
     */
    public function get_browser()
    {
        return $this->browser;
    }
 
    /**
     * Gets the users operating system
     *
     * @author Robert Gonzalez < robert@everah.com >
     * @access public
     * @return string The users operating system
     */
    public function get_os()
    {
        return $this->os;
    }
 
    /**
     * Sets the users complete user agent string
     *
     * @author Robert Gonzalez < robert@everah.com >
     * @access private
     * @return string The users user agent on success, boolean false on failure
     */
    private function set_useragent()
    {
        $useragent = null;
 
        if (isset($_SERVER['HTTP_USER_AGENT']))
        {
            $useragent = $_SERVER['HTTP_USER_AGENT'];
        }
        else
        {
            $useragent = getenv('HTTP_USER_AGENT');
        }
 
        return !is_null($useragent) ? $useragent : false;
    }
 
    /**
     * Get browsername and version
     *
     * @author Robert Gonzalez < robert@everah.com >
     * @access public
     */
    private function set_browser()
    {
        $this->browser = $this->get_browser_name();
    }
 
    /**
     * Get browsername and version
     *
     * @author Dragan Dinic < dragan@dinke.net >
     * @access private
     * @return string browser name and version or false if unrecognized
     */
    private function get_browser_name()
    {
        $useragent = $this->useragent;
 
        //check for most popular browsers first
        //unfortunately that's ie. We also ignore opera and netscape 8
        //because they sometimes send msie agent
        if (strpos($useragent, 'MSIE') !== false && strpos($useragent, 'Opera') === false && strpos($useragent, 'Netscape') === false)
        {
            //deal with IE
            if (preg_match('/MSIE ([0-9]{1}\.[0-9]{1,2})/', $useragent, $matches))
            {
                return 'Internet Explorer ' . $matches[1];
            }
        }
        elseif (strpos($useragent, 'Gecko'))
        {
            //deal with Gecko based
 
            //if firefox
            if (preg_match('/Firefox\/([0-9]{1}\.[0-9]{1}(\.[0-9])?)/', $useragent, $matches))
            {
                return 'Mozilla Firefox ' . $matches[1];
            }
 
            //if Netscape (based on gecko)
            if (preg_match('/Netscape\/([0-9]{1}\.[0-9]{1}(\.[0-9])?)/', $useragent, $matches))
            {
                return 'Netscape ' . $matches[1];
            }
 
            //if Safari (based on gecko)
            if (preg_match('/Safari\/([0-9]{2,3}(\.[0-9])?)/', $useragent, $matches))
            {
                return 'Safari ' . $matches[1];
            }
 
            //if Galeon (based on gecko)
            if (preg_match('/Galeon\/([0-9]{1}\.[0-9]{1}(\.[0-9])?)/', $useragent, $matches))
            {
                return 'Galeon ' . $matches[1];
            }
 
            //if Konqueror (based on gecko)
            if (preg_match('/Konqueror\/([0-9]{1}\.[0-9]{1}(\.[0-9])?)/', $useragent, $matches))
            {
                return 'Konqueror ' . $matches[1];
            }       
 
            //no specific Gecko found
            //return generic Gecko
            return 'Gecko based';                   
        }
        elseif (strpos($useragent, 'Opera') !== false)
        {
            //deal with Opera
            if (preg_match('/Opera[\/ ]([0-9]{1}\.[0-9]{1}([0-9])?)/', $useragent, $matches))
            {
                return 'Opera ' . $matches[1];
            }
        }
        elseif (strpos($useragent, 'Lynx') !== false)
        {
            //deal with Lynx           
            if (preg_match('/Lynx\/([0-9]{1}\.[0-9]{1}(\.[0-9])?)/', $useragent, $matches))
            {
                return 'Lynx ' . $matches[1];
            }
        }
        elseif (strpos($useragent, 'Netscape') !== false)
        {
            //NN8 with IE string
            if (preg_match('/Netscape\/([0-9]{1}\.[0-9]{1}(\.[0-9])?)/', $useragent, $matches))
            {
                return 'Netscape ' . $matches[1];
            }
        }
        else
        {
            //unrecognized, this should be less than 1% of browsers (not counting bots like google etc)!
            return false;
        }
    }
 
    /**
     * Sets the OS property
     *
     * @author Robert Gonzalez < robert@everah.com >
     * @access private
     */
    private function set_os()
    {
        $this->os = $this->get_os_name();
    }
 
    /**
     * Get browsername and version
     *
     * @author Dragan Dinic < dragan@dinke.net >
     * @access private
     * @param string user agent   
     * @return string os name and version or false in unrecognized os
     */
    private function get_os_name()
    {       
        $useragent = strtolower($this->useragent);
 
        //check for (aaargh) most popular first       
        //winxp
        if (strpos($useragent, 'windows nt 5.1') !== false)
        {
            return 'Windows XP';           
        }
        elseif (strpos($useragent, 'windows 98') !== false)
        {
            return 'Windows 98';
        }
        elseif (strpos($useragent, 'windows nt 5.0') !== false)
        {
            return 'Windows 2000';
        }
        elseif (strpos($useragent, 'windows nt 5.2') !== false)
        {
            return 'Windows 2003 server';
        }
        elseif (strpos($useragent, 'windows nt 6.0') !== false)
        {
            return 'Windows Vista';
        }
        elseif (strpos($useragent, 'windows nt') !== false)
        {
            return 'Windows NT';
        }
        elseif (strpos($useragent, 'win 9x 4.90') !== false && strpos($useragent, 'win me'))
        {
            return 'Windows ME';
        }
        elseif (strpos($useragent, 'win ce') !== false)
        {
            return 'Windows CE';
        }
        elseif (strpos($useragent, 'win 9x 4.90') !== false)
        {
            return 'Windows ME';
        }
        elseif (strpos($useragent, 'mac os x') !== false)
        {
            return 'Mac OS X';
        }
        elseif (strpos($useragent, 'macintosh') !== false)
        {
            return 'Macintosh';
        }
        elseif (strpos($useragent, 'linux') !== false)
        {
            return 'Linux';
        }
        elseif (strpos($useragent, 'freebsd') !== false)
        {
            return 'Free BSD';
        }
        elseif (strpos($useragent, 'symbian') !== false)
        {
            return 'Symbian';
        }
        else
        {
            return false;
        }
    }
}
 
$stats = new User_Agent_Detector(false);
echo $stats->browser . ' Is the browser as discovered by the class.<br />';
echo $stats->os . ' Is the os as discovered by the class.<br /><br />';
$stats->display('<p>', '</p>', '<br />');
?>