Question

I need to display additional information on a web page (PHP) if one of the following criteria is met:

• .NET Framework Installed on the client machine in lower than 3.5
• Impossible to determine if .NET Framework 3.5 is installed or not on the client machine

I know that some browser (if not only one, IE) is sending that information in his tag.

Can any of you provide me with his suggestions ?

Website is built in PHP.

Thanks!

EDIT:

Proposed answers are incomplete and/or don’t provide me with a robust solution.

Answer 1

Here is another version I actually made for a friend of mine and realised that there was a bounty on this thread so what the hell 🙂

This is fully working but only with User-agent strings as there is no alternative means of doing so.

The core class:

class NETFrameworkChecker
{
    //General String / Array holders
    var $original_au,$ua_succesParse,$ua_componants,$ua_dotNetString,$CLRTag = "";

    //IsInstalled
    var $installed = false;

    //Version holders
    public $major = 0,$minor = 0,$build = 0;

    public function __construct($ua = false)
    {
        $this->original_au = $ua !== false ? $ua : $_SERVER['HTTP_USER_AGENT'];
        $this->ParserUserAgent();
    }

    public function Installed(){return (bool)$this->installed;}

    public function AUTag(){return $this->CLRTag;}

    //Version Getters
    public function getMajor(){return $this->major;}
    public function getMinor(){return $this->minor;}
    public function getBuild(){return $this->build;}

    private function ParserUserAgent()
    {
        $this->ua_succesParse = (bool) preg_match('/(?<browser>.+?)\s\((?<components>.*?)\)/',$this->original_au,$this->ua_componants);
        if($this->ua_succesParse)
        {
            $this->ua_componants = explode(';',$this->ua_componants['components']);
            foreach($this->ua_componants as $aComponant)
            {
                $aComponant = trim($aComponant);
                if(substr(strtoupper($aComponant),0,4) == ".NET")
                {
                    //We have .Net Installed
                    $this->installed = true;
                    $this->CLRTag = $aComponant;

                    //Lets make sure we can get the versions
                    $gotVersions = (bool)preg_match("/\.NET.CLR.+?(?<major>[0-9]{1})\.(?<minor>[0-9]{1})\.(?<build>[0-9]+)/si",$aComponant,$versions);
                    if($gotVersions)
                    {
                        $this->major = (int)$versions['major'];
                        $this->minor = (int)$versions['minor'];
                        $this->build = (int)$versions['build'];
                    }
                    break;
                }
            }
        }
    }
}

Example Usage:

$Net = new NETFrameworkChecker(); //leave first param blank to detect current user agent

if($Net->Installed())
{
   if($Net->getMajor()> 2 && $Net->getMinor() >= 0)
   {
      //User is using a >NET system thats greater than 2.0.0000
      if($Net->GetBuild() >= 0200)
      {
         //We can do stuff with so that's only supported from this build up-words
      }
   }else
   {
      //Redirect them asking them to upgrade :) pretty please
   }
}

If you also want to check custom UA Strings from DB lets say

$Net = new NETFrameworkChecker("Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; Pivim Multibar; GTB6.4; .NET CLR 2.0.50727)");