Check browser problem...

[Anon]

I have a script that I include on all pages om my site to check if the users are running a browser supported by the site.

The browsercheck part of the code looks like this:
$browser = "bad";
if (eregi("msie 5", $HTTP_USER_AGENT)) {
$browser = "ok";
} elseif (eregi("msie 6", $HTTP_USER_AGENT)) {
$browser = "ok";
}
if (eregi("netscape6", $HTTP_USER_AGENT)) {
$browser = "ok";
}
if (eregi("mozilla/5", $HTTP_USER_AGENT)) {
$browser = "ok";
}
if (eregi("opera", $HTTP_USER_AGENT)) {
$browser = "bad";
}

The problem is that search-engine spiders and various web-scripts will be classified as "bad" with this method causing a sub-optimal indexing of my site.

I am considering making the default value "ok" and then checking for the browsers that I know DON'T work. But that's a looong list if I have to include all old browserversions.

Is there another way to make sure that the search engine bots arenot caught in this check?

Thanks,

// Mads

[blizzard]

This is a unit taht handles MSIE, NS, Mozilla, Opera, Konqueror and Lynx. You can check for major version, minor version of the agent and more ... good luck

blizzard

<?php

/***************************************
Authors : epsilon7 and blizzard
Emails : [e-mail]
[e-mail]
Created : May 11, 2000
Last Modified : August 12, 2002
** Modified By : blizzard
'
INFO:
Returns Browser information
based on HTTP_USER_AGENT

Usage:
include("browserdetector.php");
$bd = new BrowserDetector;
'****************************************/
class BrowserDetector
{
var $UA = "";
var $BROWSER = "Unknown";
var $PLATFORM = "Unknown";
var $VERSION = "";
var $MAJORVER = "";
var $MINORVER = "";

/ START CONSTRUCTOR /
function BrowserDetector($user_agent="")
{
$this->UA = $user_agent!="" ? $user_agent : getenv(HTTP_USER_AGENT);
$this->detect();
}
function detect($user_agent="")
{
$this->UA = $user_agent!="" ? $user_agent : $this->UA;
$this->BROWSER="Unknown";
$this->PLATFORM="Unknown";
$this->VERSION="";
$this->MAJORVER="";
$this->MINORVER="";

$preparens = "";
$parens = "";
$postparens ="";
$i = strpos($this->UA,"(");
if ($i === false)
{
  $preparens = $this->UA;
}
else
{
  $preparens = trim(substr($this->UA,0,$i));
  $parens = substr($this->UA,$i+1,strlen($this->UA));
  $j = strpos($parens,")");
  if($j>=0)
  {
    $postparens = substr($parens,$j+1,strlen($parens));
    $parens = substr($parens,0,$j);
  }
}
$browVer = $preparens;
$token = trim(strtok($parens,";"));
while($token)
{
  if($token=="compatible")
  {
  }
  else if(preg_match("/MSIE/i","$token"))
  {
    $browVer = $token;
  }
  else if(preg_match("/Konqueror/i","$token"))
  {
    $browVer = $token;
  }
  else if(preg_match("/Opera/i","$token"))
  {
    $browVer = $token;
  }
  else if(preg_match("/X11/i","$token") || preg_match("/SunOS/i","$token") || preg_match ("/Linux/i","$token"))
  {
    $this->PLATFORM = "Unix";
  }
  else if(preg_match("/Win/i","$token"))
  {
    $token = trim($token);
    if($token=="Windows NT 5.0")
      $token="Windows 2000";
    else if($token=="Windows NT 5.1")
      $token="Windows XP";
    $this->PLATFORM = $token;
  }
  else if(preg_match("/Mac/i","$token") || preg_match("/PPC/i","$token"))
  {
    $this->PLATFORM = trim($token);
  }
  $token = strtok(";");
}//while
$msieIndex = strpos($browVer,"MSIE");
if($msieIndex >= 0)
{
  $browVer = substr($browVer,$msieIndex,strlen($browVer));
}
$leftover = "";
$browVer=trim($browVer);
if(substr($browVer,0,strlen("Mozilla")) == "Mozilla")
{
  $this->BROWSER = "Netscape";
  $leftover=substr($browVer,strlen("Mozilla")+1,strlen($browVer));
}
else if(substr($browVer,0,strlen("Lynx")) == "Lynx")
{
  $this->BROWSER = "Lynx";
  $leftover=substr($browVer,strlen("Lynx")+1,strlen($browVer));
}
else if(substr($browVer,0,strlen("MSIE")) == "MSIE")
{
  $this->BROWSER = "IE";
  $leftover=substr($browVer,strlen("MSIE")+1,strlen($browVer));
}
else if(substr($browVer,0,strlen("Microsoft Internet Explorer")) == "Microsoft Internet Explorer")
{
  $this->BROWSER = "IE";
  $leftover=substr($browVer,strlen("Microsoft Internet Explorer")+1,strlen($browVer));
}
else if(substr($browVer,0,strlen("Konqueror")) == "Konqueror")
{
  $this->BROWSER = "Konqueror";
  $leftover=substr($browVer,strlen("Konqueror")+1,strlen($browVer));
}
else if(substr($browVer,0,strlen("Opera")) == "Opera")
{
  $this->BROWSER = "Opera";
  $leftover=substr($browVer,strlen("Opera")+1,strlen($browVer));
}
$leftover = trim($leftover);
$i=strpos($leftover," ");
if($i > 0)
{
  $this->VERSION = substr($leftover,0,$i);
}
else
{
  $this->VERSION = $leftover;
}
$j = strpos($this->VERSION,".");
if($j >= 0)
{
  $this->MAJORVER = substr($this->VERSION,0,$j);
  $this->MINORVER = substr($this->VERSION,$j+1,strlen($this->VERSION));
}
else
{
  $this->MAJORVER = $this->VERSION;
}
/* Mozilla, Netscape6+, Opera advanced detection */
$token = strtok(trim($postparens)," ");
while($token)
{
  if(preg_match("/Gecko/i","$token"))
    $this->BROWSER = "Mozilla";
  else if(preg_match("/Netscape/i","$token"))
  {
    $this->BROWSER = "Netscape";
    $i = strpos($token,"/");
    $this->VERSION = substr($token, $i+1, strlen($token));
    $j = strpos($this->VERSION,".");
    if($j >= 0)
    {
      $this->MAJORVER = substr($this->VERSION,0,$j);
      $this->MINORVER = substr($this->VERSION,$j+1,strlen($this->VERSION));
    }
    else
    {
      $this->MAJORVER = $this->VERSION;
    }
  }
  else if(preg_match("/Opera/i","$token"))
  {
    $this->BROWSER = "Opera";
    $this->VERSION = strtok(" ");
    $j = strpos($this->VERSION,".");
    if($j >= 0)
    {
      $this->MAJORVER = substr($this->VERSION,0,$j);
      $this->MINORVER = substr($this->VERSION,$j+1,strlen($this->VERSION));
    }
    else
    {
      $this->MAJORVER = $this->VERSION;
    }
  }
  $token = strtok(" ");
}

}//detect
}//class
/****************************************
Some Test Results

Testing : Mozilla/4.73 [en] (Win98; U)
Browser : Netscape
Platform : Win98
Version : 4.73
Major Version : 4
Minor Version : 73

Testing : Opera/4.0 (Windows 98;US) Beta 3 [en]
Browser : Opera
Platform : Windows 98
Version : 4.0
Major Version : 4
Minor Version : 0

Testing : Mozilla/4.0 (compatible; MSIE 5.0; Windows 98; DigExt)
Browser : IE
Platform : Windows 98
Version : 5.0
Major Version : 5
Minor Version : 0

'****************************************/

?>

[Anon]

of course, that is just phpSniff which you can get the whole thing at http://phpsniff.sourceforge.org/

[Anon]

Thanks for your input. I decided on this hack instead which seems to do the trick in this particular case where I want all BROWSERS that are not NS6+, IS5+ or Mozilla 1 to turn out "bad" but want crawlers etc. to be able to access the site. I know this is not 100% waterproof but I think it holds up, no?

// Mads

// Assume browser is allright ;-)
$browser = "ok";
// First classify all mozilla browsers as bad!	
if (eregi("mozilla/1", $HTTP_USER_AGENT)) {
	$browser = "bad";
} elseif (eregi("mozilla/2", $HTTP_USER_AGENT)) {
	$browser = "bad";
} elseif (eregi("mozilla/3", $HTTP_USER_AGENT)) {
	$browser = "bad";
} elseif (eregi("mozilla/4", $HTTP_USER_AGENT)) {
	$browser = "bad";
}
// Then classify relevant browsers ok!
if (eregi("msie 5", $HTTP_USER_AGENT)) {
	$browser = "ok";
} elseif (eregi("msie 6", $HTTP_USER_AGENT)) {
	$browser = "ok";
}
if (eregi("netscape6", $HTTP_USER_AGENT)) {
	$browser = "ok";
}
if (eregi("mozilla/5", $HTTP_USER_AGENT)) {
	$browser = "ok";
}