Browser Sniffing

[Chris Gwynne]

Hey

I have the following code which I've just started using on my site;

if(strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE')) { echo 'go and upgrade'; die(); } 

This detects Internet Explorer and shows the message, otherwise it shows the website. However I've just tested in Opera and it displays this message too when it should be showing the site.

I'm far from a PHP guru so I don't know what to change to only block out IE.

Any help?


Chris

[awasson]

Hey Chris,

I think that because msie shows first in the string returned you need to order your conditional accordingly.

This is Opera 7
mozilla/4.0 (compatible; msie 6.0; windows nt 5.1) opera 7.51 [en]

Here's a conditional that'll work for you. You could change it to a switch statement to make it a bit cleaner:

<?php  
$client = strtolower($_SERVER['HTTP_USER_AGENT']);
if(strpos($client, 'opera')) { echo 'It\'s Opera. You get the point'; die(); }
if(strpos($client, 'msie')) { echo 'It\'s IE. Go and upgrade'; die(); }
if(strpos($client, 'webtv')) { echo 'It\'s WebTV. Who would have thought?'; die(); }
if(strpos($client, 'gecko')) { echo 'It\'s Gecko. Good on ya!'; die(); }
if(strpos($client, 'safari')) { echo 'It\'s Safari. Must be OSX'; die(); }
if(strpos($client, 'konqueror')) { echo 'It\'s Konqueror. Odds are you\'re running Linux'; die(); }
?>

Cheers - Andrew

[mikis]

if(strpos($_SERVER['HTTP_USER_AGENT'], 'MSIE') && !strpos($_SERVER['HTTP_USER_AGENT'], 'Opera')) { echo 'go and upgrade'; die(); } 

[Chris Gwynne]

Haven't tried these out but by the looks of things they'd just show the message go and upgrade or whatever for each browser.

I want to only block out MSIE and allow every other browser to view the site....

[awasson]

I want to only block out MSIE and allow every other browser to view the site....

Wow... Like a reverse MSN thing

Ok really simple to do. You know how conditionals work right?

Well your code looks like it anyway. Take the one that mikis put up and then redirect the browser of the IE user away from your page to a page that tels them to upgrade. In my code sample we'll call it upgrade.php. Everyone else gets to vew the page.

$client = strtolower($_SERVER['HTTP_USER_AGENT']); 
if(strpos($client, 'msie') && !strpos($client, 'opera')) 
{ 
    //THIS IS AN EVIL MSIE BROWSER REDIRECT THEM
    header("Location:upgrade.php"); 
} 

How's that?

[Koobi]

If you have the browscap.ini file, then you should consider using get_browser()

[Chris Gwynne]

awasson thats dude, that works great!

I just got tired of having to work on workarounds for IE's lack of CSS knowledge so decided to f*** them altogether.

[mikis]

awasson thats dude, that works great!

Umm, just that you know, it is almost exactly the same as what I wrote, and you didn't want to try

[someonewhois]

awasson thats dude, that works great!

I just got tired of having to work on workarounds for IE's lack of CSS knowledge so decided to f*** them altogether.

Yeah, as mikis said, that's the same as his code - always best to try and give credit to the rigth person.

Also, cutting out 90% of the population generally isn't a great idea - unless it's like, an admin panel or something internal/specific.

[Chris Gwynne]

Umm, just that you know, it is almost exactly the same as what I wrote, and you didn't want to try

Sorry mikis

[awasson]

Umm, just that you know, it is almost exactly the same as what I wrote, and you didn't want to try

That's why I gave you credit mikis:

Take the one that mikis put up and then redirect the browser of the IE user away from your page to a page that tels them to upgrade.

Off Topic:


Then I went on a feverish rant about how your code was no different than mine except that your was contained on one line with the AND conjunction.... Bla bla bla.... Until it occured to me that the reason I used your code was for exactly that reason. oops

I'm going to blame my sensless rant on the flu.

And, yes mikis' is the creditee
PS:
Don't forget to convert to ether upper or lower case with these types of operations. It'll save you lots of troubleshooting time.

And no worries A-Drive. I agree about the CSS troubles in IE. Nothing but workarounds. See ya,
A

[mikis]

Heh, np It's not about credits, it is that people should try to *understand* answers to their questions, not just copy & paste code until it works.

And I agree: it is very rude do deny access to majority of internet users. I would rather use that code to display them nice Get Firefox logo

[KLB]

Keep in mind with all of these browser detection routines, it is not uncommon for alternative browsers like Firefox, Opera, etc., as well as proxies and other web browser related apps to report themselves as Internet Explorer. It is counter intuitive, but the browser's user agent string is actually not a great way of detecting what browser is being used.

I don't know fail safe tests for all browsers, but I do know that you can always detect Opera with the following JavaScript:

 if (window.opera) {[your instructions]}

Also you can feed IE stylesheets that no other browser will know to use with the following code:

		<!--[if IE 5]>
			<link href="/IE5.css" rel="stylesheet" type="text/css">
		<![endif]-->
		<!--[if IE 6]>
			<link href="/IE6.css" rel="stylesheet" type="text/css">
		<![endif]-->

Because non-MSIE browsers will see this code as a comment, they will ignore it and it will validate to W3C specifications, which is a very good thing.

[awasson]

Heh, np It's not about credits, it is that people should try to *understand* answers to their questions, not just copy & paste code until it works.

That's for sure

Have a good weekend,
Andrew

[Red Squirrel]

The problem with this is so many people clone their user agent to look like another browser, and for some reason, some people even make it look like IE. What's to be proud of by stating your using that crap?

So if you do stuff based on browsers these people who spoof their user agent may run into problems.

But they should not be screwing with their settings in first place. :P