Is it good practice to detect browsers like this..?

[londres9b]

We all know that browser compatibility is almost always an issue. What I'd like to know is if this way of telling which browser the user is using is a good practice.

<?php
$who = strtolower($_SERVER['HTTP_USER_AGENT']);

if(preg_match("/msie/", $who)) { 
	//code for IE 
}
elseif(preg_match("/mozilla/", $who)) { 
       //code for Firefox
}
else { 
	//code for Other Browsers
}
?>

Thank you in advance.

[dlite922]

try this:

http://api.jquery.com/jQuery.browser/

Dan

[londres9b]

It's interesting but if the user doesn't have javascript ..:(
So you don't recommend using the php code above?

[TheServant]

If it works, it works. I suggest you do some thorough testing though. But yeah, it looks OK to me. Probably even worth looking at the jQuery Browser code dlite922 posted to see how they do it and if you can improve yours at all.

[Dormilich]

as mentioned in dlite992’s link, you should prefer feature detection over browser detection. the user agent string can be manipulated easily, after all.

[TheServant]

I haven't really thought about this too much, but why would anyone want to manipulate their agent string? If all it does is choose what content is served, there is not really a security risk is there? But, I think that feature detection is simpler and a better choice. Do you know how it handles IE "having" some features, but not really "having" them?

[zorgi]

I like to use conditional comments for detection of IE browsers.

[Markus]

You might manipulate your user-agent header to gain access to areas that only permit certain user-agents to view content.

By the way, using preg_match to match simple strings is wasteful. Use strpos instead.

[londres9b]

Thank you all

[pradeepkr13]

use php function get_broswer();

But it's not advisable and not a good practice to write browser dependable code.