[Joshdw]

Hello once again DiC members!
I have stumbled across a problem that is really really bugging me, I can't seem to figure out why it is happening.

So I have a PHP page that simply adds the visitors referring url to a database table, and then redirects them to another page. This is the code (the very first lines of code, it's where I "grab" the referring url):

<?php 
include 'dbconfig.php';

if (isset($_SERVER['HTTP_REFERER'])) {
	$ref = strtoupper(htmlspecialchars($_SERVER['HTTP_REFERER']));
	$ref = str_replace("HTTP://", "", $ref);
	$ref = str_replace("HTTPS://", "", $ref);
	$ref = str_replace("WWW.", "", $ref);
	$refsplit = explode('/', $ref);
	$ref = $refsplit[0];
} else {
	$ref = "NA";
}

It always returns an empty value (or if I remove the isset:

Undefined index: HTTP_REFERER on line 3

)

Now if I post the exact same code on a diferent page (for example, the index page) it will work fine. Could it have something to do with the file where the code is written, doesn't actually render a page, it just redirects?

[codeprada]

It depends on where they're coming from. It's not a coding error but some servers don't send the HTTP_REFERER header. You will see that with anonymous proxies and so forth. Users can also remove it with a firewall if configured to do so.

So you see HTTP_REFERER isn't very reliable. My suggestion is to leave the if (isset($_SERVER['HTTP_REFERER'])) where it is.

[Joshdw]

I understand that, but the thing is, the same code works perfectly on a diferent page (that renders a layout and that doesn't redirect), with the same referer.

[Joshdw]

Bump, still need help! Would really like to find out the problem as soon as possible, it's been bugging me for hours.
Thanks!

[CTphpnwb]

It depends on how the page is being accessed. Look at this code:
refer.php:

<?php
if (isset($_SERVER['HTTP_REFERER'])) {
	echo $_SERVER['HTTP_REFERER'];
} else {
	echo "No referrer.";
}
?>

If I go to local host and click on the link to refer.php then I get an address. If I open the same link in a new window, it says "No referrer."

[Joshdw]

Woah, thanks so much for the reply, I can't believe it was something so silly.
Kudos to you!