HTTP_REFERER is null

[gobob]

I have a normal HTML link on an html page on one site pointing to a test.php file on another site.

 

I want to get the URL of the refering page using PHP, but have so far been unsuccessful.

 

Both $_SERVER['HTTP_REFERER'] and getenv('HTTP_REFERER') provide null results.

 

Also, phpinfo() does not display the HTTP_REFERER.

 

I can successfully get the remote IP addresses with $_SERVER['REMOTE_ADDR'].

 

JavaScript successfully displays the correct refering URL with:

 

<script language=javascript>document.write(referer);</script>

 

so, apparently, the header information is available.

 

I have tried this with MSIE and Firefox browsers.

 

I have also placed the test.php file on two different servers, but in each case PHP failed to find the refering URL.

 

Any suggestions would be helpful.

[lemmin]

Have you tried a simple

echo $_SERVER['HTTP_REFERER'];

?

 

I think PHP will actually display a warning if you try to use it and it isn't available, so I can only assume it is something in your code.

[gobob]

I have tried that.

 

I believe the key is that phpinfo() displays nothing for HTTP_REFERER.

 

In that case I would not expect and PHP variable or function to provide the referer URL.

 

Since I am new at PHP, I have to ask, should PHP display a value for HTTP_REFERER when a .php file is requested by a normal HTML link?  Or am I striving in vain for something that normally does not work?

[lemmin]

Does

print_r($_SERVER);

show anything?

 

This is a guess but, is it possible that the server you are running it on has some kind of redirection that might erase that value?