help understanding some $_SERVER variables..

[Dragen]

Hi,

 

Could someone please tell me what all of these $+SERVER variables mean and/or do? I've been searching for a bit and can't seem to find anything, even on php.net's predefined variable list and I'm trying to find ways of logging ip's, browser versions etc.

 

• $HTTP_X_FORWARDED_FOR
  
• $HTTP_VIA
  
• $HTTP_CLIENT_IP
  
• $HTTP_PROXY_CONNECTION
  
• $FORWARDED_FOR
  
• $X_FORWARDED_FOR
  
• $X_HTTP_FORWARDED_FOR
  
• $HTTP_FORWARDED
  

 

None of them actually seem to work on my local server I receive this kind of error:

Notice: Undefined index: FORWARDED_FOR in C:\Program Files\wamp\www\counter.php on line 13

I'm presuming this is either because I don't have those server variables installed/enabled or they don't actually exist and have just sprouted up among the internet as a means of distracting us...

 

any help would be great!

[pocobueno1388]

If you just put this in you code:

 

<?php 

echo '<pre>';
print_r($_SERVER);
echo '</pre>';
	  
?>

 

That will give a list of all the server variables, and what values they hold for that specific page.

To get an IP address, use $_SERVER['REMOTE_ADDR'];

[Dragen]

Thanks.

The main one I undrstand are these two:

$_SERVER['REMOTE_ADDR']; //get ip
gethostbyaddr($_SERVER['REMOTE_ADDR']); //get ip hostname
$_SERVER['HTTP_REFERER']; //page referer

There was another way of getting the ip hostname, but I can't use it on my local server.

I'm just trying to figure out what the other's do, so I can decide if it's worth the hasle of trying to get them to work.. if I can.

[trq]

Here is a list describing all the server variables and what they do.

[Dragen]

I've already searched through that. None of them are listed on there, although a couple of people have used them in code examples, but no explaining what they do.

Also, how do I go about enabling the use of server values that aren't enabled at the moment?