referring URL

willl

Can anyone tell me how reliable a php script can be fetching the referring URL?

Would anyone know of any factors that might prevent php from getting this information?

Many thanks in advance,

Will.

luiddog

<? echo $_server['http_referer'] ?>

willl

Is this a 100% reliable method?

luiddog

I use it and it works. Never had a problem.

Weedpacket

willl wrote:
Is this a 100% reliable method?

No, and there is no 100% reliable method, because any method would have to rely on the client saying where it was referred from. And you can never trust the client.

willl

Ah, this is what I was worrying about. Can you give more precise notes on why a referer wouldn't be logged. Is it soemthing to do with browser settings? or 3rd part software?

Many thanks!

MarkR

luiddog wrote:
<? echo $_server['http_referer'] ?>

No, that's wrong. It should be

$_SERVER['HTTP_REFERER']

PHP variable names and array indexes are both case sensitive. If you're wondering why it's HTTP_REFERER not HTTP_REFERRER, that's because Netscape's developers spelt it wrong when they first introduced it and ever since the spelling error has been maintained for compatibility.

Detecting the referrer is not 100% reliable as it can (and sometimes is) be blocked or disabled by web browsers, proxy servers, or other tools (some software "Firewall" or other desktop security applications block it).

Mark