tracking HTTP_REFERER with personal firewalls

brett manages to, why can't i?

[jamie]

i use norton personal firewall which disguises my referer. this is a standard setting and as such is used by people all over the web with personal firewalls.

when i pass the HTTP_REFERER (either in php or cgi) to a script (such as a 'tell a friend' script) the HTTP_REFERER is always blank, unless i manually deactivate my firewall.

however....
if i click on the 'email a friend' link at the bottom of this very page, the referrer is shown on the next page, even when my firewall is active!

how does brett do it?

[andreasfriedrich]

The thread you want to send is coded into the query string. No referrer is used.

[webmasterworld.com...]

Andreas

[jamie]

aaah

thanks andreas. with our static site this would not be possible (unless i manually copy in the link to 100s of pages ;-)

thanks for explaining

[jamie]

hi andreas,

i have been trying to work around this, so that if no referer is given, then my std url is displayed and sent to the next page:

$fullurl = "{$HTTP_REFERER}";
$stdurl = "http://www.mydomain.com";

if(isset($fullurl))
{
echo "Recommended page: $fullurl<br> " ;
echo"<input type=hidden name=link value=$fullurl>";
}
else
{
echo "Recommended page: $stdurl<br> " ;
echo"<input type=hidden name=link value=$stdurl>";
}

this doesn't work though :-(

any tips for a beginner?

many thanks

<added>

don't worry i've done it. i just check to see if http_referer contains something

if(eregi("http", $HTTP_REFERER))

instead of using isset

cheers

[andreasfriedrich]

This should work:

$url = $_SERVER['HTTP_REFERER'] == '' 
? 'http://www.ac.com/' 
 : $_SERVER['HTTP_REFERER']; 
echo "Recommended page: $url<br> 
<input type=hidden name=link value=$url>"; 

It tests whether the referrer string is empty or not. If it is it assigns the standard URL to $url. Otherwise it uses the referrer string.

Andreas

[jamie]

a slightly more elegant solution than mine ;-)

thanks

[andreasfriedrich]

>>with our static site this would not be possible (unless i
>>manually copy in the link to 100s of pages ;-)

This will all depend on the right tools. The modified tagrep script [webmasterworld.com] would enable you to do that very easily.

Andreas

[jamie]

andreas,

thanks for input,

but i don't understand how i can use this tool to code in the link for each page?

each page would need its own unique link something like mydomain.com/tellfriend.php?myreferringpage.htm. and the php tell a friend script would then use that code to identify the exact page to send.

[andreasfriedrich]

>>each page would need its own unique link

Thatīs just what the script will do. If you had a website structure like this

/index.html 
/ac/index.html 
/ac/cds.html 
/ac/pix.html 
/jmc/index.html 
/jmc/pix.html 

the script would generate a link in each file that would look like this:

friends.cgi?file=http://www.site.com/index.html 
friends.cgi?file=http://www.site.com/ac/index.html 
friends.cgi?file=http://www.site.com/ac/cds.html 
friends.cgi?file=http://www.site.com/ac/pix.html 
friends.cgi?file=http://www.site.com/jmc/index.html 
friends.cgi?file=http://www.site.com/jmc/pix.html 

if you called it like that:

./tagrep __DOCUMENT_ROOT__/ '^friends.cgi$' \ 
'sub{(my $n = $File::Find::name) =~ \ 
s!^__DOCUMENT_ROOT__!http://www.site.com!; \  
return "friends.cgi?file=$n";}' href 

You would need to replace __DOCUMENT_ROOT__ with your DocumentRoot [httpd.apache.org].

Andreas

[jamie]

wow andreas, thank you very much!

looks like it will be a late night tonight trying all this out ;-)