Detect referer and write HTML if not internal

[Adam_C]

Would anyone have a bit of PHP script handy for this:

1. Detect the referrering URL
2. If referrer is internal (from same domain) or the is no referrer do nothing

otherwise

write a line of HTML

[Receptional Andy]

Hi Adam,

That's pretty straightforward. The visitors referrer (unless they block/disable it) is contained in the $_SERVER[HTTP_REFERER] server variable [php.net]. You can search this for your domain name using a php string function such as strpos [php.net]:

<? 
// check for occurance of example.com in the referrer. strpos wil return 0 if it isn't found
if (strpos("example.com",$_SERVER[HTTP_REFERER])==0) {
echo "External or no referrer";
}
else {
echo "Internal referrer";
}
?>

[Adam_C]

Cheers Andy