Entry

How can I detect in PHP whether a request originated via the browser's address or via a link ?

Jun 24th, 2004 12:04
Philip Olson, David Crossley,

Although not perfect you can check for the HTTP predefined variable 
named HTTP_REFERER so for example:
  if (isset($_SERVER['HTTP_REFERER'])) {
    echo "Hi, you came from the link: " . $_SERVER['HTTP_REFERER'];
  } else {
    echo "Not sure where you came from!";
  }
If you create the links yourself then you could do various things like 
pass a variable via GET (in the URL) and check that, or, use a 
SESSION, but most likely that's not your question.