...thanks, I should have been more specific - how can I access referrer url field from the
extension code? I realize it might be more of a php question rather then MW.
kind of expected this to be put into $wgRequest object since referrer is part of the HTTP
request header, but I couldn't find it there.
Which hook can I use for the following? (in the case it looks reasonable)
$wgHooks['somehook'] = 'run_greeting';
$msg = function_of(somehow_get_referrer_url());