getenv("HTTP_REFERER") returns empty string!?

mail("My  Name <me@domain.com>", date("D, M j, Y - h:i a T", time()), "Connection from " . getenv("REMOTE_HOST") . " referred by " . getenv("HTTP_REFERER"), "From: \"Server Access!\" <server@site_server.com>");

I put this on my index page to mail me whenever someone visits my site. The referer returns the URL of my own bookmarks page, sited on the same server as this site, but under a different virtual domain name, but when others visit the site, the referer is blank, perhaps an empty string or a NULL. Why is the referer not being detected? Is there a way to fix it? Bonus question: can I get the IP address resolved with a reverse domain name lookup directly inside this little script?
mschrimsherAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

JakobACommented:
when a page is reached through javascript  (fx  self.location.href="yourpage.html")  the HTTP_REFERER is empty.  if people are directed to your site from a google search HTTP_REFERER will be set only if googles server remebers to set it in a header before they redirect.

So you cannot expect referrer to always be set.

You should not fetch it with the getenv function though, use the $_SERVER array:

 mail("My  Name <me@domain.com>", date("D, M j, Y - h:i a T", time()), "Connection from " . getenv("REMOTE_HOST") . " referred by " . $_SERVER["HTTP_REFERER"], "From: \"Server Access!\" <server@site_server.com>");

regards JakobA
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
JakobACommented:
0
mschrimsherAuthor Commented:
Jakob: Thanks! I find that about half the referers are being reported now, so I guess I just had a run of bad luck in the beginning. I do get a lot of Google traffic due to AdSense, so that may be part of it--I will correlate the IP addresses to the blank referers and see if there's a pattern. The reference to $_SERVER that you sent said that it was a version 4.1 introduction, and I am using
a 3.x version of PHP now. My ISP offers 4.x as as module, and I have planned to move over for other reasons anyway, so when I do, I will change to $_SERVER. Thanks again!
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
PHP

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.