how to run a code at timed intervals?

[pepe-le-pew]

what i'd like to accomplish:
- a member logs in.
- a time stamp is being send to a database
- every minute this member stays on a page, a query is made to the database to update the time stamp.
- a cron job is being made every 3 minutes to query the db and check if the time stamp is 2 minutes older than the actual time.
-if it is, the member is considered logged-out. and the time stamp in the db is being reset.
-if it isn't, the time stamp is being set to the actual time.

the code is to be placed on the php page a visitor to my site is at (in a required footer.php, to be exact).
i've tried using sleep(60) inside an infinite loop (ie: while(2 == 1+1)), but even by experimenting with its placement inside the loop, and flush(), i can't seem to get the desired result. :/

i could get the data i need by recording the PHPSESSID for that particular session, and, using a cron job, un-log the member automatically if the session has been destroyed, but even though i was told the session files are stored in a /tmp folder on my site, i've never been able to see them, let alone access them.

any idea how to accomplish this without using a session time out?

thanks in advance 🙂

[balsdorf]

I don't have the exact details of this as I am at work and don't have time to play with it myself, but what I would use Javascipt on the client side to notify you they are logged in.
Simply have a hidden image on the page that points to a php script. Have javascript refresh the image every 60 seconds and when it calls the PHP script, have the script update the database.
Example:
<image src="updateTimestamp.php?SID=$sid" name="updateImage" width="1" height="1">
<script>
function updateImage() {
document.images["updateImage"].src = "updateTimestamp.php?SID=$sid";
}
settimeout(600, updateImage());
</script>

Make the php file return a transparent, 1 by 1 gif so no errors show up in the browser. You will probably have to tweak the javascript code as I am not a javascript guru. If you get it working, let us know. I always wonder if my suggestions are used.

[pepe-le-pew]

Thanks Bryan,

It something I had in mind too, as I've seen it's done this way by services like "Human Click", and "Click Chat Sold".
Unfortunately my javascript knowledge is pretty non-existent, but I'll give it a try using your code, and the ones from "HM" and "CCS". 😉

And I'll let you know if I get anywhere. 🙂

Denis

[pepe-le-pew]

I'm not getting anywhere. 🙁

How do I make the php page return an image? :/
How would my php code detect the image request from the page containing the javascript? :/
I actually don't have a clue how to do any of that, lol.

Shame, as it looks like the way to go. 🙁

Thanks anyway Bryan. 🙂

Denis