Can a session variable be accessed on a background php page the user does not see?

Posted on 2014-09-05
Medium Priority
Last Modified: 2014-09-05
if (isset($_SESSION['user']) && $_SESSION['user'] != '') {
  $username = $_SESSION['user'];

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I have a file upload form. I get a file id number from the url, and use AJAX to send it to a background php page to upload a file. I want that background php page that the user never sees to get the username from a session variable and use that name to cross check the file id from that url by checking the database to verify the file id matches with the username in the same table row.

When I try this, the session variable appears to be empty or it cannot be accessed by a background php page.

My second option would be to send in the url a user id in addition to a file id. Then access the database to be sure the two id's go together. But I think this would be less secure.

1. My question is; Is it true session variables cannot be accessed by background php pages?
2. If yes, then how might I perform a cross check without the session variable? Thanks.
Question by:kadin
  • 2
LVL 84

Accepted Solution

Dave Baldwin earned 2000 total points
ID: 40307221
No, 'background' has nothing to do with it.  I use sessions on 'invisible' pages all the time.  But the page Must Always have session_start() at the top of it.  That's how PHP picks up the current session.  On several pages, I even start the session with an AJAX call.  session_start() is the key.

Author Closing Comment

ID: 40307230
Thanks. That didn't even occur to me.
LVL 84

Expert Comment

by:Dave Baldwin
ID: 40307237
You're welcome, glad to help.

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