question about $_SESSION

Discussion in 'PHP' started by Dirty-Rockstar, Aug 14, 2007.

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  1. #1
    This is just a snippet of code from endless templates of things i have:


    
session_start();
require "global_func.php";
if($_SESSION['loggedin']==0) { header("Location: login.php");exit; }

require "header.php";

include "mysql.php";
    PHP:
    look at this part here

    
$_SESSION['loggedin']
    PHP:

    i cannot find anywhere on this page or the included pages or the included pages on the included pages where $_SESSION is combined with the word "loggedin". it looks like something that resembles $_POST[whatever] and "whatever" would come from a name in a form.

    so where is "loggedin" coming from. can you give me a cheap example?
     
    Dirty-Rockstar, Aug 14, 2007 IP
  2. killerj

    killerj Active Member

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    #2
    open login.php , you'll find that 'loggedin' is set to 1 somewhere there after the auth. of user from the db was successful , thereby creating a new session for that user .
     
    killerj, Aug 14, 2007 IP
  3. rodney88

    rodney88 Guest

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    #3
    That's the whole point of sessions - it allows you to maintain data between page requests. If you add data to the $_SESSION array on one page, you can access it on the next (provided both scripts first call session_start()).

    The loggedin value could be set anywhere in the whole script - but given the name of it, it's going to be in the login script as killerj said.

    Strictly speaking, there's a mistake in the code which probably caused the confusion. The code checks for the value of $_SESSION['loggedin'] being false. You said none of the code for the execution of that script makes any mention of $_SESSION['loggedin']. Therefore there are no guarantees that that value has even been set (and developing under E_NOTICE conditions would generate an "undefined index" message). The correct way of checking the value would be 
    if( ! isset($_SESSION['loggedin']) || $_SESSION['loggedin'] == 0 )
    PHP:
    , or to combine both parts of the conditional: 
    if ( empty($_SESSION['loggedin']) )
    PHP:
     
    rodney88, Aug 15, 2007 IP