session error??

[chaiwei]

Hi I got this with this.

 

Warning: Unknown: Your script possibly relies on a session side-effect which existed until PHP 4.2.3. Please be advised that the session extension does not consider global variables as a source of data, unless register_globals is enabled. You can disable this functionality and this warning by setting session.bug_compat_42 or session.bug_compat_warn to off, respectively in Unknown on line 0

 

Here is my script

<?php 
session_start(); 
$_SESSION['a'] = $_POST['lala'];
$a = 'abc';
?>

 

The $_POST['lala'] is not a defined variable;

It is same as NULL, (will cause the warning appear also)

 

How was it processing? Please advice?

 

[Bricktop]

Hi chaiwei,

 

It's probably because $_POST['lala'] contains no data.  Does it still appear if $_POST['lala'] is not null?

[chaiwei]

Yes, the $_POST['lala'] is a variable not yet defined.

 

The warning will dissapear  if I defined $_POST['lala'] equals to empty string

$_POST['lala'] = '';

or anything else.

 

Another thing I discover was it will be register global issues.

My PHP version was 5.2.0 and register_global was turn off.

 

You try run this script:

1. first step

<?php 
session_start();  
$_SESSION = array();
$a = 'I will be in session for the second time';
print_r($_SESSION);
$_SESSION['a'] = $abc; 
?>

Array ( ) 
Warning: Unknown: Your script possibly relies on a session side-effect which
existed until PHP 4.2.3. Please be advised that the session extension does not consider
global variables as a source of data, unless register_globals is enabled. 
You can disable this functionality and this warning by
setting session.bug_compat_42 or session.bug_compat_warn to off, 
respectively in Unknown on line 0

 

2. Remove the $_SESSION = array();

And refresh again.

Then you will see

Array (     [a] => I will be in session for the second time ) 
Warning: Unknown: Your script possibly relies on a session side-effect which
existed until PHP 4.2.3. Please be advised that the session extension does not consider
global variables as a source of data, unless register_globals is enabled.
You can disable this functionality and this warning by setting session.bug_compat_42 or session.bug_compat_warn to off, respectively in Unknown on line 0

 

 

[gevensen]

you have to submit your post data no?

if your passing along a post to another page it will pick it up but for example on the same page it would be

if (isset($_POST['submit'])) 
{ // if form has been submitted 
switch ($_POST['submit'])
{
case 'Submit':
$_SESSION['lala']=$_POST['lala'];
// the you can pass it along to the session 

break;
case default:
break;

}
}

[gevensen]

you can also check to see if your post is set or not by

<?php 
session_start(); 
if(isset($_POST['lala'])
{
$_SESSION['a'] = $_POST['lala'];
$a = 'abc';
}
else
{
echo "SESSION NOT SET!";
}
?>

[PFMaBiSmAd]

Read the error message and do what it says -

You can disable this functionality and this warning by setting session.bug_compat_42 or session.bug_compat_warn to off

Stop and start your web server to get any change made to the master php.ini to take effect and confirm that the settings were actually changed using a phpinof() statement in case the php.ini that you are changing is not the one that php is using.

 

And yes, you should always make sure that your form was submitted before you access any of the form data, otherwise your code will not operate as expected.