[Workaround found] CodeIgniter 3.0 cannot access native $_SESSION

Just a guess:

session_start() starts a new session or resumes an existing session". By doing another page request without calling session_start you will loose you session. You MUST call session_start() to resume your session. Why do you call session_start()?

In CodeIgniter it is sufficient to use $this->load->library('session'); You session will be available with every page request and you can access it using $this->session.

I think var_dump($_SESSION); and var_dump($this->session); will give you the same result. However I never checked it and cannot check it now.

I have call session_start() in my external script:

PHP Code:

<?php
    if(!isset($_SESSION)){
        session_start();
    }
    var_dump($_SESSION); 


Yes var_dump($_SESSION) and var_dump($this->session->all_userdata()) will give the same result, but it has nothing to do with my problem.

My problem is:

$_SESSION in my non-codeigniter php application is different from $_SESSION in codeigniter application.
Thus Codeigniter and non-codeigniter php application cannot share session.

You could do a check when the user enters your CI application.
If you have created your sessions in the other app with the normal $_SESSION functionality you could just do something like this when the user enters the CI app:

PHP Code:

if(isset($_SESSION['whatever'])) {
    # add it to the CI session
    $this->session->userdata....
} 


You could also do it the other way around. Just make sure to validate them when passing them between the scopes.