Check if PHP session has already started

Question

I have a PHP file that is sometimes called from a page that has started a session and sometimes from a page that doesn\'t have session started. Therefore when I have s

Answer 1

PHP 5.4 introduced session_status(), which is more reliable than relying on session_id().

Consider the following snippet:

session_id('test');
var_export(session_id() != ''); // true, but session is still not started!
var_export(session_status() == PHP_SESSION_ACTIVE); // false

So, to check whether a session is started, the recommended way in PHP 5.4 is now:

session_status() == PHP_SESSION_ACTIVE