(PHP >=5.4.0)
session_status — Returns the current session status
session_status() is used to return the current session status.
PHP_SESSION_DISABLED if sessions are disabled.
PHP_SESSION_NONE if sessions are enabled, but none exists.
PHP_SESSION_ACTIVE if sessions are enabled, and one exists.
adrian (2013-06-25 07:33:37)
>The use of this function is lies more towards status management: change the behavior of a script when sessions are disabled altogether, for example.
On that note:
<?php
if( session_status() === PHP_SESSION_NONE ){ session_start(); }
?>
This way, you won't try to start a session if a) a session already exists, or b) sessions are disabled.
php at pointpro dot nl (2013-04-16 07:06:00)
The advice of ive_insomnia at live dot com should be taken with great care.
First of all, while his use case for session_status is valid, a simpler way to avoid the warning is:
<?php
if (!isset($_SESSION)) { session_start(); }
?>
The example of session_status uses the raw values of constants (2 in this case) created specifically for the purpose of not having to use magic numbers.
Better code would be:
<?php
if (session_status() !== PHP_SESSION_ACTIVE) {session_start();}
?>
The same can be done using
<?
if (session_id() === "") { session_start(); }
?>
The use of this function is lies more towards status management: change the behavior of a script when sessions are disabled altogether, for example.
ive_insomnia at live dot com (2013-02-25 02:06:36)
simple session_start() request to avoid warning:
<?php
if (!$_SESSION) {session_start();}
// your code
?>
Or similar code works, but give a warning.
<?php
if(session_status() != 2) {session_start();}
// your code
?>
This option work fine without warning.
0 = PHP_SESSION_DISABLED
1 = PHP_SESSION_NONE
2 = PHP_SESSION_ACTIVE