Maybe depending on PHP settings, but if return values are not the above, then go for this:
_DISABLED = 0
_NONE = 1
_ACTIVE = 2
session_status
(PHP 5 >= 5.4.0, PHP 7, PHP 8)
session_status — Возвращает состояние текущей сессии
Список параметров
У этой функции нет параметров.
Возвращаемые значения
-
PHP_SESSION_DISABLED, если механизм сессий отключён. -
PHP_SESSION_NONE, если механизм сессий включён, но сессия не создана. -
PHP_SESSION_ACTIVE, если механизм сессий включён и сессия создана.
Смотрите также
- session_start() - Стартует новую сессию, либо возобновляет существующую
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User Contributed Notes 10 notes
sasi dot viragelet at gmail dot co ¶
9 years ago
info at eurocron dot de ¶
5 years ago
Use always session_status(), to check if a session is already started and active.
if(session_status() !== PHP_SESSION_ACTIVE) session_start();
or
if(session_status() === PHP_SESSION_NONE) session_start();
Don't use
if(!isset($_SESSION)) session_start();
or
if(session_id() === "") session_start();
They will not work properly after a call to session_write_close().
Both functions will continue to report, that the session exists.
And this is right, you can read from $_SESSION, but if you want to write,
you need session_start() again.
As a shorthand you can use
@session_start()
with the @ at the beginning to suppress the
PHP notice "A session had already been started - ignoring session_start()"
As stated in the manual for session_start(), a second call will do no harm,
it will be simply ignored. But you need the @, if you don't want to get the notice.
coder dot ua at gmail dot com ¶
11 years ago
Universal function for checking session status.
<?php
/**
* @return bool
*/
function is_session_started()
{
if ( php_sapi_name() !== 'cli' ) {
if ( version_compare(phpversion(), '5.4.0', '>=') ) {
return session_status() === PHP_SESSION_ACTIVE ? TRUE : FALSE;
} else {
return session_id() === '' ? FALSE : TRUE;
}
}
return FALSE;
}
// Example
if ( is_session_started() === FALSE ) session_start();
?>
polygon dot co dot in at gmail dot com ¶
3 years ago
Note session_status() is for file based session only.
DB based session status needs to have custom function based on table structure.
php at pointpro dot nl ¶
11 years ago
The advice of ive_insomnia at live dot com should be taken with great care.
First of all, while his use case for session_status is valid, a simpler way to avoid the warning is:
<?php
if (!isset($_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.
Ben (aocool at msn d0t com) ¶
8 years ago
Just another function to determine whether the session has already started:
function is_session_started () {
return function_exists ( 'session_status' ) ? ( PHP_SESSION_ACTIVE == session_status () ) : ( ! empty ( session_id () ) );
}
ayon at hyurl dot com ¶
8 years ago
This is how the session_status() works:
<?php
function session_status(){
if(!extension_loaded('session')){
return 0;
}elseif(!file_exists(session_save_path().'/sess_'.session_id()){
return 1;
}else{
return 2;
}
}
?>
Ollea ¶
10 years ago
If you started and closed a session then test ( session_id() === '' ) to check if a session is active it won't work, session_id() returns an ID even if the session is closed.
Anybody knows another way before PHP 5.4 to check if a session is really not currently active ?
solaimanshah059 at gmail dot com ¶
6 years ago
Here some Good example for your understandingl
<?php
if( session_status == PHP_SESSION_NONE ) // if session status is none then start the session
{
session_start();
}
?>
old Practice we were using.
<?php
if( !( isset($_SESSION) ) ) // if the session is no set then start to
new session
{
session_start();
}
?>
php at kenman dot net ¶
11 years ago
The purpose of this functionality can aid you specifically in cases where code -- prior to your current code -- might have opened a session and then closed it.
Specifically, depending on $_SESSION, session_id(), and the SID constant to determine if a session is active will FAIL if a session has previously been opened & closed within the same request cycle.
Please see the original bug report here:
https://bugs.php.net/bug.php?id=52982
