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- Session 函数
session_status
(PHP 5 >= 5.4.0, PHP 7, PHP 8)
session_status — 返回当前会话状态
说明
session_status(): intsession_status() 被用于返回当前会话状态。
返回值
-
PHP_SESSION_DISABLED会话是被禁用的。 -
PHP_SESSION_NONE会话是启用的，但不存在当前会话。 -
PHP_SESSION_ACTIVE会话是启用的，而且存在当前会话。
参见
- session_start() - 启动新会话或者重用现有会话
User Contributed Notes 10 notes
up down 62 sasi dot viragelet at gmail dot co ¶7 years ago
Maybe depending on PHP settings, but if return values are not the above, then go for this:
_DISABLED = 0
_NONE = 1
_ACTIVE = 2
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2
polygon dot co dot in at gmail dot com ¶8 months ago
Note session_status() is for file based session only.
DB based session status needs to have custom function based on table structure.
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38
coder dot ua at gmail dot com ¶8 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();
?>
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13
info at eurocron dot de ¶3 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 $_SESSION, but if you want to write,
you need session_start() again.
As a shorthand you can use
@session_start()
with the @ at the beginning to suppress the
PHP notice "A session had already been started - ignoring session_start()"
As stated in the manual for session_start(), a second call will do no harm,
it will be simply ignored. But you need the @, if you don't want to get the notice.
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6
php at pointpro dot nl ¶9 years ago
The advice of ive_insomnia at live dot com should be taken with great care.
First of all, while his use case for session_status is valid, a simpler way to avoid the warning is:
<?php
if (!isset($_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.
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2
Ben (aocool at msn d0t com) ¶6 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 () ) );
}
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2
ayon at hyurl dot com ¶5 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;
}
}
?>
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0
Ollea ¶8 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 ?
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-3
solaimanshah059 at gmail dot com ¶3 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();
}
?>
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-19
php at kenman dot net ¶8 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
add a note
官方地址：https://www.php.net/manual/en/function.session-status.php