PHP: session_cache_expire

Description

int session_cache_expire ( [int new_cache_expire] )

session_cache_expire() returns the current setting of session.cache_expire. The value returned should be read in minutes, defaults to 180. If new_cache_expire is given, the current cache expire is replaced with new_cache_expire.

The cache expire is reset to the default value of 180 stored in session.cache_limiter at request startup time. Thus, you need to call session_cache_expire() for every request (and before session_start() is called).

Пример 1. session_cache_expire() example


<?php



/* set the cache limiter to 'private' */



session_cache_limiter('private');

$cache_limiter = session_cache_limiter();



/* set the cache expire to 30 minutes */

session_cache_expire(30);

$cache_expire = session_cache_expire();



/* start the session */



session_start();



echo "The cache limiter is now set to $cache_limiter<br />";

echo "The cached session pages expire after $cache_expire minutes";

?>

Замечание: Setting new_cache_expire is of value only, if session.cache_limiter is set to a value different from nocache.

See also the configuration settings session.cache_expire, session.cache_limiter and session_cache_limiter().

session_cache_expire

lukasz at pilorz dot net
20-Nov-2005 05:49


I had a problem with session expiration time on a server where I didn't have access to php.ini. My solution was to use session_save_path with my own dir.

djmaze (AT) dragonflycms
23-Sep-2005 07:21


After recieving a "bogus" mark on a bug report i've tried to find out the differences between cache_expire and what was causing a session delete after 24 minutes.



cache_expire is used for cached session pages and has nothing to do with the session data



The garbage collector controls the session data and destroys sessions which are older then 1440 seconds (24 minutes) by default.



So to keep a session alive longer then 24 minutes (for example when a visitor tries to POST a huge message that took him 1 hour to type), you must modify the session.gc_maxlifetime thru ini_set()



Somehow i couldn't find anything in the PHP documentation regarding this and due to that me (and i think many others) got the wrong ideas regarding PHP sessions.

A few examples to fix session timeout are already posted below but in my opinion they all missed session.gc_maxlifetime

lance_rushing at hotmail dot com
17-Jun-2005 02:47


I've encountered the same problem of loosing focus when using IE and a javascript window.location.refresh/replace().



After fusing around I found that a <meta http-equiv="refresh" content="600"> works without move the focus on the parent frame's form.  The down side is loading up the browser history and an annoying 'click' in IE on the page load.

bermi�ferrer�[�at�]�akelos�[NO�SPAM]�com
03-Jun-2004 01:11


Hello,

Some of my customers asked me for a solution form their session not to expire when filling large forms. Sometimes it takes them more than 2 hours to submit (phone, desk customers...). 

I know I could have forced an ilayer to be refreshed dynamically and then include PHP code using session_cache_expire() function, but this refreshing a page changes the form focus. So I found this the only solution for them not to loose focus over their form element.



You can make a session not to expire by using this code.

Its a mixture of PHP and JavaScript and can be used on the same page were your code goes or it can be called using an ilayer/iframe from your page. 



I know this is not the best practice, but in some cases were user has no control over server globals and security is not important this can help.



Here is the code.



<?



//First of all we prevent browsers from caching the image

header("Cache-Control: no-store, no-cache, must-revalidate");

header("Cache-Control: post-check=0, pre-check=0", false);

header("Pragma: no-cache");

header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");

header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT"); 



//This piece of code returns a blank gif

if($_GET[img] > 0){ 

    header('Content-Type: image/gif');

    header("Content-Disposition: inline; filename=".time().".gif");

    echo base64_decode(str_replace("\n","","

R0lGODlhAQABAPcAAAAAAAAAQAAAgAAA/

wAgAAAgQAAggAAg/wBAAABAQABAgABA/

wBgAABgQABggABg/wCAAACAQACAgACA/

wCgAACgQACggACg/wDAAADAQADAgADA/

wD/AAD/QAD/gAD//yAAACAAQCAAgCAA/

yAgACAgQCAggCAg/yBAACBAQCBAgCBA/

yBgACBgQCBggCBg/yCAACCAQCCAgCCA/

yCgACCgQCCggCCg/yDAACDAQCDAgCDA/

yD/ACD/QCD/gCD//0AAAEAAQEAAgEAA/

0AgAEAgQEAggEAg/0BAAEBAQEBAgEBA/

0BgAEBgQEBggEBg/0CAAECAQECAgECA/

0CgAECgQECggECg/0DAAEDAQEDAgEDA/

0D/AED/QED/gED//2AAAGAAQGAAgGAA/

2AgAGAgQGAggGAg/2BAAGBAQGBAgGBA/

2BgAGBgQGBggGBg/2CAAGCAQGCAgGCA/

2CgAGCgQGCggGCg/2DAAGDAQGDAgGDA/

2D/AGD/QGD/gGD//4AAAIAAQIAAgIAA/

4AgAIAgQIAggIAg/4BAAIBAQIBAgIBA/

4BgAIBgQIBggIBg/4CAAICAQICAgICA/

4CgAICgQICggICg/4DAAIDAQIDAgIDA/

4D/AID/QID/gID//6AAAKAAQKAAgKAA/

6AgAKAgQKAggKAg/6BAAKBAQKBAgKBA/

6BgAKBgQKBggKBg/6CAAKCAQKCAgKCA/

6CgAKCgQKCggKCg/6DAAKDAQKDAgKDA/

6D/AKD/QKD/gKD//8AAAMAAQMAAgMAA/

8AgAMAgQMAggMAg/8BAAMBAQMBAgMBA/

8BgAMBgQMBggMBg/8CAAMCAQMCAgMCA/

8CgAMCgQMCggMCg/8DAAMDAQMDAgMDA/

8D/AMD/QMD/gMD///8AAP8AQP8AgP8A/

/8gAP8gQP8ggP8g//9AAP9AQP9AgP9A/

/9gAP9gQP9ggP9g//+AAP+AQP+AgP+A/

/+gAP+gQP+ggP+g///AAP/AQP/AgP/A/

///AP//QP//gP///yH5BAEAAP8ALAAAA

AABAAEAAAgEAP8FBAA7"));

    exit;

}



?>



<!-- HERE YOU CAN INSERT THE HTML OR PHP CODE -->



<img name="keepUpdated" src="<?=$_SELF?>?img=999">

<script language="Javascript">

<!--

var updateEvery = 30;//Seconds

function keepUpdated() {

    timer=setTimeout("updateImage()",1000*updateEvery)

}

function updateImage() {

    var randNum = Math.floor(Math.random()*999);

    document.images.keepUpdated.src ="<?=$_SELF?>?img="+randNum;

    keepUpdated();

}

keepUpdated();

//-->

</script>



I hope this can be helpful for someone.



Bermi Ferrer