session_cache_limiter> <Funções para Sessão
Last updated: Fri, 24 Feb 2012

session_cache_expire

(PHP 4 >= 4.2.0, PHP 5)

session_cache_expire — Retorna o prazo do cache atual

Descrição

int session_cache_expire ([ int $new_cache_expire ] )

session_cache_expire() retorna a atual configuração de session.cache_expire.

O prazo para o cache expirar e retornado ao padrão de 180 minutos guardado em session.cache_limiter no inicio do script. Então você precisa usar session_cache_expire() para cada requesição (e antes que session_start() seja utilizada).

Parâmetros

new_cache_expire

Se new_cache_expire é dado, o cache atual é modificado por new_cache_expire.

Nota: Defina o valor de new_cache_expire, somente se session.cache_limiter é definido como um valor diferente de nocache.

Valor Retornado

Retorna a configuração atual de session.cache_expire. O valor retornado deve ser lido em minutos, padrão para 180.

Exemplos

Exemplo #1 Exemplo da session_cache_expire()

<?php

/* Define o limitador de cache para 'private' */
session_cache_limiter('private');
$cache_limiter = session_cache_limiter();

/* Define o limite de tempo do cache em 30 minutos */
session_cache_expire(30);
$cache_expire = session_cache_expire();

/* Inicia a sessão */
session_start();
echo "O limitador de cache esta definido agora como $cache_limiter<br />"; 
echo "As sessões em cache irão expirar em $cache_expire minutos";
?>

Veja Também



session_cache_limiter> <Funções para Sessão
Last updated: Fri, 24 Feb 2012
 
User Contributed Notes
session_cache_expire
karel at narfum dot org
26-Apr-2011 11:33
What most people also don't know, is that most Linux distributions (Debian and Ubuntu for me atleast) have a cronbjob that cleans up your session dir using the value set in the global /etc/php5/php.ini (which defaults to 24mins). So even if you set a value larger in your scripts, the cronbjob will still cleanup sessions using the global value.

If you run into that situation, you can set the global value higher in /etc/php5/php.ini, disable the cronjob or even better, do your own session cleanup in a non-systemwide directory or a database.
Anonymous
20-Feb-2008 05:50
The manual probably doesn't stress this enough:

** This has nothing to do with lifetime of a session **

Whatever you set this setting to, it won't change how long sessions live on your server.

This only changes HTTP cache expiration time (Expires: and Cache-Control: max-age headers), which advise browser for how long it can keep pages cached in user's cache without having to reload them from the server.
info at ericbontenbal dot nl
08-Aug-2006 09:34
you can change the max lifetime for a session with the function ini_set().

<?php
ini_set("session.gc_maxlifetime", "18000");
?>
This will set the max lifetime of the script to 5 hours. You have to use this in every script that you want to change the default lifetime for.

if you want to know the lifetime of your current script, you can use:

<?php
echo ini_get("session.gc_maxlifetime");
?>
lukasz at pilorz dot net
20-Nov-2005 03:49
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 04:21
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 11:47
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
02-Jun-2004 10:11
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

session_cache_limiter> <Funções para Sessão
Last updated: Fri, 24 Feb 2012