セッション関数
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.
session_cache_expire
(PHP 4 >= 4.2.0, PHP 5)
session_cache_expire — 現在のキャッシュの有効期限を返す
説明
int session_cache_expire
([ string $new_cache_expire
] )
session_cache_expire() は現在の session.cache_expire の設定を返します。
リクエストがあった時点でキャッシュの有効期限は session.cache_limiter で設定されたデフォルト値にリセットされます。 そのため、すべてのリクエストにおいて (そしてsession_start() をコールする前に) session_cache_expire() をコールする必要があります。
パラメータ
- new_cache_expire
-
new_cache_expire が指定された場合、 現在のキャッシュの有効期限は、 new_cache_expire で置換されます。
注意: session.cache_limiterが nocache以外の値にセットされている場合にのみ new_cache_expire が有効となります。
返り値
session.cache_expire の現在の設定を返します。 返り値は分単位で、デフォルトは 180 です。
例
例1 session_cache_expire() の例
<?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";
?>
add a note
User Contributed Notessession_cache_expire
Anonymous
21-Feb-2008 01:50
21-Feb-2008 01:50
info at ericbontenbal dot nl
09-Aug-2006 04:34
09-Aug-2006 04:34
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
21-Nov-2005 10:49
21-Nov-2005 10:49
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 11:21
23-Sep-2005 11:21
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
18-Jun-2005 06:47
18-Jun-2005 06:47
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.
bermiferrer[at]akelos[NOSPAM]com
03-Jun-2004 05:11
03-Jun-2004 05:11
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