(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
session_cache_expire — 返回/设置当前缓存的到期时间
$value = null): int|false
session_cache_expire() 返回
session.cache_expire 的设定值。
请求开始的时候，缓存到期时间会被重置为 180，并且保存在 session.cache_expire 配置项中。 因此，针对每个请求，需要在 session_start() 函数调用之前 调用 session_cache_expire() 来设置缓存到期时间。
value
如果指定 value 且不为 null，就使用
value 的值替换当前缓存到期时间。
注意: 仅在
session.cache_limiter的设置值 不是nocache的时候， 才可以设置value参数。
返回 session.cache_expire 的当前设置值，
以分钟为单位，默认值是 180 （分钟）。如果更改值失败，则返回 false。
| 版本 | 说明 |
|---|---|
| 8.0.0 |
value 现在可以为 null。
|
示例 #1 session_cache_expire() 示例
<?php
/* 设置缓存限制为 “private” */
session_cache_limiter('private');
$cache_limiter = session_cache_limiter();
/* 设置缓存过期时间为 30 分钟 */
session_cache_expire(30);
$cache_expire = session_cache_expire();
/* 开始会话 */
session_start();
echo "The cache limiter is now set to $cache_limiter<br />";
echo "The cached session pages expire after $cache_expire minutes";
?>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.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.Just to make things clear. If session.cache_limiter is set to private the following header will be sent in HTTP response:
Cache-Control private, max-age=10800, pre-check=10800
Where 10800 is the amount of seconds - default value of 180 minutes set by session.cache_expire which you are enabled to change with session_cache_expire() on run-time