How do i know what unixtime a php session will expire?

How do I know how many seconds it will be until a php session expires?

I'm building a web application where users might spend a lot of time typing into big text fields, but for security reasons I still want sessions to time out after 开发者_高级运维a reasonably short period. I want to warn them if their session is about to expire so they can save or take some other action to keep it alive.

Any tips? thanks!

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that's very easy. you have always session timeout left, which is 1440 seconds by default. to get actual value you can use

$seconds=ini_get('session.gc_maxlifetime');

but there is another way, better one. if your application get a text after session expired, save this text into session, ask for the password, and then save the text as if it was the regular submit.

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You can store the expiration time in the database and then display an alert when that is about to happen. Or you could store the expiration time in a cookie value, and then have javascript that constantly checks to see if the session is about to expire.