Remotely destroy a session in php (user logs in somewhere else)?

php session logout
twistedpixel picture twistedpixel · Mar 26, 2011 · Viewed 13k times · Source

Hey, I'm trying to get my php website to basically "log out" (session_destroy()) when the same user logs in somewhere else. Is there a way to do this? To remotely destroy a specific session?

Thank guys!

Scott

Answer

Jon picture Jon · Mar 26, 2011

It's certainly possible, using session_id. When the user logs in somewhere else, you can do this step before starting a new session for the new login:

// The hard part: find out what $old_session_id is

session_id($old_session_id);
session_start();
session_destroy();

// Now proceed to create a new session for the new login

This will destroy the old session on the server side, so when the other computer accesses your application again it will try to access a non-existent session and a new one will be created for it (in which the user is not logged in anymore).

The hard part is finding out what is the ID of the "old" session. There's no one-size-fits-all way of doing that; you need to have some mechanism in place to be able to tell that the session with id XXX belongs to the same user who is logging in now. If you are using database sessions this should be easy enough.

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