RE: [PHP] sessions?

> Just trying to understand sessions. For example, I have a user login page > and a logout page. If 10 people are logged in and three of them log out - > how does session_destroy() know which sessions to kill. I understand there > are session id's - but not sure how they are assigned to each user and how > they are controlled. Now what if I wanted to use another session for a > chatroom lets say, same question as above - how are these controlled. I'm > just trying to further understand how exactly sessions work so that when I > am trying to use them I can do so more efficiently. Sessions are controlled by a 32 character session id that is designed to be unique for each session that's started. When session_start() is encounted, it looks for a session id in the URL or in a cookie. If it does not find one, it creates an ID for the request and puts it in cookie (by default) or in the URL later. If a session ID already exists when session_start() is called, PHP (by default) opens a file on the server related to that unique session id and loads the data from it. At the end of the PHP file, the new/changed session data is saved back to the file. If someone logs out and you use session_destroy(), then the file related to their session ID is destroyed along with the cookie (I think). Now, if they come back, they'll get a new session ID and a new empty file. ---John W. Holmes... PHP Architect - A monthly magazine for PHP Professionals. Get your copy today. http://www.phparch.com/