php session超时时间_PHP: session_start - Manual

3 easy but vital things about Sessions in AJAX Apps.

//  It is VERY important to include a Period if using

// a whole domain.  (.yourdomain.com)

// It is VERY important to set the root path your session will always

// operate in... (/members) will ensure sessions will NOT be interfered

// with a session with a path of say (/admin) ... so you can log in

// as /admin and as /members... NEVER do unset($_SESSION)

// $_SESSION=array(); is preferred, session_unset();  session_destroy();session_set_cookie_params(0,'/members','.yourdomain.com',0,1);session_start();$_SESSION= array();session_unset();session_destroy();session_set_cookie_params(0,'/members','.yourdomain.com',0,1);session_start();$_SESSION['whatever'] ='youwhat';// session destroying

// To be safe, clear out your $_SESSION array

// Next, what most people do NOT do is delete the session cookie!

// It is easy to delete a cookie by expiring it long before the current time.

// The ONLY WAY to delete a cookie, is to make sure ALL parameters match the

// cookie to be deleted...which is easy to get those params with

// session_get_cookie_params()...

// FInally, use  session_unset(); and session_destroy(); in this order to ensure

// Chrome, IE, Firefox and others, are properly destroying the session.$_SESSION= array();

if (ini_get('session.use_cookies'))

{$p=session_get_cookie_params();setcookie(session_name(),'',time() -31536000,$p['path'],$p['domain'],$p['secure'],$p['httponly']);

}session_unset();session_destroy();// AJAX and SESSIONS.

// Example... you start a session based PHP page, which then calls an Ajax (XMLHTTP) authenticated

// using the SAME SESSION to Poll and output the data, for example.  But, you notice when you

// try to start the Polling AJAX call always HANGS and seems to hang at the session_start().

// This is because the session is opened in the first page, calls the AJAX polling example, and

// tries to open the same session (for authentication) and do the AJAX call, you MUST call

// session_write_close(); meaning you are done writing to the $_SESSION variable, which really

// represents a file that must be CLOSED with session_write_close();....

// THAN you can call your AJAX Polling code to reopen the same session and do its polling...

// Normally, the $_SESSION is closed automatically when the script is closed or finished executing

// So, if you need to keep a PHP page running after opening a SESSION, simply close it when finished

// writing to $_SESSION so the AJAX polling page can authenticate and use the same session in a

// seperate web page...session_write_close();?>

Hope this helps someone with their sessions...

Thanks.