Using session_name() in PHP - Cannot Access Data

问题:

When I use:

session_name( 'fObj' );
session_start();
$_SESSION['foo'] = 'bar';

Subsequently loading the page and running:

session_start();
print_r( $_SESSION );

doe not return the session data.

If I remove the session_name(); it works fine.

Does anyone know how to use sessions with a different session name?

UPDATE:

If I run the above code, as two page loads, and then change to:

session_name( 'fObj' );
session_start();
print_r( $_SESSION );

I can access the data. However, if it will only work if I first load the page without the line:

session_name( 'fObj' );

回答1:

John Robertson is correct, the statement he mentioned comes straight from the PHP manual (http://php.net/manual/en/function.session-name.php).

Your session name by default comes from the php.ini variable 'session.name', and this is generally set to 'PHPSESSID'. At each startup request time (as already mentioned) the session will be renamed to PHPSESSID unless you call session_name( 'fObj') before session_start() on every page, so page1:

<?php
  session_name( 'fObj' );
  session_start();

  $_SESSION['foo'] = 'bar';

page 2:

<?php
  session_name( 'fObj' );
  session_start();

  print_r($_SESSION);

Subsequently you can go to your php.ini settings and change the session.name variable from PHPSESSID to fObj and all of your created sessions will have a session name of fObj.

回答2:

I am able to get it working fine and returning SESSION data with the following code:

session_name( 'fObj' );
$_SESSION['foo'] = 'bar';

session_start();
print_r( $_SESSION );

If I run it with the second session_start(); It comes back with an error telling me a session is already started. If you are in dev, make sure to enable ERROR_ALL in php.ini. Make sure to turn it back off in production. A link to the php error reporting functions.

Update: Also works with: session_name( 'fObj' ); $_SESSION['foo'] = 'bar';

print_r( $_SESSION );

Using Ubuntu 14.04 LTS, PHP 5.5.9-1 (let me know if you need more system info to suss out the problem)

回答3:

In light of nwolybug's post I think this must be due to some environmental settings. I can get this to work via doing the following:

if( $_COOKIE['fObj'] )
{
    session_id( $_COOKIE['fObj'] );
    session_start();
}
var_dump( $_SESSION );