PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

516 Chapter 23 Using Session Control in PHP
As you can see in Figure 23.3, you no longer have access to the persistent value of
$_SESSION[‘sess_var’].
Figure 23.3
The session variable is no longer available.
With some PHP versions prior to 4.3, you might encounter a bug when trying to unset
elements of $HTTP_SESSION_VARS or $_SESSION. If you find that you are unable to unset
elements (that is, they stay set), you can revert to using session_unregister() to clear
these variables.
You finish by calling session_destroy() to dispose of the session ID.
Configuring Session Control
There is a set of configuration options for sessions that you can set in your php.ini file.
Some of the more useful options, and a description of each, are shown in Table 23.1.
Table 23.1 Session Configuration Options
Option Name Default Effect
session.auto_start 0 (disabled) Automatically starts sessions.
session.cache_expire 180 Sets time-to-live for cached session pages, in
minutes.
session.cookie_domain none Specifies the domain to set in the session
cookie.
session.cookie_lifetime 0 Sets how long the session ID cookie will
last on the user’s machine.The default, 0,
will last until the browser is closed.
session.cookie_path / Specifies the path to set in the session
cookie.