How to create a session in PHP? How to set a value and remove data from a session?

Question

I am trying to figure out if I can run my sessionpersistence script that I run with Apache to see if sessions persist between two tomcat sites on two separate servers. The load balancer has session persistence enabled but Iam unsure how to test it. My thought was that I would just add the following php script to check, but apparently I am doing something wrong. The script is this:

but it seems not to like it if I add it from the webapps directory or from inside a directory under that. Is there some special trick to running php from inside tomcat ? I have tomcat set up the same on both servers and am fronting it with Apache if that adds options for me.

Answer 1

$_SESSION is a special array used to store information across the page requests a user makes during his visit to your website or web application.

Starting a Session and Storing a value in Session
Before you can to store information in a session, you have to start PHP’s session handling. To start the session session_start() is used -

<?php
// start them engines!
session_start();
// store session data
$_SESSION["username"] = "QueryHome";

session_start() starts the session between the user and the server, and allows values stored in $_SESSION to be accessible in other scripts later on.

Retrieving a Session Variable
You call session_start() again which continues the session in another file and you can then retrieve values from $_SESSION.

<?php
// continue the session
session_start();
// retrieve session data
echo "Username = " . $_SESSION["username"];

Ending a Session Variable
To delete a single session value, you use the unset() function:

<?php
session_start();
// delete the username value
unset($_SESSION["username"]);

Ending all the session variable
To unset all of the session’s values, you can use the session_unset() function:

<?php
session_start();
// delete all session values
session_unset();