delete session file

new_gist_file.php

<?php
session_start(); // start the current/old session (loads the $_SESSION variables)
$base_name = '/sess_'; // the base name for the session data files
$old_sessionid = session_id(); // get the current/old id

$_SESSION['test'] = 123; // some test data

session_regenerate_id(); // generate a new id and a new data file

$new_sessionid = session_id(); // get the new session id to store in the user table for the current visitor

session_write_close(); // close (release) the old (and the new) session data file (php apparently doesn't close the old file when the id is regenerated)
unlink('c:' . ini_get('session.save_path') . $base_name . $old_sessionid); // delete the old session data file

session_start(); // restart the current/new session

// show the old/new session id
echo "Old Session: $old_sessionid<br />";
echo "New Session: $new_sessionid<br />";

print_r($_SESSION); // dump any session data
?>