#!/usr/bin/perl -T
use strict;

package sessionTest;

use Apache::Session::File;
use CGI::Safe qw/ taint :standard :html3 :html4 /;
use CGI::Carp qw/ fatalsToBrowser /;

my $query = CGI::Safe->new;
my $sessionCookie;
my %session;
my $id;
my $sessionID;

my $scriptName = $query->self_url;
$scriptName =~ s/\?.*//;

$sessionCookie = $query->cookie(-name=>'sessionTest');
if (defined($sessionCookie))
{   
    if ($query->url_param('keywords') =~ /logout/)
    {   
        # in here $sessionCookie actually contains the value of the cookie,
        # below it is the whole cookie.
        #
        # This could be done by reusing the $id value, but I think it's a bit
        # clearer here that we're reading a previous session id if we do it
        # this way.
        $sessionCookie =~ /([a-z0-9]+)/;
        $sessionID = $1;
        tie %session, 'Apache::Session::File', $sessionID,
        {   
            Directory       =>  './.sessionDir',
            LockDirectory   =>  './.lockDir'
        };
        tied(%session)->delete;
        untie(%session);
        $sessionCookie = $query->cookie(
            -name=>'sessionTest',
            -value=>"",
            -expires=>'Thu, 31-Dec-1974 00:00:00 GMT'
        );
        print $query->redirect(-uri=>"$scriptName",-cookie=>$sessionCookie);
    }
    else
    {
        # the browser has a session cookie, print out a page that will let us
        # remove it.
        print $query->header();
        print $query->start_html(-title=>"Welcome back");
        print "Your session id is $sessionCookie.";
        print "<a href=\"$scriptName?logout\">click here</a> to log out\n";
        print $query->end_html();
    }
}
else
{
    # the browser doesn't have a session cookie, feed it one.
    tie %session, 'Apache::Session::File', $id,
    {
        Directory       =>  './.sessionDir',
        LockDirectory   =>  './.lockDir'
    };
    $sessionCookie = $query->cookie(
        -name       =>  'sessionTest',
        -value      =>  $session{_session_id},
        -expires    =>  0
    );
    untie(%session);
    print $query->redirect(-uri=>"$scriptName",-cookie=>$sessionCookie);
}