Step 11: Creating the login.functions.inc.php file

Step 11: Creating the login.functions.inc.php file
This file will contain the login functions

file: login.functions.inc.php

<?php
 #### Login Functions #####
 function isLoggedIn()
{
 
        if (session_is_registered('loginid') && session_is_registered('username'))
        {
                return true; // the user is loged in
        } else
        {
                return false; // not logged in
        }
 
        return false;
 }
 function checkLogin($u, $p)
{
global $seed; // global because $seed is declared in the header.php file
 
        if (!valid_username($u) || !valid_password($p) || !user_exists($u))
        {
                return false; // the name was not valid, or the password, or the username did not exist
        }
 
        //Now let us look for the user in the database.
        $query = sprintf("
                SELECT loginid
                FROM login
                WHERE
                username = '%s' AND password = '%s'
                AND disabled = 0 AND activated = 1
                LIMIT 1;", mysql_real_escape_string($u), mysql_real_escape_string(sha1($p . $seed)));
        $result = mysql_query($query);
        // If the database returns a 0 as result we know the login information is incorrect.
        // If the database returns a 1 as result we know  the login was correct and we proceed.
        // If the database returns a result > 1 there are multple users
        // with the same username and password, so the login will fail.
        if (mysql_num_rows($result) != 1)
        {
                return false;
        } else
        {
                // Login was successfull
                $row = mysql_fetch_array($result);
                // Save the user ID for use later
                $_SESSION['loginid'] = $row['loginid'];
                // Save the username for use later
                $_SESSION['username'] = $u;
                // Now we show the userbox
                return true;
        }
        return false;
}
 ?>