PHP Tutorial 12

Logging the User In Out:

Index.php

<?php

require 'core.inc.php';

require 'connect.inc.php';

if (loggedin()) {

            echo 'You\'re logged in.<a href="logout.php">Log out</a>';

} else {

                        include 'loginform.inc.php';    

}

?>

Loginform.inc.php

<?php

if(isset($_POST['username']) && isset($_POST['password'])){

            $username=$_POST['username'];

            $password=$_POST['password'];

            $password2 = md5($password);

            if(!empty($username) && !empty($password)){

                        $query="SELECT id FROM users WHERE username='".$username."' AND password='".$password2."'";

                       

                        if($query_run = mysqli_query($mysql_conn,$query)){

                                    $query_num_rows=mysqli_num_rows($query_run);

                                    if($query_num_rows==0){

                                                echo 'Invalid username/password combination.';

                                    } else if($query_num_rows==1) {

                                                // echo 'OK';

                                      $user_id=mysqli_fetch_array($query_run);

                                       extract($user_id);

                                       $_SESSION['user_id']=$user_id;

                                       header('Location: Tutorial2.php');

                                    }

                        }

            } else {

                        echo 'You must supply a username and password';

            }

}

?>

<form action="<?php echo $current_file; ?>" method="POST">

Username: <input type="text" name="username"><br><br>

Password: <input type="password" name="password"><br>

<input type="submit" value="Log in">

</form>

Core.inc.php

<?php

ob_start();

session_start();

$current_file = $_SERVER['SCRIPT_NAME'];

@$http_referer = $_SERVER['HTTP_REFERER'];

function loggedin(){

                if(isset($_SESSION['user_id']) && !empty($_SESSION['user_id']))

                                return true;

                return false;

}

?>

Logout.php

<?php

require 'core.inc.php';

session_destroy();

header('Location: '.$http_referer);

?>