Untitled

//admin.php
-------------------------------------------
<?php
// Memeriksa apakah pengguna sudah login atau belum
session_start();
if (!isset($_SESSION['username'])) {
  header('Location: /act5/no3/index.php'); // Jika belum login, redirect ke halaman login
  exit;
}
?>

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Faris Rasyid | 50421483</title>
</head>

<body>
  <h1>Selamat datang, <?php echo $_SESSION['username']; ?></h1>
  <p>Ini adalah halaman admin.</p>

  <a href="logout.php">Logout</a>
</body>

</html>

------------------------------------------------------------------
login.php
-------------------------------------------------------------------
<?php
// Simpan informasi login di sini
$valid_username = 'faris';
$valid_password = 'admin';

session_start();

// Mengecek apakah ada data yang dikirim melalui metode POST
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $username = $_POST['username'];
  $password = $_POST['password'];

  if ($username == $valid_username && $password == $valid_password) {
    $_SESSION['username'] = $username;

    header('Location: /act5/no3/admin.php');
    exit;
  } else {
    $_SESSION['error_message'] = 'Username atau password salah';

    header('Location: /act5/no3/index.php');
    exit;
  }
}
------------------------------------------------------------------
index,php
-----------------------------------------------------------------
<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Faris Rasyid | 50421483</title>
</head>

<body>
  <h1>Halaman Login</h1>

  <?php
  session_start();
  if (isset($_SESSION['error_message'])) {
    echo '<p style="color: red;">' . $_SESSION['error_message'] . '</p>';
    unset($_SESSION['error_message']); // Menghapus pesan error setelah ditampilkan
  }
  ?>

  <form action="login.php" method="POST">
    <label for="username">Username:</label>
    <input type="text" id="username" name="username" required><br><br>

    <label for="password">Password:</label>
    <input type="password" id="password" name="password" required><br><br>

    <input type="submit" value="Login">
  </form>
</body>

</html>
----------------------------------------------------------------------------
logout.php
----------------------------------------------------------------------------
<?php
session_start();

// Hapus sesi username
unset($_SESSION['username']);

// Redirect ke halaman login
header('Location: /act5/no3/index.php');
exit;