每次页面加载时都会运行PHP登录

Question

Pages involved are:

1. login.php (login forms)
2. admin.php (dashboard)
3. post_ad.php (some random page)

My login pages works fine, then after login comes dashboard, which also works fine!

Problem comes when I go back to admin.php from post_ad.php, using a hyperlink, I redirect to login page! The code actually fails to understand that I have actually logined before correctly! Please help to out to rectify my problem!

admin.php

    include 'connection.php';
    $user = $_POST['user'];
    $pass = $_POST['pass'];

    if($user != 'zxc' && $pass != 'zxc')
    {
        header('Location: login.php');      
    }
    session_start();
    ?>

    <a href="post_ad.php">POST A NEW ADVERTISE</a>

I want the code to remember, untill I logout or close the windows, that I have logined once!

Answer 1

First of all in any page use session_start() at the top of the page not somewhere in middle of code. in login.php File put user id in $_SESSION if user logged in successfully for example

$_SESSION['user_id'] = $user_id

Say $user_id stores username in your code

and at the top of login page use this code

@session_start();
if(isset($_SESSION['user_id']) && $_SESSION['user_id']!='') {
    header("location: admin.php");
}

This will redirect you to admin page if user is logged in and in other pages you could use

@session_start();
if(!isset($_SESSION['user_id']) || $_SESSION['user_id']=='') {
    header("location: login.php");
}

This will redirect you to login page if user is not logged in

Answer 2

You are checking posted variables from login page every time.

Which are not set when navigated from page other than login.

Store the values in sessions instead (on login page action).

$user = $_SESSION['user'];
$pass = $_SESSION['pass'];

And now check these values.

Also, don't forget to include session_start() in the beginning of the page.