PHP: Create a simple log in form without MySQL - php

Question

I'm trying to mess around with a simple log in form, that is just for fun. The content is nothing sensitive, but I'm trying to learn SESSION and such. I've created this simple login form, that works fine, but if a user clicks the "home" button which is href'd to process_login.php, they are asked to login again. I'm trying to save the username and password it in a SESSION so if they login, and hit home from any page, it will remember their log in information and not ask them to continuously log in.
I have a form.php script, that uses the POST method, with two textfields, the username and password are saved as "admin" in the process_login.php, and if they match the POST indices from the form, then i'll include content.php. In process_login.php I take the POST data and run it like so :
SESSION_start();
//var_dump($_POST);
$match_username = 'admin' ;
$match_password = 'admin';
if(isset($_POST['submit'])){
$username = $_POST['username'];
$password = $_POST['password'];
if($username == $match_username && $password == $match_password ){
include 'content.php';
}elseif($username == "" || $password != $match_password){
echo "Please try again.";
}
if(!isset($_SESSION["logged_in"])){
//Run if not set
$_SESSION["logged_in"] = array(1 => array($username => $_POST['username'], $password => $_POST['password']));
};
};
You'll see above that I'm trying to set the SESSION information, but I know i'm not doing it correctly. Once a user logs in, everything works. But if that same user clicks on "home," from another page, it will tell them to "Please try again." I'd like to let the user stay logged in once they are logged in.
All advice is appreciated. Thank you!

Answer 1

Your test of $_SESSION["logged_in"] should not be inside the if(isset($_POST['submit'])) block.
if (isset($_SESSION['logged_in'])) {
include 'content.php';
exit();
}
if (isset($_POST['submit'])) {
$username = $_POST['username'];
$password = $_POST['password'];
if($username == $match_username && $password == $match_password ){
$_SESSION["logged_in"] = array('username' => $_POST['username'], 'password => $_POST['password']);
include 'content.php';
exit();
} elseif($username == "" || $password != $match_password){
echo "Please try again.";
}
// Put login form here
I changed your $_SESSION["logged_in"] variable. Now it's just a one-dimensional array instead of 2-dimensional, and the keys are the words username and password -- it doesn't make much sense to use variables as keys there.