session_start() error always redirect to login.php
Question
Login (login.php) page works fine but it redirects to the index.php page
login.php
<?php
ob_start();
session_start(); ?>
<html>
<head>
<meta charset="utf-8">
<form method="post" action="login.php" >
<div class="form-group" >
<input type="text" class="form-control" name="user_name" >
</div>
<div class="form-group">
<input type="password" class="form-control" name="user_pass" >
</div>
<input type="submit" name="login" value="Login" >
</form>
</body>
</html>
<?php
include '../includes/connection.php'; /* connection query */
if (isset($_POST['login'])) {
$username = $_POST['user_name'];
$userpass = $_POST['user_pass'];
$admin_query = "select * from admin_login where user_name = '$username' AND user_pass = '$userpass'";
$run = mysql_query($admin_query);
$rows = mysql_num_rows($run);
if ($rows == 1) {
$_SESSION['login_user']=$username;
header("location: index.php");
} else {
echo "<script>alert('User name of password is incorrect')</script>";
}
}
?>
In index page (index.php), session has error and always redirects to login.php
index.php
<?php
session_start();
if(!isset($_SESSION['login_user'])){
header('Location: login.php');
}
else
{
?>
<!doctype html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<div class="row cms-admin-panel">
<div class="col-md-12 "><h5> Welcome: <?php echo $_SESSION['login_user'] ?> </h5> <a href="logout.php">logout</a>
<h4 align="center">CMS Admin Panel</h4>
</div>
</div>
</body>
</html>
<?php } ?>
Logout page working fine, it redirect to the login.php page.
logout.php
<?php
session_start();
session_destroy();
header("location: login.php");
?>
2 answers
solution1
1 2016-06-13 17:31:26
Move the session_start(); before the <form> .
The session_start() function must be the very first thing in your document. Before any HTML tags.
Where exactly do I put a SESSION_START?
Long answer:
Since sessions are handles by cookies by default,
To use cookie-based sessions, session_start() must be called before outputing anything to the browser.
solution2
0 2016-06-13 19:12:05
First of all, your session_start() should be at the very top of the page. Secondly, if you ever have some kind of situation where you have more than one session_start() in a page, always check if session is started already or not as,
if(session_status() == PHP_SESSION_NONE) {
session_start();
}
Third reason, if header are already sent or some kind of session cache limiter error, you can fix that by output buffer started at the top of page as
ob_start();
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