Cannot change session id when headers already sent

[dmx1]

Hi Larry,

I put the website online on a hosting server with a few html design alterations.

It works fine up until when I try and get onto the checkout.php page.

It gives me the following error:

'checkout.php' on line 10:
session_id(): Cannot change session id when headers already sent'

I removed all the ?> tags from the all .php files. I have spent two whole days trying to find out what the problem is, but nothing.

The problem occurs when I get to the line

session_id($uid);  on the 'checkout.php' page on page 297.

If I remove the lines:

session_id($uid);

session_start();

in the checkout.php on page 297, I then get access to the 'checkout.php' page.

For some reason, the session_id($uid); and session_start() lines are the problematic lines.

Can you suggest what it could be, and what I could do to fix the problem.

Thank you

regards

 

[dmx1]

Note: For some reason, the lines are getting spaced out

Hi Larry,

I made a slight adjustment in the checkout.php file. I simply moved the session_id($uid) and session_start() lines to the top of the page, and it works. I can now go straight to the checkout.php page without it giving me the error 'session_id(): Cannot change session id when headers already sent'

For example on the checkout.php page I commented out the session_id($uid) and session_start() lines, and just put them right at the start of the checkout.php page on page 297 as follows:

 

<?php

 

session_id($uid);

session_start();

 

require('./includes/config.inc.php');

 

// Check for the user's session ID, to retrieve the cart contents:

if ($_SERVER['REQUEST_METHOD'] === 'GET') {

if (isset($_COOKIE['SESSION']) && (strlen($_COOKIE['SESSION']) === 32)) {

$uid = $_COOKIE['SESSION'];

 

// Use the existing user ID:

//session_id($uid);

// Start the session:

//session_start();

} else { // Redirect the user.

$location = 'http://' . BASE_URL . 'cart.php';

header("Location: $location");

exit();

}

} else { // POST request.

session_start();

$uid = session_id();

}

 

Qu 1: Can I leave it like this, or won't this work?

 

Qu 2: Based on what I just did, what do you think could be the problem?

 

It seems the problem starts after the require('./includes/config.inc.php') line.

 

If I could just simply put the code at the top of the page, this would solve the problem, but I don't know if this is allowed. Also, I would like

to find out why the original code in the checkout.php page stops working and throws out the error message:

session_id(): Cannot change session id when headers already sent'

 

regards

Edited February 6, 2022 by dmx1
Lines are too spaced out

[dmx1]

Hi Larry,

 

I sorted the problem. Please ignore the previous posts.

Thank you!

[Larry]

Kudos for solving it!