Issues with HEADERS and Server

Server Config
1

I’ve been working on a website for awhile now and everything works perfectly fine on my WAMP environment. Lately, I uploaded it to the production server to discover that nothing works. Ha. Just my luck! :slight_smile:

So it would seem through looking into the markup to figure out what’s up that there’s an apparent header issue. Below is the following “Warning” message that I found:

<b>Warning</b>: Cannot modify header information - headers already sent by (output started at /export/home/account/public_html/user/some_folder/themes/isu_english/header.php:6) in <b>/export/home/user/public_html/some_folder/login.php</b> on line <b>341</b><br />

Knowing what little I know about this right now, it would seem that some changes I made to the login.php file has caused a bit of a rift with the way some redirects are being used. That’s okay because I think I can fix it but it leads me to be curious about my development environment in contrast to the production environment.

My basic question here is about this header issue: what would cause something like this to work perfectly fine in my development environment and break on the production environment? Something with a PHP directive? The versions of Apache and PHP are the same. I didn’t check the MySQL because in my mind, this doesn’t relate to that. I might be wrong, though…

Any ideas would be appreciated. This has me stumped.

2

Presumably the // EOF informs everyone that that is actually the end and no lines have been accidentally lost.

3

The message means something is being output to the web page prior to the headers.

This can be something like a byte order mark added to the front of files, a space before the <?php at the start of any file, or even a prior error message relating to an error earlier in the file.

4

Also, ZenCart is now advertising a “fix” to the spaces after a ?> in an included file:

Regards,

DK

5

few - BOM Removal - tricks:

  1. “edit /77 <yourfile.php>” and delete first illegal characters.
  2. Open the file in notepad and save it as ascii text.

Make sure that header.php does not echo/print anything.
In general do not output anything before setting up cookies, calling sesion_start(), header(), …

in worst case (when there are several files to edit for this fix and you want a quick fix for a debug only purpose, remove Byte Order Mark in header.php and put the first PHP code as:


<?php
ob_start();
...