How can I redirect in PHP with this setup below without getting header output errors, I understand that nothing can be printed to the browser before a header is set, I am lookin
As long as you have no script output before the header() function you should be fine. Check there are no echo's or whitespace. Also putting ob_start() at the beginning can help. sometimes there is invisible whitespace - changing the format of your document to ANSI or Unicode may help!
As a note (although I think you already know) header does not terminate the script so the exit() (which you have) is a definite requirement.
use { echo '<META HTTP-EQUIV="Refresh" Content="0; URL=process.php">';}
Use ob_start() in the first line even befor the include. so you can set headers anytime.
Does the footer.inc.php and SOME-FILE-HERE.php write to the response stream immediately? Because if so, this won't work as you will have already written something before you sent the headers.
As already mentioned by the others use ob_start() or the output_buffer-setting to buffer the output. Apart from that it's from my point of view not a good practice to output content in the middle of functional code but this is a another topic.
You can find more information at Google or in this Article about Output Buffering in PHP.
You need to buffer the ouput so that the HTTP header is not send on the first output. You can either buffer any ouput implicitly by enabling ouput_buffering or explicitly by calling ob_start. But the latter has to be called before the first output, so ideally in the first line of the script that’s initially called.