PHP & .htaccess redirection loop [does header(location: url) consult .htaccess?]

Question

I'm currently forwarding all requests to a single .php file:

Options +FollowSymLinks
Options -Multiviews
Options All -Indexes

RewriteEngine On
RewriteRule ^(.*)$ urls.php [L,QSA]

For simplicity, lets say the urls.php page is as follows:

<?php
    if(condition) {
        header( "Location: index.php" );
    } else {
        header( "Location: somewhere.php" );
    }
    die();
?>

When a request is made, it enters a redirect loop, I assume this is because it's a never ending loop from urls.php to the page it redirects to and back again.

Questions:
-> Does the header() function always consult the .htaccess file, or is there a way to skip it and go directly to the url?
-> If it always consults it, is there a different PHP approach that I could use to achieve what I want?

Answer 1

Instead of redirect you should you should extract url and route accordingly by using 'include' function. You can apply your logic before routing.

Answer 2

Every HTTP request makes the server read the .htaccess file.

To answer your questions:

1. Yes, header() outputs an HTTP 301 header which generates another request.
2. SOLUTION is to include() the corresponding page instead of redirecting to it using header() .

Note:
As @goldlife pointed out in a comment, your rule and page together generate a loop because:

1. url.php redirects to index.php using the header() function
2. index.php , in turn, is rewritten by your .htaccess to url.php

To break this loop, you should drop one of the two operations (I vote for dropping the first one).