How to rewrite specific pages using mod rewrite?

Question

Assuming that my website homepage is https://example.com/test-website/. What I want to do is to add a query string at the end of the homepage URL and on all pages that start with https://example.com/test-website/products/ and https://example.com/test-website/shop/.

This is my current code:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /test-website/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /test-website/index.php [L]

RewriteCond %{REQUEST_METHOD} !^POST
RewriteCond %{QUERY_STRING} !^loc [NC]
RewriteRule (.*) /%{REQUEST_URI}/?loc=%{HTTP:CF-IPCountry} [NC,NE,R,L,QSA]
</IfModule>

# END WordPress

My code works fine and adds the 'loc' query string parameter to the homepage URL and to all pages on wp-admin but it doesn't work on any other pages on the frontend like https://example.com/test-website/products/. The page just opens normally but without the query string.

I tried to remove the following from my code

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /test-website/index.php [L]

This resulted in making the homepage and wp-admin to still work fine but any other pages on the frontend to give 404 error.

Hope you can help me solve this issue, especially that I don't have experience in regex or mod_rewrite.

Answer 1

What you are describing is an (external) redirect, not an (internal) "rewrite" as stated in your question title. (If you wanted a "rewrite" then you would not use .htaccess for this on a WordPress site.)

Also, you shouldn't be modifying the WordPress directives inside the # BEGIN WordPress code block - this is managed by WordPress and is likely to be overridden when WP updates (or at least it will try to).

I tried to remove the following from my code

The code you are trying to remove is part of the WordPress front-controller. If you remove that then pretty permalinks will not work and your site will likely break. (ie. Pages in the frontend won't resolve and you'll get a 404.)

You've basically put your redirect directives in the wrong place. By placing them after the WP front-controller they simply won't get processed for any "frontend" URLs (except for the homepage, which isn't caught by the preceding front-controller on the first pass). They need to go before the # BEGIN WordPress block near the top of your .htaccess file.

However, your directives are not specifically checking the URL-paths you want to redirect. ie. the homepage, /test-website/products/ and /test-website/shop/. Your generic regex .* matches everything!?

Assuming your .htaccess is located in the /test-website subdirectory then try the following instead:

RewriteCond %{REQUEST_METHOD} !^POST
RewriteCond %{QUERY_STRING} !^loc [NC]
RewriteRule ^($|products/|shop/) /%{REQUEST_URI}/?loc=%{HTTP:CF-IPCountry} [NC,NE,R,L,QSA]

# BEGIN WordPress
:

Aside: Do you really want to unconditionally append a trailing slash to the URL-path?