Limit direct access to directory using .htaccess

I have the following folder structure where I have a web app running:

/root/public/index.php

I have a .htaccess in the /root that redirects all requests to /root/public but I am also able to access my content by prepending the /public directory in my request for example at the moment I can do

www.example.com/public/index.php
www.example.com/index.php

Both lead to the same resource but I only want people to access the resource by going to and return an error if they try to directly access the /public directory

www.example.com/index.php

My current .htaccesss look like this:

<IfModule mod_rewrite.c>
  RewriteEngine On
  RewriteRule ^(.*)$ public/ [L]
</IfModule>

What am I missing here to stop the accessibility of my /public folder via URLs?

I have tried applying some rewrite rules used by WordPress` but that didn't work for my use-case by following the guide here: https://wordpress.org/documentation/article/htaccess/

Solution

You can do something like this:

RewriteEngine On

# Block direct requests to the "/public" subdirectory
RewriteCond %{ENV:REDIRECT_STATUS} ^$
RewriteRule ^public/ - [F]

# Rewrite all requests to "/public/index.php"
RewriteRule ^ public/index.php [END]

(The <IfModule> wrapper is not required and should be removed.)

The check against the REDIRECT_STATUS environment variable ensures that only direct requests (from the user) are checked and not rewritten requests by the later rewrite.

Note that I changed your existing rule to rewrite the request directly to /public/index.php since that would seem to be the intention. (Rather than relying on the DirectoryIndex.)

Although, I'm wondering how you are managing your static assets (if any)?