Q:

close the loop in .htaccess for redirecting all subfolders to root

I am trying to redirect all subfolders to the root page using .htaccess.  i.e. I'd like to redirect example.com/audio, example.com/video, example.com/images to example.com using below settings: However, I'd like to make it independent from the domain name.  Hence, you don't see 'example.com' in my .htaccess setting. 
RewriteEngine On
RewriteRule  ^([^/]+)(.*)$  / [R]

When I test it, my browser gives me "redirected you too many times error message" error message.  I have checked the apache logs and it shows that the request has been redirected so many times.  I assume when htaccess redirects us to the root the above lines in .htaccess get run again and therefore it makes a loop.  Is there any way I can force htaccess to redirect only those URL with subdirectory ? 

A:

You can try this rule:
RewriteEngine on
RewriteBase /
RewriteCond %{REQUEST_URI} ! ^/$
RewriteRule ^.+$ / [R=301]

With this rule, everything will be redirected to the root except the root itself.