.htaccess redirect but keep url - .htaccess

Question

I have the following code and I am trying to do something like that. Let's say I have an address - mydomain.com/server2/ when I type anything after slash for example mydomain.com/server2/whatever I want to load server2.php but address has to be the same
<IfModule mod_rewrite.c>
Options +FollowSymlinks
# Options +SymLinksIfOwnerMatch
RewriteEngine On
RewriteBase /
# remove index.php
RewriteRule ^index\.php/?$ / [L,R=301,NC]
# Hide File Extensions
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^([^/]+)/$ $1.php
# Add 301 redirects to new extensionless file
RewriteCond %{THE_REQUEST} ^[A-Z]+\ /([^/]+/)*[^.]+\.php(\?[^\ ]*)?\ HTTP/
RewriteRule ^(([^/]+/)*[^.]+)\.php$ http://www.mydomain.com/$1 [R=301,L]
# Add the trailing slash
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !(\.[a-zA-Z0-9]{1,5}|/)$
RewriteRule (.*)$ http://www.mydomain.com/$1/ [R=301,L]
</IfModule>
also I don't know if above code is 100% correct. Thanks for any help.

Answer 1

There are problems in your code and in certain URLs it will give you infinite looping. Replace your code with this:
<IfModule mod_rewrite.c>
Options +FollowSymlinks
RewriteEngine On
RewriteBase /
# remove index.php
RewriteCond %{THE_REQUEST} /index\.php [NC]
RewriteRule ^(.*?)index\.php$ /$1 [L,R=301,NC,NE]
# To externally redirect /dir/foo.php to /dir/foo
RewriteCond %{THE_REQUEST} ^[A-Z]{3,}\s/+(.+?)\.php[\s?] [NC]
RewriteRule ^ /%1/ [R=301,L,NE]
# To internally forward /dir/foo to /dir/foo.php
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{DOCUMENT_ROOT}/$1.php -f
RewriteRule ^(.+?)/?$ /$1.php [L]
# Add the trailing slash
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule [^/]$ %{REQUEST_URI}/ [L,R=301]
</IfModule>