.htaccess RewriteRule to path without changing URL - regex

Question

So, I've this problem:
Base Website located at http://example.com/
Second Website located at http://example.com/web2/
People making various requests to the second website like
http://example.com/myWeb/pg1 and http://example.com/web2/pg2
Recently and due to some other issues I need to have a custom new path for the second website but also keep the first one working.
The ideia is to allow users to access the second website over the two following addresses:
http://example.com/web2/
http://example.com/alternative-url-web2/
The folder /web2/ actually exists on the server, but how can I simulate the folder /alternative-url-web2/ and "redirect" the requests to /web2/?
Please note I don't want the URL on the browser to change, this must be a "silent redirect". And I also make sure that all other requests like http://example.com/other are not redirected by the second website.
Thank you.
Update:
According to #anubhava I could simply solve this issue by adding in my .htaccess:
Options +FollowSymLinks -MultiViews
RewriteEngine On
RewriteBase /
RewriteRule ^alternative-url-web2(/.*|)$ /web2$1 [L,NC]
This is probably working fine but I noticed the following:
http://ex.com/alternative-url-web2 is redirected to http://ex.com/web2/ (changing browser URL);
http://ex.com/alternative-url-web2/ is redirected to http://ex.com/(changing browser URL);
http://ex.com/alternative-url-web2/someRequest works fine and does NOT change the browser URL;
http://ex.com/alternative-url-web2/index.php works fine and does NOT change the browser URL;
Site Note:
At /web2/ there's an .htaccess that might be cause the wired redirect behavior above... So here is the file contents:
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]
RewriteRule ^(data/|js/|styles/|install/|favicon\.ico|crossdomain\.xml|robots\.txt) - [NC,L]
RewriteRule ^.*$ index.php [NC,L]
</IfModule>
Can the internal RewriteRule to index.php be causing all this? If yes, how can I fix it?

Answer 1

Enable mod_rewrite and .htaccess through httpd.conf and then put this code in your .htaccess under DOCUMENT_ROOT directory:
Options +FollowSymLinks -MultiViews
# Turn mod_rewrite on
RewriteEngine On
RewriteBase /
RewriteRule ^alternative-url-web2(/.*|)$ /web2$1 [L,NC]
Alternate code:
RewriteRule ^alternative-url-web2/?$ /web2/ [L,NC]
RewriteRule ^alternative-url-web2/(.+)$ /web2/$1 [L,NC]

Answer 2

This is a pretty simple rewrite. In the htaccess file in your document root, just add the following:
RewriteEngine On
RewriteRule ^alternative-url-web2/?(.*)$ /web2/$1 [L]
Unlike a redirect, which makes the browser/client send a new request for a new URL (thus changing what's in the browser's location bar), a rewrite happens entirely on the server's side.

Answer 3

By the way, in order to follow the trail of htaccess redirects, you could add something like this to each of them:
Header add X-Remark-Rewrite "/path.to/htaccess"
You can inspect these in the response in the developer tools.