htaccess - canonical URL when redirecting to subdirectory - apache

Question

I've been playing around with this problem for quite a while but can't find the way how to achieve what I want. I want user coming to my website test.com to reach index.php located in subdirectory www immediatelly, which I am able to do. But when the URL is test.com/www I want it to be just test.com.
Snippets of code:
.htaccess in /
RewriteRule ^(.*)$ /www/$1 [L]
.htaccess in /www
RewriteCond %{REQUEST_URI} ^/www.*$
RewriteRule ^/www/(.*)$ /$1 [L]
gives me 500 Internal Error.
UPDATE:
I came to a solution thanks to #Justin Iurman's answer:
.htaccess in /www
RewriteCond %{THE_REQUEST} \ /www/?(.*)\ HTTP/ [NC]
RewriteRule ^(.*)$ /%1 [R=301,L]
Have another problem tho. On the server machine I have multiple websites and I want to serve files according to HTTP_HOST variable in root .htaccess file. I redirect user accessing test.com to proper directory (say test), but I want URL test.com/test to redirect just to test.com. Directory test contains directory www where user is redirected and it does not stick to URL thanks to solution above. I would like to edit just .htaccess file in webserver root so I don't have any dependancy on websites' domains in projects.
SOLVED
.htaccess in webserver root:
<IfModule mod_rewrite.c>
RewriteEngine On
# Redirect test.com/test (and everything into test folder) to test.com root
RewriteCond %{HTTP_HOST} ^test\.com$ [NC]
RewriteCond %{THE_REQUEST} \ /test/? [NC]
RewriteRule ^.*$ / [R=301,L]
# Forward (internally rewrite) test.com/one/example/page to test.com/test/www/one/example/page
RewriteCond %{HTTP_HOST} ^test\.com$ [NC]
RewriteRule ^(.*)$ /test/www/$1 [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
</IfModule>
.htaccess in the "test" directory:
<IfModule mod_rewrite.c>
RewriteEngine On
# allow /test in URL only for certain filetypes
RewriteRule ^(.*\.(pdf|js|ico|gif|jpg|png|css|rar|zip|tar\.gz))$ /test/www/$1 [L]
# allow /test on localhost
RewriteCond %{HTTP_HOST} ^localhost$ [NC]
RewriteRule ^(.*)$ /test/www/$1 [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
</IfModule>
Thanks a lot Justin!

Answer 1

You have to avoid infinite loop when doing what you want.
Put this code in your htaccess
RewriteEngine on
RewriteCond %{THE_REQUEST} \ /www/?(.*)\ HTTP/ [NC]
RewriteRule . /%1 [R=301,L]
RewriteRule ^(.*)$ /www/$1 [L]
EDIT: taking your update into consideration, here's the new code
RewriteEngine on
# Redirect test.com/test (and everything into test folder) to test.com root
RewriteCond %{HTTP_HOST} ^test.com$ [NC]
RewriteCond %{THE_REQUEST} \ /test/? [NC]
RewriteRule . / [R=301,L]
# Forward (internally rewrite) test.com/one/example/page to test.com/test/www/one/example/page
RewriteCond %{HTTP_HOST} ^test.com$ [NC]
RewriteRule ^(.*)$ /test/www/$1 [L]