Do you mean redirect to, or do you want a URL rewrite instead?

There is a world of difference in the end result.

.

I assume that you will want to redirect (www.)site.com/folder to subdomain.site.com to eliminate duplicate content first.

After that, I assume a rewrite from subdomain.site.com to site.com/folder/ will be required.

If that is the case, the question was asked several times in recent days, several recent threads have the answer you require.

what i have now is

RewriteEngine on
#
# Internally rewrite "translation-service" subdomain to /translation-services subdirectory
RewriteCond $1 !^translation-service/
RewriteCond %{HTTP_HOST} ^translation-service\.domain\.com
RewriteRule (.*) http://www.example.com/translation-services/$1 [L]
#

i assume this is a rewrite? It works except that the name in the browser changes. But it does its job.

Could you be so kind and explain what the difference would be in a redirect?

[edited by: jdMorgan at 10:36 pm (utc) on July 25, 2007]
[edit reason] example.com [/edit]

> the name in the browser changes

It's an external redirect, because you included "http://example.com" in the substitution URL. Because you did not specify otherwise, it will be a 302-Found (Temporary) redirect.

Coded properly, it would be something like:

# Internally rewrite "translation-service" subdomain to /translation-services subdirectory
RewriteCond $1!^translation-service/
RewriteCond %{HTTP_HOST} ^translation-service\.example\.com
RewriteRule (.*) /translation-service/$1 [L]

For the sake of future growth, I strongly suggest that you name your subdirectory the same as your subdomain (as shown). This will allow expansion to an unlimited number of subdomains using only one rule in the future.

For example:

# Internally rewrite <subdomain>.example.com/<URLpath> to example.com/subs/<subdomain/<URLpath>
RewriteCond $1 !^subs/
RewriteCond %{HTTP_HOST} !^www\.example\.com
RewriteCond %{HTTP_HOST} ^([^.]+)\.example\.com
RewriteRule (.*) /subs/%1/$1 [L]

-or-

# Internally rewrite <subdomain>.example.com/<URLpath> to example.com/<subdomain/<URLpath>
RewriteCond %{ENV:Rewrite-Done} !^Yes$
RewriteCond %{HTTP_HOST} !^www\.example\.com
RewriteCond %{HTTP_HOST} ^([^.]+)\.example\.com
RewriteRule (.*) /%1/$1 [E=Rewrite-Done:Yes,L]

In both cases, a mechanism is required (and present in the code) to prevent an 'infinite' rewriting loop.

If you use the first method, then you can easily externally redirect direct client requests for the subdomain-subdirectories back to the subdomain to avoid duplicate content:

# Externally redirect client requests for example.com/subs/<subdomain>/<URLpath> to <subdomain>.example.com/<URLpath>
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /subs/
RewriteRule ^subs/([^/]+)/(.*)$ http://$1.example.com/$2 [R=301,L]

Jim

[edited by: jdMorgan at 10:02 pm (utc) on Mar. 13, 2009]