regex to not match if a specified string exists

Question

i'm trying to do an apache rewrite where if the term "admin" is contained in the request_uri

mydomain.com/admin/anything_else

re-write the host to use a subdomain

admin.mydomain.com/admin/anything_else.

likewise, if i click a link while in the admin.mydomain.com and it is a url WITHOUT "admin" in it, then i would like to rewrite the url back to

mydomain.com/anything_else

My question is. can regex do an exist check like that? I'm aware that it can do terms not matching (I don't know the syntax though...), but in this case I want regex to fail completely. Any ideas?

ReWriteCond [^(admin)]$

mydomain.com/admin/hi - matches mydomain.com/anything - doesn't match

Answer 1

You may try using negative lookaheads, like mydomain.com/(?!admin)

Answer 2

Try these rules:

RewriteCond %{HTTP_HOST} !=admin.example.com
RewriteRule ^admin(/|$) http://admin.example.com%{REQUEST_URI} [L,R=301]
RewriteCond %{HTTP_HOST} =admin.example.com
RewriteRule !^admin(/|$) http://example.com%{REQUEST_URI} [L,R=301]

Answer 3

I ended up doing something similar...

# Redirect to subdomain admin for an admin specific uri request
RewriteCond %{HTTP_HOST} ^www.example.com$
RewriteCond %{REQUEST_URI} admin
RewriteRule ^(.*)$ http://admin.example.com$1 [L]

# Redirect to subdomain admin for an admin specific uri request
RewriteCond %{HTTP_HOST} ^admin.example.com$
RewriteCond %{REQUEST_URI} !admin 
RewriteRule ^(.*)$ http://www.example.com$1 [L]