Yes the same titles and URL's for all 6 multisite domains.
Oh, wait. Wasn't there a similar question just a few days ago? I think that one only involved two domains. But the principle was that
www.example.com/foobar.html >> www.example.com/widget.html
AND
www.example.org/foobar.html >> www.example.org/widget.html
That is, the path part of the redirect was the same, but each had to stay in its own domain. And you can't just cheat by using /widget.html as the target, because that won't get your domain name into canonical form.
Is that what you've got here? Or will
www.example.com/foobar.html
AND
www.example.org/foobar.html
each be redirected to a
different filename?
If so, I don't see much alternative to having every single one of your 600 redirects come with a preceding Condition checking for domain, like
RewriteCond %{HTTP_HOST} example\.org
RewriteRule widget\.html http://www.example.org/pageone.html [R=301,L]
RewriteCond %{HTTP_HOST} example\.com
RewriteRule widget\.html http://www.example.com/pagetwo.html [R=301,L]
and so on. A new one for each Rule, because Conditions belong to one rule.
It would be good to have dynamic htaccess files for each of the six websites but I dont think this is possible...
What do you mean by "dynamic" and why isn't it possible? It's true that in general you want to put your rules as high up the (physical) filepath as possible-- but this isn't "in general". Here I think you would save a lot of time and resources if everything domain-specific went in the htaccess for that domain alone. For starters, you'd be able to throw away 600 lines of identical RewriteCond.
You can't put <Directory> envelopes in an htaccess. You
might be able to do something with FilesMatch, but frankly I've never got it to behave properly when matching anywhere but the far right (end of name).
