Question

I have a domain oldexample.com, and I want to redirect users who visit that domain to newexample.com only when no parameters are given. In the case where parameters are supplied with the domain, it should redirect elsewhere – so, oldexample.com/?id=5 should not redirect to newexample.com, rather I want to redirect it to some internal directory in newexample.com, say to newexample.com/dir/5.

Here’s a summary of how I want the redirects to work:

oldexample.com -> newexample.com
oldexample.com/?id=3 -> newexample.com/dir/3
oldexample.com/index.php?id=6 -> newexample.com/dir/6

So how would I write the RewriteRules in htaccess to get this job done?

Answer 1

Try:

RewriteEngine On

# for /
RewriteCond %{HTTP_HOST} ^oldexample.com$ [NC]
RewriteCond %{QUERY_STRING} !id=
RewriteRule ^$ http://newexample.com/ [L,R=301]

# for /?id=###
RewriteCond %{HTTP_HOST} ^oldexample.com$ [NC]
RewriteCond %{QUERY_STRING} ^id=([0-9]+)
RewriteRule ^(index.php)?$ http://newexample.com/dir/%1? [L,R=301]

The last rule matches against / and /index.php. These rules need to be in the htaccess file in your oldexampl.com document root.