Redirect one subdomain page to a domain page

Question

I want to redirect my subdomain registration page to my domain registration page in .htaccess for wordpress multisite. I am using the below code but it does not work.

//301 Redirect Entire Directory
RedirectMatch 301 http://sub.domain.com/register/(.*) http://domain.com/register//$1

What do I miss?

Answer 1

You cannot use mod_alias(redirectmatch) in that way. You have to use mod_rewrite if you want to match based on the hostname.

RewriteEngine On
RewriteCond %{HTTP_HOST} ^sub\.domain\.com$
RewriteRule ^register/(.*)$ http://domain.com/register/$1 [R=301,L]

If the .htaccess is in the root of sub.domain.com then you can just do this but using the absolute path.

RedirectMatch 301 ^/register/(.*)$ http://domain.com/register/$1