htaccess 301使用WordPress和子域进行重定向

Question

Basically I am trying to redirect a few of my subdomains, and all of the pages in that sub directory, to the root directory now that I have my site updated. So it would go something like this:

usa.example.com --> example.com
can.example.com --> example.com
th.example.com --> example.com

This is what I was suggested to use but no luck:

        ## EXPIRES CACHING ##
        <IfModule mod_expires.c>
        ExpiresActive On
        ExpiresByType image/jpg "access 1 year"
        ExpiresByType image/jpeg "access 1 year"
        ExpiresByType image/gif "access 1 year"
        ExpiresByType image/png "access 1 year"
        ExpiresByType text/css "access 1 month"
        ExpiresByType application/pdf "access 1 month"
        ExpiresByType text/x-javascript "access 1 month"
        ExpiresByType application/x-shockwave-flash "access 1 month"
        ExpiresByType image/x-icon "access 1 year"
        ExpiresDefault "access 2 days"
        </IfModule>
        ## EXPIRES CACHING ##


        # BEGIN WordPress and SEO Rewrites

        <IfModule mod_rewrite.c>
        RewriteEngine On
        RewriteBase /

        RewriteCond %{HTTP_HOST}^australia|canada|china)\.example\.com$ [NC]     
        RewriteRule ^(.*)$ http://example.com/ [R=301,L]

        RewriteRule ^index\.php$ - [L]
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteCond %{REQUEST_FILENAME} !-d
        RewriteRule . /index.php [L]
        </IfModule>

        # END WordPress and SEO Rewrites

Answer 1

RewriteCond %{HTTP_HOST} ^(australia|canada|china)\.example\.com$ [NC]     
RewriteRule ^(.*)$ http://example.com$1 [R=301,L]

OR, if the subdomains are the first ones you mentioned, then

RewriteCond %{HTTP_HOST} ^(usa|can|th)\.example\.com$ [NC]     
RewriteRule ^(.*)$ http://example.com$1 [R=301,L]