Hypertext Access file Rewriting and Redirecting www and non-www redirects
Example
Redirect any naked domain to www.[your_domain].tld:
# Start Apache Rewriting engine
RewriteEngine On
# Make sure you're not already using www subdomain
# and that the host string is not empty
RewriteCond %{HTTP_HOST} !^$
RewriteCond %{HTTP_HOST} !^www\.
# We check for http/https connection protocol
RewriteCond %{HTTPS}s ^on(s)|
# In case the previous conditions matches, redirect to www
RewriteRule ^(.*)$ http%1://www.%{HTTP_HOST}/$1 [R=301,L]
Redirect www.[your_domain].tld to [your_domain].tld
# Start Apache Rewriting engine
RewriteEngine On
# We check if we're on the www subdomain
RewriteCond %{HTTP_HOST} ^www\.([^\.]+\.[^\.]+)$
# In case the previous condition matches, redirect to non-www
RewriteRule ^(.*)$ http://%1/$1 [R=301,L]
Redirect any level of nested subdomains to your main domain:
# Start Apache Rewriting engine
RewriteEngine On
# We check if there's a subdomain
RewriteCond %{HTTP_HOST} \.([^.]+\.[^.]+)$
# redirect to the main domain name
RewriteRule ^ http://%1%{REQUEST_URI} [R=301,L]
