Dynamic domain htaccess redirection

Question

I created www domain redirection in htaccess file:

RewriteEngine On 
RewriteCond %{HTTP_HOST} ^example\.com
RewriteRule ^(.*)$ http://www.example.com/$1 [R=permanent,L]
ErrorDocument 404 /

All works, but I do not want enter manualy domain name every time. How to change example.com to dynamic domain name? Can somebody help me?

Answer 1

You can use:

ErrorDocument 404 /
RewriteEngine On 

RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L,NE]