RewriteCond %{SERVER_NAME} syntax

Question

I am trying to understand the following syntax (see usage context below):

RewriteCond %{SERVER_NAME} ^example\.com$

I have the above (with real domain name in place of example) in my .htaccess file. I would like to force it to be www.example.com.

The website has SSL and the following SSL Coding was added by the SSL Install process at GoDaddy. So I trying to work with both this coding, and changing to force to www with the SSL.

# BEGIN GD-SSL
<IfModule mod_rewrite.c>
Options +FollowSymLinks
RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteCond %{HTTP_USER_AGENT} ^(.+)$
RewriteCond %{SERVER_NAME} ^example\.com$
RewriteRule .* https://%{SERVER_NAME}%{REQUEST_URI} [R=301,L]
Header add Strict-Transport-Security "max-age=300"
</IfModule>
# END GD-SSL

I tried to add mod rewrite rules to force www and they are not working. I think the problem resides in the RewriteCond %{SERVER_NAME} ^example.com$ which is not resolving to the "www". I thought I might need to add the www. to this, however, I am not sure if this is correct.
Would this be the solution to change the ssl to force WWW in the URL? Or do I need to do something else entirely?

 RewriteCond %{SERVER_NAME} ^www\.^example\.com$

Any help would be greatly appreciated. Thank you.

Becky

Solution

To match against both www and non-www host in a single line, you can use the following regex pattern :

^(www\.)?example\.com$

This matches www.example.com or example.com .

To force ssl www, you can use this :

RewriteEngine on

RewriteCond %{HTTPS} !on
RewriteCond %{HTTP_HOST} ^(www\.)?example\.com$
RewriteRule (.*) https://www.example.com/$1 [L,R,NE]