[htaccess] Redirect primary domain from http to https but exclude all subdomains

Hi all

I want to redirect my primary domain to https (http:// www. website.com to https:// www. website.com) and exclude all sub domains. (http:// xyz. website.com to remain as http:// xyz. website.com)

I have been on google for too long and couldnt find the right solution, please help

My .htaccess file

RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule (.*) https:// %{HTTP_HOST}%{REQUEST_URI} [R,L]

- Slax

 

RewriteCond %{HTTPS} off
RewriteCond %{HTTP_HOST} www.mydomain.com
RewriteRule (.*) https://www.mydomain.com/$1 [R=301,L]

Code (ApacheConf):

I think the rule could be just

RewriteRule (.*) https://www.mydomain.com$1 [R=301,L]

Code (markup):

leaving out the extra slash, which should be included in the rule match. But I always forget whether that works or not.

 

What is wrong with your current .htaccess? Seems like it should do the job
Additionally, you should exclude robots.txt file from this rule, to make it accessible for Search Engines like this

RewriteEngine On
RewriteCond %{HTTPS} off
RewriteCond %{REQUEST_URI} !/robots.txt
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}

PHP: