Force SSL/https using .htaccess and mod_rewrite

From : http://www.besthostratings.com/articles/force-ssl-htaccess.html

Sometimes you may need to make sure that the user is browsing your site over securte connection. An easy to way to always redirect the user to secure connection (https://) can be accomplished with a .htaccess file containing the following lines:

RewriteEngine On
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://www.example.com/$1 [R,L]

Please, note that the .htaccess should be located in the web site main folder.

In case you wish to force HTTPS for a particular folder you can use:

RewriteEngine On
RewriteCond %{SERVER_PORT} 80
RewriteCond %{REQUEST_URI} somefolder
RewriteRule ^(.*)$ https://www.domain.com/somefolder/$1 [R,L]

The .htaccess file should be placed in the folder where you need to force HTTPS.