This is a really cool idea I had to make my Apache .htaccess mod_rewrite code much shorter and easier to manage multiple Redirections when using sites with both HTTP and HTTPS. Basically instead of having to check for HTTPS using a RewriteCond for every redirect that can be HTTP or HTTPS, I found out I can set an environment variable 1 time to determine if HTTP or HTTPS is being used for that request, and by giving the variable a value of "https" for HTTPS or "http" for HTTP I can remove all duplicate rewriterule blocks. This is sweet I'm telling you!
This is the old way I would have to use to redirect /index.html to / and urls with // to /.
RewriteEngine On
RewriteBase /
RewriteCond %{HTTPS} !=on
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(.*)index.html HTTP/ [NC]
RewriteRule ^.*$ http://%{SERVER_NAME}/%1 [R=301,L]
RewriteCond %{HTTPS} =on
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(.*)index.html HTTP/ [NC]
RewriteRule ^.*$ https://%{SERVER_NAME}/%1 [R=301,L]
RewriteCond %{HTTPS} !=on
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(.*)//(.*) HTTP/ [NC]
RewriteRule ^.*$ http://%{SERVER_NAME}/%1/%2 [R=301,L]
RewriteCond %{HTTPS} =on
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(.*)//(.*) HTTP/ [NC]
RewriteRule ^.*$ https://%{SERVER_NAME}/%1/%2 [R=301,L]
First I set the environment variable ps to have the value "http" for HTTP requests, or "https" for HTTPS requests. Once that is accomplished, I can use %{ENV:ps} in all of my rewriterules and it will result in https for SSL requests and http for non-ssl requests!
RewriteCond %{HTTPS} =on
RewriteRule ^(.*)$ - [env=ps:https]
RewriteCond %{HTTPS} !=on
RewriteRule ^(.*)$ - [env=ps:http]
# redirect urls with index.html to folder
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(.*)index.html HTTP/ [NC]
RewriteRule ^.*$ %{ENV:ps}://%{SERVER_NAME}/%1 [R=301,L]
# change // to /
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(.*)//(.*) HTTP/ [NC]
RewriteRule ^.*$ %{ENV:ps}://%{SERVER_NAME}/%1/%2 [R=301,L]
The top guru I have ever seen in my lengthy .htaccess related web travels is a moderator on the WebmasterWorld.com Apache Forum, jdMorgan. Upon seeing the above solution that I came up with, jdMorgan instantly provided an improvement, resulting in being able to set the environment variable in 1 rewrite block instead of 2. This is truly Sweet.
RewriteCond %{SERVER_PORT}s ^(443(s)|[0-9]+s)$
RewriteRule ^(.*)$ - [env=askapache:%2]
# redirect urls with index.html to folder
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /([^/]+/)*index.html HTTP/
RewriteRule ^(([^/]+/)*)index.html$ http%{ENV:askapache}://%{HTTP_HOST}/$1 [R=301,L]
# change // to /
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(.*)//(.*) HTTP/ [NC]
RewriteRule ^.*$ http%{ENV:askapache}://%{HTTP_HOST}/%1/%2 [R=301,L]