improvement of a mod_rewrite rule - regex

Question

Could you have a look at the code below and say if this is the correct way to do it please.
In order to redirect from:
http://blog.exampledomain.com/2013/10/testpage.html
to
https: //exampledomain.com/blog/testpage/
I have placed the below rewrite rules in 2 .htaccess files:
In the .htaccess file in root of exampledomain.com I have placed:
RewriteCond %{HTTP_HOST} ^blog\.exampledomain\.com$ [NC,OR]
RewriteCond %{HTTP_HOST} ^www\.blog\.exampledomain\.com$ [NC]
RewriteRule ^(.*)$ https://exampledomain.com/blog/$1 [R=301,L]
In the .htaccess file in the blog folder in exampledomain.com/blog I have placed:
RewriteRule ^([0-9]{4})/([0-9]{2})/(.*)\.html https://exampledomain.com/blog/$3/ [R=301,L]
Questions:
Is this the correct way to do it?
Does this mean in this setup we have 2 redirects? (which is probably not good for SEO) Should these be combined? How?

Answer 1

These two redirects should be combined into one.
In the .htaccess file in the document root of your subdomain (which looks it might be the same as the document root of the main domain? Or in the main domains .htaccess file - if this is a parent directory on the filesystem), try the following:
RewriteEngine On
RewriteCond %{HTTP_HOST} ^(www\.)?blog\.exampledomain\.com$
RewriteRule ^\d{4}/\d\d/(.+)\.html$ https://exampledomain.com/blog/$1/ [R,L]
When you are sure this is working OK then change the temporary redirect (R) into a permanent one (R=301).
UPDATE: To also redirect from: http://blog.exampledomain.com/ to https://exampledomain.com/blog/ and http://blog.exampledomain.com/whatever to https://exampledomain.com/blog/whatever, add the following directives after the above:
RewriteCond %{HTTP_HOST} ^(www\.)?blog\.exampledomain\.com$
RewriteRule ^(.*)$ https://exampledomain.com/blog/$1 [R,L]