Sitemap.xml file and https - how to write?

Question

HTML

If the site is transferred to https, should the site.ru/post links be changed to https://site.ru/post ?

Answer 1

Yes, and everything.
Alternating protocols can lead to incorrect indexing of the site by search engines.
And if the site supports encryption, then redirect everyone who goes to http:

RewriteEngine On
 RewriteCond %{HTTPS} !=on
 RewriteRule ^.*$ https://%{SERVER_NAME}%{REQUEST_URI} [R,L]

Answer 2

I did find . -type f -name "*.*" -exec sudo sed -i 's! http://!//!g ' {} \;
That is, I replaced http:// with simply //
Now the browser chooses the protocol itself. So does Google, so does Yandex, etc.
Browsers have supported this feature since the 90s, so no problem.