How to write htaccess for subdomain redirection to https

问题

How to write htaccess rules for redirect example.com to www.example.com and also we have number of subdomains for example subdomain.example.cpm so i need to redirect it to https://subdomain.example.com. but when i write htaccess rules it is going to loop. please send how to write conditions for this.

回答1:

Put this code in your DOCUMENT_ROOT/.htaccess file:

RewriteEngine On

# example.com to www.example.com
RewriteCond %{HTTP_HOST} ^example\.com$ [NC]
RewriteRule ^ http://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L,NE]

# http to https for subdomains
RewriteCond %{HTTPS} off
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L,NE]

来源：https://stackoverflow.com/questions/20840669/how-to-write-htaccess-for-subdomain-redirection-to-https