Apache .htaccess : How to use .htaccess on Apache

Options -Indexes 

IndexIgnore *

<Files ~ "^\.ht">
deny from all
</Files>

OK : http://www.example.com/
NG : http://user.rental-server.com/example.com/

SetEnvIf Host "^www\.example\.com$" hos_ok
order deny,allow
deny from all
allow from env=hos_ok 

RewriteEngine On RewriteRule ^(.*)$ http://new.com/

http://old.com/ -> http://new.com/
http://old.com/test1.html -> http://new.com/
http://old.com/test2.html -> http://new.com/

Redirect permanent / http://new.com/

http://old.com/ -> http://new.com/
http://old.com/test1.html -> http://new.com/test1.html
http://old.com/test2.html -> http://new.com/test2.html

RewriteEngine On
RewriteRule  old.html$ http://new.com/dir/new.html [R=301,L]

http://old.com/old.html -> http://new.com/new.html