HTTP -> HTTPS로 할 경우

<ifModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{HTTPS} off
    RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
</ifModule>

---

모바일 사이트와 데스크톱 사이트의 전환

<ifModule mod_rewrite.c>
    RewriteEngine On
    RewriteBase /
    RewriteCond %{REQUEST_URI} !/mobile/
    RewriteCond %{HTTP_USER_AGENT} (iPod|iPhone|Android.*Mobile|Windows.\ Phone)
    RewriteRule ^(.*)$ mobile/$1 [R]
    RewriteCond %{REQUEST_URI} /mobile/
    RewriteCond %{HTTP_USER_AGENT} !(iPod|iPhone|Android.*Mobile|Windows.\ Phone)
    RewriteRule ^mobile/(.*)$ $1 [R]
</ifModule>

---

www.helloworld.com에 접속해도
helloworld.com으로 접속하도록 유도

<ifModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{HTTP_HOST} ^www\.helloworld\.com$
    RewriteRule ^(.*)$ https://helloworld.com/$1 [R=301,L]
</ifModule>

helloworld.com에 접속해도
www.helloworld.com으로 접속하도록 유도

<ifModule mod_rewrite.c>
    RewriteEngine on
    RewriteCond %{HTTP_HOST} ^helloworld\.com$
    RewriteRule ^(.*)$ https://www.helloworld.com/$1 [R=301,L]
</ifModule>

---

하부 URL경로가 바뀌었을 경우
helloworld.com/hello -> helloworld.com/world

<ifModule mod_rewrite.c>
    RewriteEngine On
    RewriteRule ^hello(.*)$ /world$1 [R=301,L]
</ifModule>

URL을 완전히 바꾸었을 때
https://helloworld.com/newbie/newbie.html 로 접속했을 때
https://new-helloworld.com/begineer/start.html 로 리다이렉트 시켜줌

<ifModule mod_rewrite.c>
    RewriteEngine On
    RewriteRule https://helloworld.com/newbie/newbie.html https://new-helloworld.com/begineer/start.html [R=301,L]
</ifModule>

많이들 쓰는 방법은 요정도?
정리가 필요하면 하나씩 더 추가..