01重定向：abc.com到www.abc.com
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} !^www.abc.com$ [NC]
RewriteRule ^(.*)$ http://www.abc.com/$1 [L,R=301]
或者
Options +FollowSymLinks
RewriteEngine on
RewriteCond %{HTTP_HOST} ^abc\.com
RewriteRule ^(.*)$ http://www.abc.com/$1 [R=permanent,L]
或者
Options +FollowSymLinks
RewriteEngine On
RewriteCond %{HTTP_HOST} ^abc\.com$ [NC]
RewriteRule ^(.*)$ http://www.abc.com/$1 [R=301,L]
301重定向：www.abc.com 到 abc.com
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} !^abc.com$ [NC]
RewriteRule ^(.*)$ http://abc.com/$1 [L,R=301]
301重定向：单个页面的301转向
Redirect 301 /a.html http://www.xyz.com/b.html
Apache配置中实现301转向
<VirtualHost xxx.xxx.xxx.xxx>
ServerName domain.com
DocumentRoot /home/domain/www
</VirtualHost>
<VirtualHost xxx.xxx.xxx.xxx>
ServerName www.domain.com
Redirect 301 / http://domain.com/
</VirtualHost>
[...]
