如何用.htaccess重写将主域名指向一个子目录/文件夹:

在虚拟主机中，主域名是使用public_html目录/文件夹作为主域名的缺省目录，主域名网站的文件和程序都是放在public_html目录下，附加的域名(addon domains)使用public_html目录/文件夹下的子目录/子文件夹。有的人可能觉得public_html目录/文件夹下的会看起来比较乱，因此想把主域名也指向其中一个子目录/文件夹。这样就需要利用.htaccess的重写功能。

具体的写法如下：

# .htaccess main domain to subfolder redirect
# Copy and paste the following code into the .htaccess file
# in the public_html folder of your hosting account
# make the changes to the file according to the instructions.

# Do not change this line.

RewriteEngine on

# Change yourdomain.com to be your main domain.

RewriteCond %{HTTP_HOST} ^(www.)?yourmaindomain.com$

# Change ’subfolder’ to be the folder you will use for your main domain.

RewriteCond %{REQUEST_URI} !^/subfolder/

# Don’t change this line.

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d

# Change ’subfolder’ to be the folder you will use for your main domain.

RewriteRule ^(.*)$ /subfolder/$1

# Change yourdomain.com to be your main domain again.
# Change ’subfolder’ to be the folder you will use for your main domain
# followed by / then the main file for your site, index.php, index.html, etc.

RewriteCond %{HTTP_HOST} ^(www.)?yourmaindomain.com$
RewriteRule ^(/)?$ subfolder/index.php [L]

据说会有性能问题，观后效吧