One of the most useful functions of the .htaccess file is to redirect requests to different files, either on the same server, or on a completely different web site. It can be extremely useful if you change the name of one of your files but allow users to still find it. Another use (which I find very useful) is to redirect to a longer URL, for example in my newsletters I can use a very short URL for my affiliate links. The following can be done to redirect a specific file:
.htaccess最有用的功能之一就是将请求重定向到同站内或站外的不同文档。这在你改变了一个文件名称,但仍然想让用户用旧地址访问到它时,变的极为有用。另一个应用(我发现的很有用的)是重定向到一个长URL,例如在我的时事通讯中,我可以使用一个很简短的URL来指向我的会员链接。以下是一个重定向文件的例子:
Redirect /location/from/root/file.ext
http://www.othersite.com/new/file/location.xyz
In this above example, a file in the root directory called oldfile.html would be entered as:
上述例子中,访问在root目录下的名为oldfile.html可以键入:
/oldfile.html
and a file in the old subdirectory would be entered as:
访问一个旧次级目录中的文件可以键入:
/old/oldfile.html
You can also redirect whole directoires of your site using the .htaccess file, for example if you had a directory called olddirectory on your site and you had set up the same files on a new site at:
http://www.newsite.com/newdirectory/ you could redirect all the files in that directory without having to specify each one:
你也可以使用.htaccess重定向整个网站的目录。假如你的网站上有一个名为olddirectory的目录,并且你已经在一个新网站
http://www.newsite.com/newdirectory/上建立了与上相同的文档,你可以将旧目录下所有的文件做一次重定向而不必一一声明:
Redirect /olddirectory
http://www.newsite.com/newdirectory
Then, any request to your site below /olddirectory will bee redirected to the new site, with the
extra information in the URL added on, for example if someone typed in:
这样,任何指向到站点中/olddirectory目录的请求都将被重新指向新的站点,包括附加的额外URL信息。例如有人键入:

They would be redirected to:
请求将被重定向到:

This can prove to be extremely powerful if used correctly.
如果正确使用,此功能将极其强大。
Part 3 – 密码保护
Introduction 介绍
Although there are many uses of the .htaccess file, by far the most popular, and probably most useful, is being able to relaibly password protect directories on websites. Although JavaScript etc. can also be used to do this, only .htaccess has total security (as someone must know the password to get into the directory, there are no 'back doors')
尽管有各种各样的.htaccess用法,但至今最流行的也可能是最有用的做法是将其用于网站目录可靠的密码保护。尽管JavaScrip等也能做到,但只有.htaccess具有完美的安全性(即访问者必须知晓密码才可以访问目录,并且绝无“后门”可走)。
The .htaccess File 密码保护的.htaccess文件
Adding password protection to a directory using .htaccess takes two stages. The first part is to add the appropriate lines to your .htaccess file in the directory you would like to protect. Everything below this directory will be password protected:
利用.htaccess将一个目录加上密码保护分两个步骤。第一步是在你的.htaccess文档里加上适当的几行代码,再将.htaccess文档放进你要保护的目录下:
AuthName "Section Name"
AuthType Basic
AuthUserFile /full/path/to/.htpasswd
Require valid-user
There are a few parts of this which you will need to change for your site. You should replace "Section Name" with the name of the part of the site you are protecting e.g. "Members Area".
你可能需要根据你的网站情况修改一下上述内容中的一些部分,如用被保护部分的名字"Members Area",替换掉“Section Name”。
The /full/parth/to/.htpasswd should be changed to reflect the full server path to the .htpasswd file (more on this later). If you do not know what the full path to your webspace is, contact your system administrator for details.
/full/parth/to/.htpasswd则应该替换为指向.htpasswd文件(后面详述该文档)的完整服务器路径。如果你不知道你网站空间的完整路径,请询问一下你的系统管理员。