apache2 设置目录的访问权限
apache2 下对/usr/local/share/lxr/目录设置认证访问控制，具体如下

Alias /lxr /usr/local/share/lxr/
<Directory /usr/local/share/lxr/>
AllowOverride All
Options All
AuthType Basic
AuthName "By Invitation Only"
AuthUserFile /etc/apache2/passwd/passwords  #创建密码文件
AuthGroupFile /etc/apache2/passwd/groups
Require user baiduyi  #可访问的用户
</Directory>

可参考apache2.2 中文手册 -apache 认证、授权、访问控制http://lamp.linux.gov.cn/Apache/ApacheMenu/howto/auth.html