How to map authenticated Nginx users to their own directory?

I am writing a social networking site in C and serving it all up with Nginx. How can I make it so that authenticated users go to their own directory -ONLY- where a user-specific index.html resides. I am not asking how to populate the index.html with user specific directives, but how to lock them into their own directory

Solution 1:

map $remote_user $profile_directory {
    default      $remote_user;
    ''           guests;
    pavel        admins;
    ivan         admins;
}

server {

    location /profile/ {
        alias /path/to/www/$profile_directory/;
        ...
    }

}

• http://nginx.org/en/docs/http/ngx_http_core_module.html#variables
• http://nginx.org/r/map
• http://nginx.org/r/alias
• http://nginx.org/r/root
• http://nginx.org/r/location

second example (see comments):

server {
    location / {
        auth_basic            "Please Login";
        auth_basic_user_file  "/etc/nginx/htpasswd";
        root /var/www/sites/mysite.com/http/$remote_user;
    }
}