I have drupal installed in a subfolder drupal, but I want to access pages as it is in root folder: http://www.example.com instead of http://www.example.com/drupal

I'm able to have this working, but it's also working with url containing subfolder, so I have http://www.example.com and a clone site in http://www.example.com/drupal

What is the rule to forbid access to subfolder?

I want all url starting with http://www.example.com/drupal being forbidden.

This is .htaccess in / directory:

Options -Indexes

Options +FollowSymLinks

<IfModule mod_rewrite.c>
  RewriteEngine on
  RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
  RewriteRule ^ http://%1%{REQUEST_URI} [L,R=301]
  RewriteRule ^(.*+)$ drupal/$1 [L,QSA]
</IfModule>

And this is drupal .htaccess in /drupal/ directory:

Options -Indexes
Options +FollowSymLinks
ErrorDocument 404 index.php
DirectoryIndex index.php index.html index.htm

# Override PHP settings that cannot be changed at runtime. See
# sites/default/default.settings.php and drupal_initialize_variables() in
# includes/bootstrap.inc for settings that can be changed at runtime.

# PHP 5, Apache 1 and 2.
<IfModule mod_php5.c>
  php_flag magic_quotes_gpc                 off
  php_flag magic_quotes_sybase              off
  php_flag register_globals                 off
  php_flag session.auto_start               off
  php_value mbstring.http_input             pass
  php_value mbstring.http_output            pass
  php_flag mbstring.encoding_translation    off
</IfModule>

# Requires mod_expires to be enabled.
<IfModule mod_expires.c>
  # Enable expirations.
  ExpiresActive On

  # Cache all files for 2 weeks after access (A).
  ExpiresDefault A1209600

  <FilesMatch \.php$>
    # Do not allow PHP scripts to be cached unless they explicitly send cache
    # headers themselves. Otherwise all scripts would have to overwrite the
    # headers set by mod_expires if they want another caching behavior. This may
    # fail if an error occurs early in the bootstrap process, and it may cause
    # problems if a non-Drupal PHP file is installed in a subdirectory.
    ExpiresActive Off
  </FilesMatch>
</IfModule>

# Various rewrite rules.
<IfModule mod_rewrite.c>
  RewriteEngine on

  # Block access to "hidden" directories whose names begin with a period. This
  # includes directories used by version control systems such as Subversion or
  # Git to store control files. Files whose names begin with a period, as well
  # as the control files used by CVS, are protected by the FilesMatch directive
  # above.
  RewriteRule "(^|/)\." - [F]

  # To redirect all users to access the site WITH the 'www.' prefix,
  # (http://example.com/... will be redirected to http://www.example.com/...)
  # uncomment the following:
  # RewriteCond %{HTTP_HOST} !^www\. [NC]
  # RewriteRule ^ http://www.%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
  #
  # To redirect all users to access the site WITHOUT the 'www.' prefix,
  # (http://www.example.com/... will be redirected to http://example.com/...)
  # uncomment the following:
  RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
  RewriteRule ^ http://%1%{REQUEST_URI} [L,R=301]

  RewriteBase /drupal

  # Pass all requests not referring directly to files in the filesystem to
  # index.php. Clean URLs are handled in drupal_environment_initialize().
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_URI} !=/favicon.ico
  #RewriteRule ^ index.php [L]
  RewriteRule ^(.*)$ index.php?q=$1 [L,QSA]

  # Rules to correctly serve gzip compressed CSS and JS files.
  # Requires both mod_rewrite and mod_headers to be enabled.
  <IfModule mod_headers.c>
    # Serve gzip compressed CSS files if they exist and the client accepts gzip.
    RewriteCond %{HTTP:Accept-encoding} gzip
    RewriteCond %{REQUEST_FILENAME}\.gz -s
    RewriteRule ^(.*)\.css $1\.css\.gz [QSA]

    # Serve gzip compressed JS files if they exist and the client accepts gzip.
    RewriteCond %{HTTP:Accept-encoding} gzip
    RewriteCond %{REQUEST_FILENAME}\.gz -s
    RewriteRule ^(.*)\.js $1\.js\.gz [QSA]

    # Serve correct content types, and prevent mod_deflate double gzip.
    RewriteRule \.css\.gz$ - [T=text/css,E=no-gzip:1]
    RewriteRule \.js\.gz$ - [T=text/javascript,E=no-gzip:1]

    <FilesMatch "(\.js\.gz|\.css\.gz)$">
      # Serve correct encoding type.
      Header append Content-Encoding gzip
      # Force proxies to cache gzipped & non-gzipped css/js files separately.
      Header append Vary Accept-Encoding
    </FilesMatch>
  </IfModule>
</IfModule>