<IfModule mod_rewrite.c>
RewriteEngine On RewriteBase /subdirectory RewriteRule ^index\.html$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-l RewriteRule . /index.html [L]
</IfModule>