and get the "Hello, world!" but even when I add "DirectoryIndex index.php" to the top of the fatfree-master/.htaccess, I can not get
Here is the fatfree-master .htaccess. :
DirectoryIndex index.php
# Enable rewrite engine and route requests to framework
RewriteEngine On
# Some servers require you to specify the `RewriteBase` directive
# In such cases, it should be the path (relative to the document root)
# containing this .htaccess file
#
RewriteBase /fatfree-master/
RewriteRule ^(tmp)\/|\.ini$ - [R=404]
RewriteCond %{REQUEST_FILENAME} !-l
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule .* index.php [L,QSA]
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L]
Thanks for replying so quickly!!