.htaccess for Codeigniter to avoid index.php and force www. before any URL

.htaccess

<IfModule mod_rewrite.c>
  RewriteEngine On
	RewriteCond %{HTTP_HOST} !^$
	
	# BEGIN force www before URL
	RewriteCond %{HTTP_HOST} !^www\. [NC]
	RewriteCond %{HTTPS}s ^on(s)|
	RewriteRule ^ http%1://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
	# END for www on URL
	
	RewriteCond %{REQUEST_FILENAME} !-f
	RewriteCond %{REQUEST_FILENAME} !-d
	RewriteRule ^(.*)$ ./index.php/$1 [L]
</IfModule>


<IfModule !mod_rewrite.c>
  ErrorDocument 404 index.php
</IfModule>

Not sure it's late to comment, but if you get me the code for .htaccess in how can I force to https and non-www site, that would be a big help here. FYI: the application running with Codeigniter 3.1.9 with Ubuntu 16.4 x64. Thanks in advance!