What is the difference in operation between . and ^ and ^(.*)$?

Question

What is the difference in operation between:

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^ index.php [L]

and

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php [L]

and

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php [L]

I know that "." means any character and "^" beginning of string.

Thanks for reply!

Answer 1

First let's understand how landing page is matched.

For landing page URI pattern is ^$ in .htaccess, ^/$ in Apache config. Thus you can safely use ^/?$ universally.

1. Your first rewrite rule will match every URL (including landing page i.e. http://domain.com/).
2. Your second rewrite rule will match every URL (except landing page). As single DOT will not match ^$ URI pattern.
3. Your third rewrite rule will also match every URL (including landing page i.e. http://domain.com) but has an unnecessary capturing group and longish version of just ^.