.htaccess RewriteRule $1 contains wrong value

Question

I have a RewriteRule that is not behaving as I expect. I want site.com/author/fred to map to site.com/author/index.php?a=fred

I have an author directory within the site root. The author directory contains the .htaccess file below.

My problem is that $1 contains the value index.php instead of the regex match.

The entire .htaccess file is below. Can you see my mistake? Thank you.

Options +FollowSymlinks
RewriteEngine on

RewriteRule ([^/]+)/?$  index.php?a=$1 [NC,L]

Answer 1

Your pattern ([^/]+)/?$ will match fred as well as index.php.

The key here -- the way how [L] flag works. After initial rewrite of fred occurs it goes to next rewrite iteration, where it will rewrite index.php?a=fred to index.php?a=index.php. Because URL was rewritten, it goes to 3rd iteration, where index.php?a=index.php will be rewritten to the same URL index.php?a=index.php. Because input and output URLs are the same, rewrite exits and you have what you have right now.

You need to add a condition to prevent looping. For example (one of the possible approaches):

RewriteCond %{REQUEST_URI} !index\.php$
RewriteRule ([^/]+)/?$  index.php?a=$1 [NC,L]

or

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ([^/]+)/?$  index.php?a=$1 [NC,L]

or even

RewriteRule (?!index\.php)([^/]+)/?$  index.php?a=$1 [NC,L]

Read a bit more: RewriteRule Last [L] flag not working?