Apache mod_rewrite for SEO urls, but rewrite to 404 if file doesn't exist - apache

Question

I'm unable to find the answer for this, so please let me know if it's been resolved before.
I'm using mod_rewrite to do "pretty" URLs, but if you request a file that doesn't exist (like, a typo) it will redirect and add .php a bunch of times and then fail. The code I have below:
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !(.*)/$
RewriteRule ^(.*)$ http://inquisito.rs/$1/ [R=301,l]
RewriteRule ^(.*)/$ /$1.php [L]
So if you go to http://inquisito.rs/aion/ it will show you the aion page, but if you go to, lets say, inquisito.rs/aio/ on accident, it gives this
http://inquisito.rs/aio.php.php.php.php.php.php.php.php.php.php.php.php.php.php.php.php.php.php.php.php/
Thanks in advance, I can't tell you how many times I've used information from here to resolve issues at work and at home.

Answer 1

Using the example you've given, this is how the rules are applied:
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f # /aio/ is not a file, so this matched
RewriteCond %{REQUEST_URI} !(.*)/$ # This DOES NOT match, because you have a trailing slash
RewriteRule ^(.*)$ http://inquisito.rs/$1/ [R=301,L] # This rule doesn't run, because the condition above wasn't met
# This rule is separate from the RewriteConds above
RewriteRule ^(.*)/$ /$1.php [L] # This does match because of the lack of RewriteConds and because you have a trailing slash
Try this (untested) set of rules instead:
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f # Make sure no matching file exists
RewriteCond %{REQUEST_URI} !\.php$ # Don't match requests that already end .php
RewriteCond %{REQUEST_URI} !(.*)/$ # Check for missing trailing slash
RewriteRule ^(.*)$ http://inquisito.rs/$1/ [R=301,L] # Redirect with trailing slash
# Separate rule
RewriteCond %{REQUEST_URI} !\.php$ # Don't match requests that already end .php
RewriteRule ^(.*)/$ /$1.php [L] # Internal redirect to matching PHP file
It's important to note that all matching RewriteRules cause a new request to be processed by htaccess again.