mod_rewrite .htaccess causing 500 server error if URl does not exist

Question

I\'ve just started using mod_rewrite, this is what I use for a quite basic structured website with multiple language support:

RewriteEngine on
ErrorDocument          


        

Answer 1

Helmut, try this (the last rule is the reason for the 500 internal error, and this also includes the suggestion of @DaveRandom to merge rule 2 and 3):

RewriteEngine on
ErrorDocument 404 /error404.php

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([a-zA-Z]{2})/([^/]+)$ $2.php?lang=$1 [L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([a-zA-Z]{2})/?$ index.php?lang=$1 [L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([a-zA-Z0-9]+)$ $1.php [L]

Answer 2

Your rules are looping. At a glance, it looks like your last one:

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([^/]+)$ $1.php [L]

Say I have this URL, http://your.domain.com/blah, and the file blah.php doesn't exist. This is what's happening.

1. URI = blah, !-f is true, it's not a file
2. URI = blah, !-d is true, it's not a directory
3. URI = blah, internal rewrite to blah.php
4. blah != blah.php, rewrite rules loop
5. URI = blah.php !-f is true, it's not a file
6. URI = blah.php !-d is true, it's not a directory
7. URI = blah.php, internal rewrite to blah.php.php
8. blah.php != blah.php.php, rewrite rules loop

This goes on until the rewrite engine has had enough and returns a 500 server error.

You can do one of 2 things here:

1. Add a directive to make all looping stop no matter what, which is an easy to get around this kind of stuff. But it will break rules that require looping. I don't see anything like that in your rules so it's safe (at least for now) to do this. Just add this to the top of your rules:

   RewriteCond %{ENV:REDIRECT_STATUS} 200
   RewriteRule ^ - [L]
   

2. Do a pre-emptive check to see if the php file actually exists:

   RewriteCond %{REQUEST_FILENAME} !-f
   RewriteCond %{REQUEST_FILENAME} !-d
   RewriteCond %{REQUEST_FILENAME}.php -f
   RewriteRule ^([^/]+)$ $1.php [L]