Basis mod_rewrite rule results in 500 internal server error - .htaccess

Question

I have this very basic rewrite rule, no matter what I try, results in an Error 500.
RewriteEngine On
RewriteRule ^folder/(.*) /folder/index.php?Alias=$1 [L]
My httpd.conf file has the following content: (which seems OK to me)
<Directory "/var/www/html">
Options -Indexes FollowSymLinks
AllowOverride All
Order allow,deny
Allow from all
<IfModule mod_suphp.c>
suPHP_Engine On
suPHP_UserGroup webapps webapps
SetEnv PHP_INI_SCAN_DIR
</IfModule>
</Directory>
Any suggestions on what might be going wrong? I've also tried to add $ at the end of my rewrite rule.

Answer 1

The rewrite engine will loop repeatedly, until the URI stops changing, or the internal redirect limit is reached which causes the 500 error to be thrown. Your rule's target URI /folder/index.php will get thrown back into the rewrite engine and your same rule's regex matches it, ^folder/(.*). So you'll need to add some kind of condition to prevent the loop.
RewriteEngine On
RewriteCond %{REQUEST_URI} !^/folder/index\.php
RewriteRule ^folder/(.*) /folder/index.php?Alias=$1 [L]
This is simple, it simply won't apply the rule if it already starts with /folder/index\.php. You can also try:
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^folder/(.*) /folder/index.php?Alias=$1 [L]
This is a little less restrictive of a condition. It only applies the rule if the requested URI doesn't map to an existing file or directory. This assumes that when you try to go to /folder/blahblah there isn't a directory or file blahblah and that you want to route it through your index.php.