htaccess rewrite is giving me 500 error?

Question

i have this url that i wanted to make friendly, using rewrite on .htacess but it gives me an error(500 internal server error), this is my orginal php url

http://www.example.com/viewtopic.php?topic=lovetopic

i want to change it to this:

http://www.example.com/lovetopic

this is my whole htaccess code is this:

RewriteEngine On
RewriteRule ^user/([^/]*)$ /viewprofile.php?user=$1 [L]
RewriteRule ^([^/]*)$ /viewtopic.php?topic=$1 [L]

i dont know what the problem is

EDIT the server error log is giving me this error

[Thu Oct 14 20:34:36 2010] [error] Request exceeded the limit of 10 internal redirects due to probable configuration error. Use 'LimitInternalRecursion' to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace., 

Answer 1

The pattern of your second rule ^([^/]*)$ does also match /viewtopic.php without the path prefix /, i.e. viewtopic.php. That’s why you’re having an infinite recursion.

You can use the following condition to exclude that:

RewriteCond $1 !=viewtopic.php
RewriteRule ^([^/]*)$ /viewtopic.php?topic=$1 [L]

Or use this condition to exclude all existing files:

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^/]*)$ /viewtopic.php?topic=$1 [L]

Or use this rule in front of you other rules to stop every request that can be mapped to an existing file being rewritten by any following rules:

RewriteCond %{REQUEST_FILENAME} -f
RewriteRule ^ - [L]