Mod_Rewrite existing file check goes pear shaped, or passes wrong querystring.

Question

I'm using Apache, Python (fastcgi), mod_rewrite.

I want

http://foo/bar

to redirect internally to

http://main.py?q=foo/bar

Now my .htacess file contains

Options +ExecCGI
AddHandler cgi-script .py
DirectoryIndex main.py

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f 
RewriteCond %{REQUEST_FILENAME} !-d 
RewriteRule (.*) main.py?q=$1

Normally works fine. Redirects to main.py with the query-string q=foo/bar But if I have a script named foo.py it instead directs to foo.py instead of main.py.

I tried removing the RewriteConds and have the RewriteRule alone as a catch-all.

Then it always redirects to main.py ok, but the query-string passed to my script is q=main.py where it should be q=foo/bar

Now there's various kludges I could try involving restructuring my code, file layout etc, but I'd like figure out what's going on before it causes more problems down the track.

So I want to either a) stop it thinking that foo means foo.py or b) make it skip the existing file checks completely and pass on the correct query-string.

Answer 1

It sounds like a problem with content negotiation. Try adding...

Options -Multiviews

...at the top of your .htaccess file.

Answer 2

Your first problem is caused by MultiViews, which is resolving the non-existent resource foo/bar to the existing file foo.py, then likely passing it PATH_INFO of /bar. You can disable it in your .htaccess file by modifying your Options:

Options -MultiViews +ExecCGI

Using your original ruleset with MultiViews disabled should solve your problem. For the sake of completeness though, the reason why the query string ends up being q=main.py is because of the how the request is processed when you remove the rewrite conditions:

• mod_rewrite receives the request, and foo/bar matches .* and is rewritten to main.py?q=foo/bar
• mod_rewrite performs an internal redirect and assigns itself as the handler
• The redirect is re-processed by mod_rewrite, and main.py matches .* and is rewritten to main.py?q=main.py
• mod_rewrite performs an internal redirect and assigns itself as the handler
• The redirect is re-processed by mod_rewrite, and main.py matches .* and is rewritten to main.py?q=main.py
• mod_rewrite realizes that you're going to enter an infinite loop redirecting the same request to itself, and stops the redirection process