.htaccess: What's the difference between REQUEST_FILENAME and REQUEST_URI ?

[iMarks]

I've been trying to use the REQUEST_FILENAME rules that Miva puts into .htaccess. When I need more parameters, I try to make more rules following those REQUEST_FILENAME examples, and often my urls don't work. Now I am going back to using REQUEST_URI for everything.

Is it better to use REQUEST_FILENAME rather than REQUEST_URI ? If so, why? Can anyone point me to a tutorial on it? Is it bad to mix the 2 kinds of rules?

[Brandon MUS]

Re: .htaccess: What's the difference between REQUEST_FILENAME and REQUEST_URI ?

Filename should give you the complete local path, where request uri will be exactly what was requested (should also include the GET parameters). From the manual:

REQUEST_URI
The resource requested in the HTTP request line. (In the example above, this would be "/index.html".)
REQUEST_FILENAME
The full local filesystem path to the file or script matching the request.