Path_info vs. Request_uri Environment Variables

["Roger Haase" <haaserd@xxxxxxxxx>]

I have been unable to find any documentation that clearly states the difference between the path_info and request_uri environment variables.

The cgi specs at 

   http://cgi-spec.golux.com/draft-coar-cgi-v11-03-clean.html 

define the path_info variable but do not mention request_uri.  The brief references I found related to Apache describe path_info as "extra" path information and describe request_uri similar to the cgi definition of path_info.  In the few instances where I dumped the output, the two variables seem to be the same.

But I have found that if a uri is changed with a rewite command, the request_uri contains the original browser path and the path_info contains the changed path.  

I am trying to debug a situation that uses a rewrite command to retrieve a MoinMoin based page. MoinMoin is using the request_uri variable resulting in a missing page response.   It looks like the fix to this problem is to just use path_info instead of request_uri, but I an concerned about other side-effects.

Any advise on the location of more documentation or the difference in values of these two variables?

Roger Haase