mod_rewrite question

You can do this

RewriteRule ^(.*) index.php?file=$1
ErrorDocument 404 notfound.php

but

how do you redirect a missing file, i.e. 404 with the file name to another location?

For example

on 404 redirect to site.com/file?file=$1

Any ideas?

Some say it can be done, others say it can't.

 

Check the environment vars REDIRECT_URL and REDIRECT_QUERY_STRING