remove part of url via mod_rewrite - .htaccess

Question

Is there any way to hide part of a Url via mod_rewrite. I am currently using part of the url, .htm, to split the page that is being requested and the query string.
Example
http://www.example.com/page/article/single.htm/articleid=8
This would let me know that the page requested is:
http://www.example.com/page/article/single
And the quest string is:
article=8
Ideally i would like the have this to work the same url without the .htm visible
http://www.example.com/page/article/single/articleid=8
The number of variables in the query sting varies as does the number of levels before the .htm so the rule would need to be dynamic
Thanks

Answer 1

To also do multiple querystring parameters, how do you want it to look? I started with this, which keeps this simple, then got trickier below.
http://www.example.com/page/article/single/articleid=8&anothervar=abc
Try this rule:
RewriteRule ^([^=]+)/(.+)$ $1.htm?$2 [NC,L]
This handles one or more querystring parameters, but does require at least one. This looks for anything without an = up to a slash, then everything else. Basically, it uses the = as the indicator of the path vs. the querystring portions; but actually splits it on the slash. (The NC is a habit of mine; not needed in this case, but when I leave it out I forget it when it's needed.)
To let querystrings be optional, so it could handle just
http://www.example.com/page/article/single
I found it easiest with two rules, instead of trying to mingle this into one rule:
RewriteRule ^([^=]+)$ $1.htm [NC,L]
RewriteRule ^([^=]+)/(.+)$ $1.htm?$2 [NC,L]
You can do something even prettier, using slashes for everything including multiple querystring parameters, like this:
http://www.example.com/page/article/single/articleid=8/anothervar=abc
It's a little hairy, but I think this works (couldn't let it go...)
Another rule handles replacing the slashes with ampersands, then doing the rewrite as above. This was easier to keep straight - maybe there's a way to do it all at once, but this was tricky enough for me:
RewriteRule ^([^=]+)$ $1.htm [NC,L]
RewriteRule ^([^=]+)/([^=]+=[^/]+)/([^=]+=.+)$ $1/$2&$3 [NC,LP]
RewriteRule ^/([^=]+)/(.+)$ /$1.htm?$2 [NC,L]
The first rule is as above, handling no querystrings at all. That just gets it out of the way.
The second rule is a loop LP, which is what I tend to find in examples whenever you have an unknown number of replacements. In this case, it's replacing the last querystring-slash with an ampersand, and looping until there's only one left (leaving that for the question mark in the third rule).
It's looking for the last one of these articleid=8/anothervar=abc where there are two parameters left. It replaces the slash with an ampersand like articleid=8&anothervar=abc
In words, it's looking for (and capturing in parentheses):
(not-equalsign) slash (not-equalsign equalsign not-slash) slash (not-equalsign equalsign anything)
This lines up as:
(not-equalsign) /page/article/single
slash /
(not-equalsign equalsign not-slash) articleid = 8
slash /
(not-equalsign equalsign anything) anothervar = abc
It replaces the last slash with an ampersand, and after looping, turns it into the first draft above: http://www.example.com/page/article/single/articleid=8&anothervar=abc . The third rule handles this as described above.
A note: These also assume all your urls will look like this, since they're going to tack on .htm to everything. If you want still allow explicit /something/page.htm then these rules would need to not-match on .htm if it's already there - something like that. Or maybe an initial rule up front that looks for .htm and just stops rewriting there. Or maybe only do this for the /page paths.