How to obtain folder from Uri

[TonyB]

I am trying to build a fairly simple spider, that takes in a Url,
downloads the page, extracts all links, and then downloads those.

The only problem I am struggling to crack is how to restrict the
downloaded links to only those from within the starting folder.

I am trapping the ResponseUri from the first Request in order to cope
with Redirection. From this I can determine the Host, but not the
folder.

e.g. if the Url = www17.brinkster.com/johnsmith/default.htm
I want www17.brinkster.com/johnsmith/
but the Host = www17.brinkster.com
the LocalPath = /johnsmith/default.htm

I would use the Uri.Segments, as this gives
1) /
2) johnsmith/
3) default.htm

so in this case I could remove the last item from the list, and build
my path from the rest.

But I have tried sites where the following segments would be listed
1) /
2) johnsmith

In which case I want all of them!

Is what I am trying to do possible?

Thanks,
Tony

[TonyB]

I have tried Path.GetDirectoryName(CustomerUrl.LocalPath)
which is useful for sites where the Uri contains the file to load as
well - e.g Home.html, Default.aspx

but for example: "http://news.bbc.co.uk/sport" returns "/sport" as the
LocalPath which is then gives a DirectoryName of "/" and a FileName of
"sport".

So the key bit I think is that both
/folder and /folder/file.aspx can point to the same thing, with some
sites using one construction and some the other.
How do I differentiate between the two?

Cheers,

Tony