[wp-hackers] WP's Physical Path

[Keith Murray]

Hi,

I apologize if this is a question with a well-documented answer, but 
I've been looking for a while and haven't come up with one.  I have a 
plugin that needs to reference a physical path on the host.  Is there a 
WP variable that stores the physical path?  Or is there a method of 
retrieving the physical path of your WP root in some other fashion?

What I need to get is a path like:
/home/users/my_account/somedomain.com/wordpress

Ideally this could be done with little or no knowledge of this 
information by the blogger using the WP plugin.

Thanks,

Keith.