Command to check if CD-R is empty

[Steven P. Ulrick]

Hello, Everyone :)
I am really naughty about labeling cd's and keeping unlabeled ones
separate from blank ones.  I used to be able to check CD-R's using
XCdroast to see if they were empty or not.  But since my only burner is
an external USB2 drive, XCdroast doesn't even pick it up anymore, so I
can't check CD-R's anymore to see if they are blank.  I guess I have two
questions, both of which I have not been able to find any answers to as
of yet:
1. Is there a command I can use to determine whether a CD-R is empty or
not?  XCdroast determined that information somehow, so I figure that if
I could find out the command that it used, I could use it myself :)
2. Anybody have any idea how to get my USB2 drive recognized by
XCdroast, so that I can do it that way?  I don't usually use graphical
programs to make cd's, but when I do, I only use XCdroast, so it would
be nice to get it to recognize my USB2 drive.

Any help you can give me is greatly appreciated :)
Steven P. Ulrick