S9 LIB  (basename string)          ==>  string
        (basename string string2)  ==>  string

Return the rightmost component of the Unix path name given in
STRING. When STRING2 is given also remove a STRING2 suffix
(if any) from STRING.

(basename "/foo/bar/baz")     ==>  "baz"
(basename "/goo/bar.Z" ".Z")  ==>  "bar"
