Path: /x/y.c
   dir = '/x'
   name = 'y.c'
   ext = 'c'

Path: a.b
   dir = '.'
   name = 'a.b'
   ext = 'b'

Path: a.b.c
   dir = '.'
   name = 'a.b.c'
   ext = 'c'

Path: /e/x
   dir = '/e'
   name = 'x'
   ext = ''

Path: /e.o/x
   dir = '/e.o'
   name = 'x'
   ext = ''

Path: /u/r/.e
   dir = '/u/r'
   name = '.e'
   ext = ''

Path: rms/.e.o
   dir = 'rms'
   name = '.e.o'
   ext = 'o'