1 CDIRECTORY
  Syntax: CDIRECTORY dirname
  where   dirname  is the directory name

  Sets the current HBOOK or ROOT directory name to `dirname'. Note that the
  HCDIR command is executed immediately, whereas it is only executed when you
  do `FETCH', `LDIR', `ZDIR' or `SHOW DIR' after a `SET DIR' command.  You
  should therefore always use `SET DIR' before a `FETCH' command.

  Note that the  directory name  should not be  preceded by a '/'. However
  '//' is allowed so you can go to the top level. You can use either
!^
  '\' or '..' to go up a directory level.
!$\backslash$ or '..' to go up a directory level.

  ROOT directory names are always with respect to the top level
  directory. Therefore it make no sense to try to use '..' to go up a
  level. Use the command 'cd //root' to get to the top level. ROOT directories
  are case sensitive. HBOOK directories always get converted to upper case.

  Note that the Mn_Fit HBOOK file top level directory name is `//MN_HBIN',
  while the ROOT top level directory name is '//root'.

