Lists all the character set description files (charmaps) in the
   public directory defined by the logical name SYS$I18N_LOCALE.  A
   charmap defines symbolic names and values of characters in a coded
   character set.  Charmaps are used by the LOCALE COMPILE command
   when compiling a locale.  A charmap file has the file type .CMAP.

   Format:

        LOCALE SHOW CHARACTER_DEFINITIONS