umask [ -S ] [ mask ]
       The  umask is set to mask.  mask can be either an octal number or a
       symbolic value as described in the chmod(1) man page.  If  mask  is
       omitted,  the  current  value is printed.  The -S option causes the
       mask to be printed as a symbolic value.   Otherwise,  the  mask  is
       printed  as  an  octal  number.  Note that in the symbolic form the
       permissions you specify are those which are to be allowed (not  de-
       nied) to the users specified.
