       umask [ -S ] [ mask ]
              The umask is set to mask.  mask can  be  either  an
              octal  number  or  a symbolic value as described in
              chmod(1).  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 denied) to the users
              specified.
