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 permis
       sions you specify are those which are to be allowed (not denied)
       to the users specified.
