       set [ +-options ] [ +-o option name ] ... [ -A [name] ] [
              arg  ] ...
              Set the options for the shell and/or set the  posi-
              tional  parameters,  or  declare an array.  For the
              meaning of the flags, see OPTIONS above.  Flags may
              be  specified  by name using the -o option.  If the
              -A flag is specified, name is set to an array  con-
              taining  the  given  args; if no name is specified,
              all arrays are printed.  Otherwise  the  positional
              parameters  are  set.   If  no arguments are given,
              then the names and values  of  all  parameters  are
              printed  on the standard output.  If the only argu-
              ment is +, the names of all parameters are printed.

       unset [ -m ] name ...
              Each named parameter is unset. If the  -m  flag  is
              specified  the  arguments  are  taken  as  patterns
              (should be quoted) and all parameters with matching
              names are unset.
