unsetopt [ {+|-}options | {+|-}o option name ] [ name ...
       ]
       Unset the options for the shell.  All options spec-
       ified either with flags or by name are  unset.   If
       no arguments are supplied, the names of all options
       currently unset are printed.  If  the  -m  flag  is
       given  the  arguments  are taken as patterns (which
       should be quoted to preserve them from being inter-
       preted  as  glob  patterns),  and  all options with
       names matching these patterns are unset.
