unsetopt [ {+|-}options | {+|-}o option_name ] [ name ... ]
       Unset the options for the shell.  All options specified 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 interpreted as glob patterns),
       and all options with names matching these patterns are unset.
