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.
