OPT_BOOL_F('z', "null", &opt.null_following_name,
                           N_("print NUL after filenames"),
                           PARSE_OPT_NOCOMPLETE),
+               OPT_BOOL('o', "only-matching", &opt.only_matching,
+                       N_("show only matching parts of a line")),
                OPT_BOOL('c', "count", &opt.count,
                        N_("show the number of matches instead of matching lines")),
                OPT__COLOR(&opt.color, N_("highlight matches")),
        if (!opt.pattern_list)
                die(_("no pattern given."));
 
+       /* --only-matching has no effect with --invert. */
+       if (opt.invert)
+               opt.only_matching = 0;
+
        /*
         * We have to find "--" in a separate pass, because its presence
         * influences how we will parse arguments that come before it.