+static int hash_callback(const struct option *opt, const char *arg, int unset)
+{
+ hash_only = 1;
+ /* Use full length SHA1 if no argument */
+ if (!arg)
+ return 0;
+ return parse_opt_abbrev_cb(opt, arg, unset);
+}
+
+static int exclude_existing_callback(const struct option *opt, const char *arg,
+ int unset)
+{
+ exclude_arg = 1;
+ *(const char **)opt->value = arg;
+ return 0;
+}
+
+static int help_callback(const struct option *opt, const char *arg, int unset)
+{
+ return -1;
+}
+
+static const struct option show_ref_options[] = {
+ OPT_BOOLEAN(0, "tags", &tags_only, "only show tags (can be combined with heads)"),
+ OPT_BOOLEAN(0, "heads", &heads_only, "only show heads (can be combined with tags)"),
+ OPT_BOOLEAN(0, "verify", &verify, "stricter reference checking, "
+ "requires exact ref path"),
+ OPT_BOOLEAN('h', "head", &show_head, "show the HEAD reference"),
+ OPT_BOOLEAN('d', "dereference", &deref_tags,
+ "dereference tags into object IDs"),
+ { OPTION_CALLBACK, 's', "hash", &abbrev, "n",
+ "only show SHA1 hash using <n> digits",
+ PARSE_OPT_OPTARG, &hash_callback },
+ OPT__ABBREV(&abbrev),
+ OPT__QUIET(&quiet),
+ { OPTION_CALLBACK, 0, "exclude-existing", &exclude_existing_arg,
+ "pattern", "show refs from stdin that aren't in local repository",
+ PARSE_OPT_OPTARG | PARSE_OPT_NONEG, exclude_existing_callback },
+ { OPTION_CALLBACK, 0, "help-all", NULL, NULL, "show usage",
+ PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
+ OPT_END()
+};
+