The type of the option, as a #GOptionArg
If the @arg type is %G_OPTION_ARG_CALLBACK, then @arg_data must point to a #GOptionArgFunc callback function, which will be called to handle the extra argument. Otherwise, @arg_data is a pointer to a location to store the value, the required type of the location depends on the @arg type: - %G_OPTION_ARG_NONE: %gboolean - %G_OPTION_ARG_STRING: %gchar* - %G_OPTION_ARG_INT: %gint - %G_OPTION_ARG_FILENAME: %gchar* - %G_OPTION_ARG_STRING_ARRAY: %gchar** - %G_OPTION_ARG_FILENAME_ARRAY: %gchar** - %G_OPTION_ARG_DOUBLE: %gdouble If @arg type is %G_OPTION_ARG_STRING or %G_OPTION_ARG_FILENAME, the location will contain a newly allocated string if the option was given. That string needs to be freed by the callee using g_free(). Likewise if @arg type is %G_OPTION_ARG_STRING_ARRAY or %G_OPTION_ARG_FILENAME_ARRAY, the data should be freed using g_strfreev().
The placeholder to use for the extra argument parsed by the option in --help output. The @arg_description is translated using the @translate_func of the group, see g_option_group_set_translation_domain().
the description for the option in --help output. The @description is translated using the @translate_func of the group, see g_option_group_set_translation_domain().
Flags from #GOptionFlags
The long name of an option can be used to specify it in a commandline as --long_name. Every option must have a long name. To resolve conflicts if multiple option groups contain the same long name, it is also possible to specify the option as --groupname-long_name.
If an option has a short name, it can be specified -short_name in a commandline. @short_name must be a printable ASCII character different from '-', or zero if the option has no short name.
A GOptionEntry struct defines a single option. To have an effect, they must be added to a #GOptionGroup with g_option_context_add_main_entries() or g_option_group_add_entries().