rem: const char *authors, void (*usage_func)())
add: void (*usage_func) (int),  ...)
context: parse_long_options (int argc,		    char **argv,		    const char *command_name,		    const char *package,		    const char *version,		    const char *authors,		    void (*usage_func)()){  int c;  int saved_opterr;  saved_opterr = opterr;  /* Don't print an error message for unrecognized options.  */  opterr = 0;  if (argc == 2      && (c = getopt_long (argc, argv, "+", long_options, NULL)) != -1)    {      switch (c)	{	case 'h':	  (*usage_func) (0);	case 'v':	  version_etc (stdout, command_name, package, version, authors);	  exit (0);	default:	  /* Don't process any other long-named options.  */	  break;	}    }  /* Restore previous value.  */  opterr = saved_opterr;  /* Reset this to zero so that getopt internals get initialized from     the probably-new parameters when/if getopt is called later.  */  optind = 0;}