const char *family = NULL;
    Tcl_DString ds;
    int result;

    if (host != NULL) {
	if (Tcl_UtfToExternalDStringEx(interp, NULL, host, -1, 0, &ds,
		NULL) != TCL_OK) {
		Tcl_DStringFree(&ds);
	    return 0;
	}
	native = Tcl_DStringValue(&ds);
    }

    /*
     * Workaround for OSX's apparent inability to resolve "localhost", "0"

    if (result != 0) {
	*errorMsgPtr =
#ifdef EAI_SYSTEM	/* Doesn't exist on Windows */
		(result == EAI_SYSTEM) ? Tcl_PosixError(interp) :
#endif /* EAI_SYSTEM */
		gai_strerror(result);
        return 0;
    }

    /*
     * Put IPv4 addresses before IPv6 addresses to maximize backwards
     * compatibility of [fconfigure -sockname] output.
     *
     * There might be more elegant/efficient ways to do this.