/* This call is similar to hwconfig_arg(), except that it takes an additional argument @subopt, and so works with sub-options.  */
const char* hwconfig_subarg(const char *opt, const char *subopt, size_t *subarglen)
/* This call is similar to hwconfig_arg(), except that it takes an additional argument @subopt, and so works with sub-options.  */
const char* hwconfig_subarg(const char *opt, const char *subopt, size_t *subarglen)
{
	size_t arglen;
	const char *arg;
	arg = __hwconfig(opt, &arglen);
	if (!arg)
		return NULL;
	return hwconfig_parse(arg, arglen, subopt, ',', '=', subarglen);
}