Function usage

lib_acl/samples/dns_req/main.cpp:106–110

}

static void usage(const char *procname)
{
	printf("usage: %s -s dns_ip_list[192.168.0.1:192.168.0.2]"
		" -p dns_port -d domain_list[www.sina.com.cn:www.sohu.com]\r\n", procname);
}

int main(int argc, char *argv[])
{