Applied Iptables Rules x Firewall Script

Hello, I want to compare the iptables firewalls rules that are in the memory and the firewall rules that are in the firewall script. It have to match. Someone can apply firewalls rules without put them in the script, just using cli, so, memory. Next time machine reboots, the firewall rules created "by hand" will be lost. The firewall script has a different format of iptables-save. I have some ideas, but i want to hear yours. I can´t reload the rule(flush and apply again), i just want the diff, if exists. Thank you.