remove iptables rule

C++
#find line number of rule
$ sudo iptables -L INPUT --line-numbers
## delete rule by number
$ sudo iptables -D INPUT 1
. . .# flag -D for delete
sudo iptables -D INPUT -i eth0 -p tcp --dport 22 -j ACCEPTsudo iptables -F
Source

Also in C++: