Iptables-preproc is a project mainly written in C and SHELL, it's free.
An experimental implementation to make iptables config suck less using the c preprocessor
Just a simple example/experiment of how to ease the (sometimes painful) configuration of iptables by using a C preprocessor and a number of well-chosen macros.
Credit for the initial implementation and idea goes to Anatole Shaw.
run the example like:
$ ./iptparser.sh ruleset.sh