The basic syntax is similar to the %build, %install, and other sections of the rpm spec file.
The scripts support a special flag, -p which allows the scriptlet to invoke a single program
directly rather than having to spawn a shell to invoke the programs.(ie: %post -p /sbin/ldconfig)
さりとて rpm のソース見ると高級そう。短時間ではとても無理かな。
Lua はとりあえず rpm-4.4.2/lua/README を見ましょう
* What is Lua?
Lua is a powerful, light-weight programming language designed for extending
applications. Lua is also frequently used as a general-purpose, stand-alone
language. Lua is free software.