Pam配置文件有条件地执行语句

I am working on a project to make a pam module in linux to authenticate via typing behavior of an individual. I have adequately studied and have an idea about the working of the four control flags in the pam config file viz. requisite, required, sufficient and optional. I have the following 2 questions about the PAM config file specific to my project.I am working on a project to make a pam module