Ok what i meant is the user when executing the script gets a user input and some custom commands as like help or anything which i code myself, but i wanna to make a tool that allows the user to do a lot on his system as in scanning for perl backdoors etc for security so there would be modules, what i want is the user to do use <module> and perl to understand that if the users puts use then a module that perl needs to read what is after use and see if the module exist if it does it executes it, is it more clear? If not type on google "Metasploit hacking tuto" its the only tool i can think of that shows what i'm asking for. Is it more clear?