I think you misunderstood my question. I didn't want a tcp wrapper. i could do that easily by putting it in inetd.conf.
I want a text-wrapper that takes whatever you are inputting in the keyboard (before you hit enter or something at shell) and scans it against a bunch of specific, crucial words. Like, a root password or soemthing so that you can only type in the root password into a pid that is a child of an SU or something.
Do you understand now?