# Fragments of shell tutorial on the cutting room floor:
You already know enough to enable you to get around very well in the shell environment. You have also learned to program in shell, since all you have to do is type the commands you've already learned into a file, add execute permissions to the file, and it's ready to invoke.

But wait a minute!
I promised you that Unix shells are powerful,
but you haven't heard anything powerful yet!
Shells have several features which make them very powerful: