Hour 13. Introduction to Command Shells

Welcome to your 13th hour of learning UNIX. You should take a moment to pat yourself on the back. You've come a long way, and you're already quite a sophisticated user. In the past few hours, I've occasionally touched on the differences between the shells, but I haven't really stopped to explain what shells are available, how they differ from one another, and which is the best for your style of interaction. That's what this hour is all about.

Shells, you'll recall, are the command-line interface programs through which you tell the computer what to do. All UNIX systems include C shell (csh) and its predecessor, the Bourne shell (sh). Some also include a newer version of the Bourne shell, called the Korn shell (ksh), and a new rewrite of sh humorously called the Bourne Again shell (bash).