The shell is a vast topic that is often, deservedly, the sole subject of a book. Since we want to cover other topics in this book, we must be somewhat restrictive about what we include here. This chapter is geared toward the novice system administrator, but we have tried to include more advanced concepts so that people at most levels will find at least something of interest. After a quick discussion on the different shells available, we will concentrate on the Korn Shell and cover such topics as shell and environment variables, simple shell scripting, positional parameters, wildcards and other shell metacharacters, redirection, piping, and command line parsing. We also include some example shell scripts at the end of the chapter.