Chapter 1, What is Bash?, opens the book by giving a clear definition of what the Bash shell actually is, where it fits in with other programs on a Unix system, and how to find and (if necessary) install it on your system.
Chapter 2, Bash Command Structure, looks at the anatomy of Bash command lines, starting with simple single commands and arguments, and moves on through running multiple commands, and good quoting practices for data.
Chapter 3, Essential Commands, examines a list of common commands useful in Bash command lines and scripts, explaining the situations in which each is useful and how to use them; listing, searching, sorting, and slicing data are all discussed.
Chapter 4, Input, Output, and Redirection
