This book opens with a tour of the history and function of traditional Unix shells (from Bourne, C, and Korn shells) before centering on Linux variants, bash and tcsh. The text then turns to three powerful utilities: grep (for file searching), sed (for noninteractive file editing), and gawk (which allows programmers to write powerful scripts that process files using regular expressions).

There are dozens of sample commands to try out here. (With shell programming, the genius is truly in the details, and the only way to learn the shell is to try it out for yourself.) As an experienced teacher, the author provides a wealth of examples that take you through both the common and more esoteric features of these utilities. Instead of hard-to-decipher man pages, there she includes dozens of sample commands with correct syntax, plus clear explanations.

The rest of this book looks at the bash and tcsh shells in detail, from interactive mode to shell programming with full coverage of the basics of writing reusable scripts. Final sections of Linux Shells by Example look at common Linux file and system commands for easy reference, and the book ends with a useful appendix on quoting styles for five different shells. In all, this book's clear presentation style and plentiful examples will help any Linux user become a competent shell user and script programmer. --Richard Dragan

Topics covered: Survey of Unix shells (the Bourne, C, and Korn shells), survey of Linux shells (the Bourne Again and TC shells), processes, shell environments, tutorial for regular expressions, grep for file searches, the streamlined editor (sed), awk/nawk/gawk scripts, gawk basics and expressions, gawk programming (variables, arrays, flow control, built-in and user-defined functions), the bash and tcsh shells (interactive mode, programming tutorial for shell scripts), reference to common Linux/Unix utilities, comparison of shells, and tips for using correct quoting styles within shells.