Contents Foreword ...................................................................................................................xi About the Authors ................................................................................................. xiii About the Technical Editor .....................................................................................xv Acknowledgments................................................................................................. xvii Chapter 0: Introduction ..........................................................................................xix CHAPTER 1 On Shell Scripting .........................................................................1 What is a shell? ........................................................................2 What is a script? .......................................................................3 Shell scripts...............................................................................3 Where shell scripting is useful .................................................4 UNIX, Linux, and OS X shell scripting .......................................5 Shell availability and choices...................................................5 Working with shells ..................................................................7 Bash basics ....................................................................................8 Hello World ..............................................................................8 Variables..................................................................................10 Arguments...............................................................................10 Control statements ..................................................................11 Introduction to command shell scripting ................. 1