Book Image

Bash Quick Start Guide

By : Tom Ryder
Book Image

Bash Quick Start Guide

By: Tom Ryder

Overview of this book

Bash and shell script programming is central to using Linux, but it has many peculiar properties that are hard to understand and unfamiliar to many programmers, with a lot of misleading and even risky information online. Bash Quick Start Guide tackles these problems head on, and shows you the best practices of shell script programming. This book teaches effective shell script programming with Bash, and is ideal for people who may have used its command line but never really learned it in depth. This book will show you how even simple programming constructs in the shell can speed up and automate any kind of daily command-line work. For people who need to use the command line regularly in their daily work, this book provides practical advice for using the command-line shell beyond merely typing or copy-pasting commands into the shell. Readers will learn techniques suitable for automating processes and controlling processes, on both servers and workstations, whether for single command lines or long and complex scripts. The book even includes information on configuring your own shell environment to suit your workflow, and provides a running start for interpreting Bash scripts written by others.
Table of Contents (10 chapters)

Best Practices

In this final chapter, we'll look at some techniques for programming in Bash defensively, safely, and productively, in a way that makes working with shell scripts a joy rather than a chore, especially by avoiding some nasty pitfalls in the language.

We'll revisit the following material from earlier chapters in more depth:

  • Quoting correctly
  • Handling filenames starting with dashes
  • Separating output and diagnostics

We'll also cover:

  • Keeping scripts brief and simple
  • Keeping scripts flexible
  • Respecting and applying the user's configuration
  • Allowing scripts to run without user input
  • Limiting the scope of shell state changes
  • Avoiding path anti-patterns
  • Avoiding Bash for untrusted user input
  • Documenting scripts
  • Using temporary files cleanly
  • Cleaning up after a script
  • A tool to check shell scripts for problems