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)

Essential Bash builtin commands

The first category of essential commands that we'll examine are builtins: they are included as part of the bash program. In fact, the very first command we'll look at, called type, is itself designed to help you tell what any kind of command is.

For all of these commands, Bash can provide help on usage with the help program. For example, to get help on the type command, you would type:

bash$ help type

The type command

The type command, given the name of any command or commands, gives you information about what kind of command it is:

bash$ type echo
echo is a shell builtin
bash$ type grep
grep is /bin/grep

It identifies shell keyword, too:

bash$ type for
for is a shell keyword

We can...