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)

What Bash is and is not

On reading the preceding definition, you may have noticed a few things you might have expected are missing. There is a lot of confusion out there about what Bash is and is not. Here are some common misconceptions:

  • Bash is not (necessarily) part of Linux. They are separate pieces of software. GNU Bash existed for several years before the Linux kernel was created, and runs on other operating systems too.
  • Bash is not the same thing as SSH. SSH is a service and network protocol for running commands on remote computers. bash can be one such command.
  • Bash is also not your terminal or TTY. Your terminal is a device for sending information to, and receiving information from, a computer. Terminals used to be hardware devices with a monitor and keyboard. Nowadays, for most users, they are terminal emulators, or software devices. Bash is a program that runs using your terminal for its input and output.
  • Similarly, Bash is not the same thing as PuTTY, iTerm, or xterm. These are terminal emulators, not shells. Your terminal emulator is a program that understands and interprets text-based programs. Bash is one such program.
  • Bash is not the command line, in the strictest sense. Bash has an interactive mode, which is an example of a command line, but many other tools have command lines, and not just system shells. The bc calculator tool is an example of another tool with a command line.

Now that you know this, if someone ever asks you for a PuTTY account on your server, make sure to set them straight!