Tom Ryder - Bash Quick Start Guide Get Up and Running with Shell Scripting with Bash

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Tom Ryder is a systems administrator living in New Zealand who works for an internet services provider. He loves terminals, text editors, network monitoring and security, Unix and GNU/Linux, shell script, and programming in general. He is also the author of the Nagios Core Administration Cookbook .

Fabio Alessandro Locati commonly known as Fale is the director at Otelia, a public speaker, author, and open source contributor. His primary areas of expertise are Linux, automation, security, and cloud technologies. Fale has more than 14 years' experience working in IT, with many of them spent consulting for companies, including dozens of Fortune 500 companies. Fale has written Learning Ansible 2, OpenStack Cloud Security, and has been part of the review process for multiple books.

Janos Gyerik is a passionate software developer. He enjoys building software whatever the programming language, both at work and in his spare time. He helps fellow programmers by answering questions on Stack Overflow, or by giving feedback on their code on Code Review Stack Exchange. Janos makes Android apps such as Programming and Bash Quiz, and websites such as Bash One-Liners, and is always up to some geeky projects.

Cory Sadowski is an IT professional living in the United States, specializing in Perl and shell programming, GNU/Linux, and, despite best efforts, Windows administration. He loves most things GNU/Linux, video games, and other such sophisticated topics.

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The GNU Bourne-Again Shell, or Bash, is the best-known Bourne-style shell in the world, and is installed or available for installation on a huge variety of Unix-like systems. Even professionals who don't do a lot of work with Unix or Linux will need to use the Bash shell occasionally.

Bash is a language of contradictions; while it's the best-known and most widely-deployed shell of its kind, it's perhaps also one of the least-understood tools, with a terse syntax that's relatively unique among modern programming languages and can seem bizarre even to experienced users. Bash is powerful in some ways, and very limited in others. It's clear, elegant, and expressive in some ways, and terse, clumsy, and bewildering in others.

Because it's so powerful and yet so complex, and because so many computer professionals can't avoid using it at least occasionally, Bash is often learned by way of a kind of "tradition;" demonstrations by experienced administrators, reading others' scripts, copying and pasting, and asking questions and reading answers on the internet. This leads to a lot of "cargo-cult programming," and a lot of bad practices that make things unnecessarily confusing at best, and downright dangerous at worst. The available documentation for Bash is often unhelpful in addressing this problemit often teaches the same bad practices, and even when it's correct, as the official Bash manual page is, it's often too complicated and assumes too much knowledge for new users to understand it.

To avoid all that, we'll start learning good Bash from first principles, and focus almost exclusively on writing the language