Bash in easy steps

Mike McGrath

• Publisher: In Easy Steps Limited
• Year: 2019
• ISBN:
  9781840788563
• Topic: Ciencia de la computación
• Subtopic: Sistemas operativos

The Bourne Again SHell (Bash) is a powerful command-line shell interface that lets you communicate directly with the kernel at the heart of a computer's operating system for total control. Bash is the default shell for Unix-based operating systems Linux, Mac OS X, and Raspbian on Raspberry Pi devices, and is also available to Windows users on the Windows Subsystem for Linux (WSL).

This book will show you how to use the Bash command-line interface and how to employ Bash's programming abilities. Complete examples illustrate each aspect with colorized source code and full-color screenshots depict the actual output.

Bash in easy steps begins by demonstrating Bash commands for system navigation and file manipulation so you will quickly become familiar with the command-line interface. It explains all the BASH basics before moving on to describe advanced features such as command history, command-line editing, and environment customization. The book then introduces Bash programming with examples of flow control, command switches, input/output, and debugging - allowing you to create your own executable programs by copying the examples.

Bash in easy steps has an easy-to-follow style that will appeal to:

• Users who are completely new to Unix-based operating systems
• Casual users who wish to expand their knowledge of their computer system
• Those who would like to learn coding skills by writing useful shell scripts
• The student who is studying programming at school or college
• Those seeking a career in computing and need a fundamental understanding of the BASH interpreter on Unix-based operating systems
• Table of Contents:
• Getting Started
• Managing Files

1

Getting Started

This chapter introduces the Bash command interpreter shell and demonstrates essential basic commands.

Introducing Bash

Discovering the Shell

Installing Linux on Windows

Initializing the Distro

Understanding Commands

Navigating the File System

Dealing Wildcards

Recognizing Metacharacters

Quoting Phrases

Getting Help

Summary

Introducing Bash

Computer operating systems include a command-line interpreter that allows the user to communicate directly with the system by typing text commands at a waiting prompt. The command-line interpreter is a “shell” facility that will process the input command and produce an appropriate output response.

GNU Bash logo

An early shell facility was created for the Unix operating system by Stephen Bourne at Bell Labs way back in 1979. This early “Bourne shell” (sh) proved to be very popular as it was both a command-line interpreter and a scripting language that supported most features needed to produce structured programs.

Ten years later, in 1989, a free software replacement for the Bourne shell was created by Brian Fox for the GNU Project. Recognizing its ancestry, the replacement shell was named “Bash” – an acronym for the phrase Bourne-again shell. The Bash command syntax is a superset of that in the Bourne shell, but incorporates many extensions that are lacking in the Bourne shell. Bash can efficiently process commands typed at a prompt and execute shell program scripts that have been saved as text files.

The GNU Project is a free-software mass collaboration project. You can discover more at gnu.org/gnu/thegnuproject.en.html

Today Bash is the default shell for most Linux operating systems, for Apple’s macOS operating system (formerly OS X), and for the Solaris Unix operating system.

The Bash command-line processor typically runs in a text window. This is similar to the Command Prompt window found in the Windows operating system in which users can type commands to be interpreted by the Windows Command Processor.

Microsoft has recognized the power and popularity of Bash by introducing support for “WSL” (Windows Subsystem for Linux) in the Windows 10 operating system. This allows users to run a Linux environment directly on Windows so they can issue Bash commands at a shell prompt, create and execute Bash shell scripts, and run Linux command-line applications.

This book describes and demonstrates how to utilize the power of Bash with examples that can be run natively in a “Terminal” text window on a Linux operating system a...