Bash cookbook : leverage bash scripting to automate daily tasks and improve productivity / Ron Brash, Ganesh Naik.

Format:

Book

Author/Creator:

Brash, Ron, author.

Contributor:

Naik, Ganesh, editor.

Language:

English

Subjects (All):

Linux.

User interfaces (Computer systems).

Physical Description:

1 online resource (260 pages) : illustrations

Edition:

1st edition

Place of Publication:

Birmingham ; Mumbai : Packt, 2018.

System Details:

text file

Summary:

Create simple to advanced shell scripts and enhance your system functionality with effective recipes Key Features Automate tedious and repetitive tasks Create several novel applications ranging from a simple IRC logger to a Web Scraper Manage your system efficiently by becoming a seasoned Bash user Book Description In Linux, one of the most commonly used and most powerful tools is the Bash shell. With its collection of engaging recipes, Bash Cookbook takes you through a series of exercises designed to teach you how to effectively use the Bash shell in order to create and execute your own scripts. The book starts by introducing you to the basics of using the Bash shell, also teaching you the fundamentals of generating any input from a command. With the help of a number of exercises, you will get to grips with the automation of daily tasks for sysadmins and power users. Once you have a hands-on understanding of the subject, you will move on to exploring more advanced projects that can solve real-world problems comprehensively on a Linux system. In addition to this, you will discover projects such as creating an application with a menu, beginning scripts on startup, parsing and displaying human-readable information, and executing remote commands with authentication using self-generated Secure Shell (SSH) keys. By the end of this book, you will have gained significant experience of solving real-world problems, from automating routine tasks to managing your systems and creating your own scripts. What you will learn Understand the basics of Bash shell scripting on a Linux system Gain working knowledge of how redirections and pipes interact Retrieve and parse input or output of any command Automate tasks such as data collection and creating and applying a patch Create a script that acts like a program with different features Customize your Bash shell and discover neat tricks to extend your programs Compile and install shell and log commands on your system's console using Syslog Who this book is for The Bash Cookbook is for you if you are a power user or system administrator involved in writing Bash scripts in order to automate tasks. This book is also ideal if you are interested in learning how to automate complex daily tasks.

Contents:

Cover

Title Page

Copyright and Credits

Packt Upsell

Contributors

Table of Contents

Preface

Chapter 1: Crash Course in Bash

Getting started with Bash and CLI fundamentals

Your first Bash script with Vim

Creating and using basic variables

Hands-on variable assignment

Hidden Bash variables and reserved words

Conditional logic using if, else, and elseif

Evaluating binary numbers

Evaluating strings

Nested if statements

Case/switch statements and loop constructs

Basic case statement

Basic loops

For loop

Do while loop

Until loop

Using functions and parameters

Using a function with parameters within a for loop

Including source files

Including/importing a library script and using external functions

Retrieving return codes and output

Return code 101

Linking commands, pipes, and input/output

Redirection and pipe bonzanza

Getting program input parameters

Passing your program flags

Getting additional information about commands

Summary

Chapter 2: Acting Like a Typewriter and File Explorer

Introduction

Basic searching for strings and files

Getting ready

How to do it...

How it works...

Using wildcards and regexes

Math and calculations in script

Striping/altering/sorting/deleting/searching strings with Bash only

Using SED and AWK to remove/replace substrings

Formatting your data/output using echo and printf

Readying your script for different languages with internationalization

How it works.

Calculating statistics and reducing duplicates based on file contents

Using file attributes with conditional logic

Reading delimited data and altered output format

Chapter 3: Understanding and Gaining File System Mastery

Viewing files from various angles - head, tail, less, and more

Searching for files by name and/or extension

Creating a diff of two files and patching

Creating symbolic links and using them effectively

Crawling filesystem directories and printing a tree

Finding and deleting duplicate files or directories

Joining and splitting files at arbitrary positions

Generating datasets and random files of various size

Chapter 4: Making a Script Behave Like a Daemon

Running a program continuously (forever) using looping constructs or recursion

Keeping programs/scripts running after logoff

Invoking commands when they require permissions

Sanitizing user input and for repeatable results

Making a simple multi-level user menu using select

How to do it.

How it works...

Generating and trapping signals for cleanup

Using temporary files and lock files in your program

Leveraging timeout when waiting for command completion

Creating a file-in-file-out program and running processes in parallel

Executing your script on startup

Chapter 5: Scripts for System Administration Tasks

Gathering and aggregating system information

Gathering network information and connectivity diagnostics

Configuring basic network connectivity

Monitoring directories and files

Compressing and archiving files

Rotating files from RAM to storage for log rotation

Adding configuration to /etc/logrotate.d/

Using Linux iptables for a firewall

Accessing SQL databases remotely or locally

Creating SSH keys for password less remote access

Creating and configuring cron Jobs for task scheduling

Creating users and groups systematically

Chapter 6: Scripts for Power Users

Creating Syslog entries and generating an alarm

Getting ready.

How to do it...

Backing up and erasing media, disks, and partitions with DD

Creating graphics and presentations on the CLI

Checking for file integrity and tampering

Mounting network file systems and retrieving files

Browsing the web from the CLI

Capturing network traffic headlessly

Finding binary dependencies

Fetching time from different locations

Encrypting/decrypting files from a script

Chapter 7: Writing Bash to Win and Profit

Creating a lame utility HTTP server

How to do it…

How it works…

Parsing RSS feeds and output HTML

Scraping the web and collecting files

Making a simple IRC chat bot logger

Blocking IP addresses from failed SSH attempts

Playing and managing audio from Bash

Creating a simple NAT and DMZ firewall

Parsing a GitHub project and generate a report

Creating a poor man's incremental remote backup

How it works….

Using Bash scripts to monitor udev input

Using Bash to monitor battery life and optimize it

Using chroot and restricted Bash shells to secure scripts

Chapter 8: Advanced Scripting Techniques

Calculating and reducing the runtime of a script

Writing one-line conditional statements and loops

Avoiding command not found warnings/errors and improving portability

Creating a config file and using it in tandem with your scripts

Improving your shell - GCC and command line colors

Adding aliases, and altering user paths/variables

Echoing output to raw terminal devices

Creating simple frontend GUIs for Bash scripts

Compiling and installing your own Bash shell

Recording terminal sessions for automation

Writing high-quality scripts by example

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Index.

Notes:

Includes index.

Description based on print version record.

ISBN:

9781788839174

178883917X

OCLC:

1048789321