Mastering Linux shell scripting master the complexities of Bash shell scripting and unlock the power of shell for your enterprise

✍ Scribed by Mallett, Andrew

• Publisher: Packt Publishing
• Year: 2015
• Tongue: English
• Series: Community experience distilled
• Category: Library

✦ Synopsis

Annotation;Cover ; Copyright; Credits; About the Author; About the Reviewer; www.PacktPub.com; Table of Contents; Preface; Chapter 1: What and Why of Scripting with Bash ; Bash vulnerabilities; The bash command hierarchy; Command type; Command PATH; Preparing text editors for scripting; Configuring vim; Configuring nano; Configuring gedit; Creating and executing scripts; Hello World!; Executing the script; Checking the exit status; Ensuring a unique name; Hello Dolly!; Running the script with arguments; The importance of correct quotes; Printing the script name; Debugging your scripts; Summary.

✦ Table of Contents

Cover
Copyright
Credits
About the Author
About the Reviewer
www.PacktPub.com
Table of Contents
Preface
Chapter 1: What and Why of Scripting with Bash
Bash vulnerabilities
The bash command hierarchy
Command type
Command PATH
Preparing text editors for scripting
Configuring vim
Configuring nano
Configuring gedit
Creating and executing scripts
Hello World!
Executing the script
Checking the exit status
Ensuring a unique name
Hello Dolly!
Running the script with arguments
The importance of correct quotes
Printing the script name
Debugging your scripts
Summary. Chapter 2: Creating Interactive Scripts Using echo with options
Basic script using read
Script comments
Enhancing scripts with read prompts
Limiting the number of entered characters
Controlling the visibility of entered text
Enhancing learning with simple scripts
Backing-up with scripts
Connecting to a server
Version 1 --
ping
Version 2 --
SSH
Version 3 --
MySQL/MariaDB
Summary
Chapter 3: Conditions Attached
Simple decision paths using command-line lists
Verifying user input with lists
Using the test shell builtin
Testing strings
Testing integers
Testing file types. Creating conditional statements using ifExtending if with else
More conditions with elif
Creating the backup2.sh using elif
Using case statements
Recipe --
building a front-end with grep
Summary
Chapter 4: Creating Code Snippets
Abbreviations
Using code snippets
Bringing color to the terminal
Summary
Chapter 5: Alternative Syntax
Recapping test
Testing files
Adding logic
Square brackets as not seen before
Providing parameter defaults
Variables
Special parameters
Setting defaults
When in doubt --
Quote!
Advanced test using [[
Whitespace
Other advanced features. Pattern matchingRegular expressions
Regular expression script
Arithmetic operations using ((
Simple math
Parameter manipulation
Standard arithmetic tests
Summary
Chapter 6: Iterating with Loops
For loops
Controlling the loop
While loops and until loops
Reading input from files
Creating operator menus
Summary
Chapter 7: Creating Building Blocks with Functions
Introducing functions
Passing parameters to functions
Returning values from functions
Using functions in menus
Summary
Chapter 8: Introducing sed
Using grep to display text. Displaying received data on an interfaceDisplaying user account data
Listing the number of CPUs in a system
Parsing CSV files
The CSV file
Isolating catalog entries
Using regular expressions
Working with alternate spellings
How many words have four consecutive vowels?
RE anchors
Understanding the basics of sed
Substituting command
Editing the file
Summary
Chapter 9: Automating Apache Virtual Hosts
Apache name-based Virtual Hosts
Creating the Virtual Hosts template
First steps
Isolating lines
sed script files
Automating Virtual Host creation.