What this book covers
Chapter 1, Introduction to PowerShell – What It Is and How to Get It, explains what PowerShell 7 is, describes its uses, and how it differs from Windows PowerShell. It describes how to get it, how to install it, and how to run it, explaining the difference between User and Administrator mode. It describes how to run cmdlets and how to get help in PowerShell.
Chapter 2, Exploring PowerShell Cmdlets and Syntax, focuses on how PowerShell cmdlets work, approved verbs, parameters, how to find new cmdlets with the PowerShell Gallery and elsewhere on the internet, and finally, how to work interactively with PowerShell.
Chapter 3, The PowerShell Pipeline – How to String Cmdlets Together, covers how the PowerShell pipeline is one of the most important concepts in PowerShell and is quite different from how pipelines work in Bash and the Command Prompt. This chapter will show you how to successfully chain cmdlets together in a pipeline to produce useful outcomes. It will talk about filtering, output, how the pipeline works, and why it sometimes doesn’t!
Chapter 4, PowerShell Variables and Data Structures, is an introduction to variables and the different types they may be, integers, floats, and how these are all objects. We’ll explore the object concept and why it is important. We’ll look at data structures as collections of objects, then arrays and hash tables, and finish with splatting.
Chapter 5, PowerShell Control Flow – Conditionals and Loops, covers conditional flow (*IF* this, *THEN* that) and loops, including for, each, and while loops. Often, you won’t want to process cmdlets in a linear fashion – you’ll want to only do something if another thing is true or do something for all the objects in a pipeline. Control flow is how we do this. This chapter will also move us on from running interactive cmdlets to writing very simple scripts in VS Code.
Chapter 6, PowerShell and Files – Reading, Writing, and Manipulating Data, shows you how to take data from common file types such as CSV and TXT files and manipulate it, as well as how to send your output to files, alleviating the tedium of having to read output off a screen and typing loads of it in. We’ll also cover how to output to HTML, which is great for creating formatted reports and live data in web-hosted dashboards.
Chapter 7, PowerShell and the Web – HTTP, REST, and JSON, explores PowerShell and the web. Files are all very well, but a lot of cloud administration requires the manipulation of data from the internet; to do this, we’ll need to be able to manipulate the most common internet data type, JSON. We’ll also want to manipulate cloud services, for which we will need to be able to use REST API calls. This chapter will walk through that.
Chapter 8, Writing Our First Script – Turning Simple Cmdlets into Reusable Code, focuses on how we can turn lines of code into a script that we can save and run over and over again. We’ve covered how to write a few lines of code in an IDE. How do we turn that into something that we would want to run repeatedly, and make it useful for other people to run?
Chapter 9, Don’t Repeat Yourself – Functions and Scriptblocks, introduces you to functions in PowerShell as well as script blocks and lambdas. When writing a script, we will frequently find ourselves running the same few lines of code. Turning them into functions within the script means we only need to write it once, just calling it every time we need it.
Chapter 10, Error Handling – Oh No! It’s Gone Wrong!, covers the two main types of errors that we’re likely to encounter – problems that our code encounters and problems with our code. In the first part of the chapter, we’ll define what an error is, how we can set PowerShell up to handle errors gracefully, and how we can make sense of them. In the second part, we’ll look at how we can identify problems with our code and use VS Code for debugging.
Chapter 11, Creating Our First Module, examines how to turn functions and scripts into a module that can be reused, easily distributed, and incorporated into other scripts. Now we have a script, containing a set of functions, the next step is to turn that into a tool that others can use for themselves.
Chapter 12, Securing PowerShell, delves into how to secure our PowerShell scripts and modules and run them in a secure fashion. PowerShell is a very powerful tool, and with great power comes great responsibility. The chapter will cover script execution policies, code signing, AppLocker, and some of the other security features.
Chapter 13, Working with PowerShell 7 and Windows, explores how to use PowerShell 7 on Windows, when we will need to use PowerShell 5.1, how to interact with remote machines using WinRM, how to manage machines with CIM, and basic interaction with Windows features such as storage. PowerShell originated on Windows, and PowerShell 7 is intended to eventually replace Windows PowerShell, but we’re not there yet.
Chapter 14, PowerShell 7 for Linux and macOS, explains how to install PowerShell on Linux, how it differs from running PowerShell on Windows, and how to use VS Code on Linux. It explains remoting with OpenSSH, how to run scripts, and some common administration tasks. It finishes with a section on installing and running PowerShell and VS Code on macOS.
Chapter 15, PowerShell 7 and the Raspberry Pi, examines how to get started with PowerShell on Raspberry Pi, allowing us to do home automation, maker projects and more. It covers installing PowerShell and VS Code, connecting to the Pi, and running scripts. Raspberry Pi is everybody’s favorite single board computer, and we can transfer our PowerShell skills to our Pi stable.
Chapter 16, Working with PowerShell and .NET, delves into .NET, which is the developer platform that PowerShell 7 is built on; it’s free, open source, and works well with VS Code. There are lots of things we can’t do easily with PowerShell alone, but we can leverage .NET to achieve them. Familiarity with .NET is an essential skill for every advanced PowerShell coder, and this chapter will help you get there.
