"Begin at the beginning," the King said gravely, "and go on till you come to the end, then stop." – Alice in Wonderland

In this book, we will cover Git from the very beginning all the way through to advanced topics. No experience with Git is expected. Though if you have been using Git, you'll probably want to skim the initial chapters. Git is arguably the most popular version control system in the world, but this raises the question: "What is version control?"

Before version control, I would code a bit and then when I became afraid of losing that code, I would make a backup of my directory. This is slow, inefficient, takes up a lot of disk space, and is very hard to share with others.

A Version Control System (VCS) does all this work for you (and more) and does so in a way that is fast, efficient, and takes up a minimum of disk space. One of the fastest and most efficient is Git, although there are others. This book will not spend a lot of time convincing you that Git is better than the others. First, the market has spoken, and Git prevails. Second, if you've purchased this book, you've already decided. And if you haven't already purchased this book, go do so. I'll wait here.

In order to demonstrate the use of Git, we need to have a small program that we can evolve. The code examples are given in C#, but they are so simple that you'll be able to follow them regardless of your experience with the language. For example, if you can figure out what this does, you're all set.

public class Program
{
    public void PrintHello()
    {
        Console.WriteLine("Hello World!");
    }
}

This code declares a class (don't worry about what that is) named Program. Inside that class is a method (function) called PrintHello that prints Hello World to the console (your screen).

This is about as complex as it gets, and I'll explain each code snippet as we go.

In July of 2005, after just a few month's work, Linus Torvalds, the genius behind Linux, released Git to meet his own needs, the needs of the Linux community, and eventually, the rest of us. The goal of Git was to be fast and efficient. It succeeded.

While most VCSes at the time were centralized (all the files were kept on a big server), Git uses a distributed system, in which everyone has their own repository. Technically, no central server is required for Git, although if you are working in a team, a central place for sharing code is convenient. But the huge difference is that with Git, the vast majority of your interactions with the VCS are local – right there on your disk.

There are a number of easily confused terms (such as Git versus GitHub) and there are many tools for working with Git – from the command line to Graphical User Interface (GUI) tools. This section will review some of these options.

GitHub, et al.

There are many services that allow you to create shared "repositories" (the location of all the versions of your program). The most famous and popular are GitHub and Microsoft's Azure, as well as BitBucket and GitLab. Azure is a very powerful system for DevOps, while GitHub is a very straightforward way to host your program. We'll be using GitHub in this book. (Recently, Microsoft acquired GitHub for $7.5 billion in stock – and made a huge commitment to GitHub, open source and, of course, to Git.)

The very first thing you need to do is to install Git on your computer. The official Git site states that "even if Git is already installed on your computer, it is probably a good idea to reinstall to update to the latest version."

Getting Git on Windows

There are also a few ways in which to install Git on Windows. I recommend using the official build. The most recent one is available from the Git website: https://git-scm.com/download/win.

Another way to get Git, and to kill two birds with one stone, is to download and install GitHub Desktop. The installer will also install a command-line version of Git. You can get it at https://desktop.github.com/:

Figure 1.6: Obtaining GitHub Desktop

This book will show its demonstrations on Windows 10, using Git version 2.30.0.windows.2, but the examples should work with just about any version of Git.

Getting Git on a Mac

There are several ways to install Git on a Mac. The easiest is probably...

We'll look at configuring Git to personalize throughout this book, but for now, let's add your name and email address so that every entry into Git is stamped appropriately. Enter the command-line command:

git config --global --edit

This will bring up your editor. Find or create the [user] section and add the following:

[user]
name = Jesse Liberty
email = jesseliberty@gmail.com

You will probably want to use your own name and email address.

There are other entries in the config file. Ignore them for now and save and close the file.

In Visual Studio for Windows, click on the Git menu and a dialog box will open. On the first tab, enter your username and email address:

Figure 1.8: Setting Git options in Visual Studio

To configure GitHub Desktop, you'll need an account on GitHub. We'll cover that in the next chapter. Once you do have an account, go to File | Options, select the Accounts tab, and then click on Sign in:

Figure 1.9: Setting up GitHub Desktop

In this chapter you saw an introduction to the book, listing what is in each chapter. You also saw a quick history of version control and of Git itself.

Next, we took a look at downloading the environments you'll need to follow along: Visual Studio 2019, GitHub Desktop, and PowerShell as your command line. All of these can be obtained for free.

Once the software was downloaded, we looked at how to set up Git, and how to set up the tools we'll be using.