Book Image

Git: Mastering Version Control

By : Aske Olsson, Jakub Narębski, Ferdinando Santacroce, Rasmus Voss
Book Image

Git: Mastering Version Control

By: Aske Olsson, Jakub Narębski, Ferdinando Santacroce, Rasmus Voss

Overview of this book

Git is one of the most popular types of Distributed Version Control System. Since its inception, it has attracted skilled developers due to its robust, powerful, and reliable features. Like most powerful tools, Git can be hard to approach for the newcomers. However, this learning path will help you overcome this fear and become adept at all the basic and advanced tasks in Git. This course starts with an introduction to version control systems before you delve deeply into the essentials of Git. This serves as a primer for the topics to follow such as branching and merging, creating and managing a GitHub personal repository, and fork and pull requests. You'll also learn how to migrate from SVN using Git tools or TortoiseGit and migrate from other VCSs, concluding with a collection of resources, links, and appendices. As you progress on to the next module, you will learn how you can automate the usual Git processes by utilizing the hook system built into Git. It also covers advanced repository management, including different options to rewrite the history of a Git repository before you discover how you can work offline with Git, how to track what is going on behind the scenes, and how to use the stash for different purposes. Moving forward, you will gain deeper insights into Git's architecture, its underlying concepts, behavior, and best practices. It gives a quick implementation example of using Git for a collaborative development of a sample project to establish the foundation knowledge of Git operational tasks and concepts. By exploring advanced Git practices, you will attain a deeper understanding of Git’s behavior, allowing you to customize and extend existing recipes and write your own. This Learning Path is a blend of content, all packaged up keeping your journey in mind. It includes content from the following Packt products: • Git Essentials, Ferdinando Santacroce • Git Version Control Cookbook, Aske Olsson and Rasmus Voss • Mastering Git, Jakub Nar?bski
Table of Contents (36 chapters)
Git: Mastering Version Control
Credits
Preface
3
Git Fundamentals – Working Remotely
Bibliography
Index

Git references


We said that a Git repository can be imagined as an acyclic graph, where every node, the commit, has a parent and a unique SHA-1 identifier. But during the previous chapters, we even used some references such as the HEAD, branches, tags, and so on.

Git manages these references as files in the .git/refs repository folder:

If you open one of those files, you will find it inside the SHA-1 of the commit they are tied to. As you can see, there are subfolders for tags and branches (called heads).

Symbolic references

The HEAD file instead is located in the .git folder, as shown in the following screenshot:

HEAD is a symbolic reference; symbolic references are references that point to other references, using the ref: <reference> syntax. In this case, the HEAD is currently pointing to the master branch; if you check out another branch, you will see the file's content change, as shown in the following screenshot:

Ancestry references

In Git you often need to reference the past (for example...