Git Essentials

By Ferdinando Santacroce

About This Book

• Master all the basic concepts of Git to protect your code and make it easier to evolve
• Use Git proficiently, and learn how to resolve day-by-day tasks easily
• A step-by-step guide, packed with examples to help you learn and work with Git internals

Who This Book Is For

If you are a software developer with little or no experience of versioning systems, or are familiar with other centralized versioning systems, then this book is for you. If you have some experience working with command lines or using Linux admin or just using Unix and want to know more about Git, then this book is ideal for you.

• Language: English
• Publisher: Packt Publishing
• Release date: Apr 28, 2015
• ISBN: 9781785287275

Book preview

Table of Contents

Git Essentials

Credits

Foreword

Foreword

Foreword

About the Author

About the Reviewers

www.PacktPub.com

Support files, eBooks, discount offers, and more

Why subscribe?

Free access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Errata

Piracy

Questions

1. Getting Started with Git

Installing Git

Running our first Git command

Setting up a new repository

Adding a file

Commit the added file

Modify a committed file

Summary

2. Git Fundamentals – Working Locally

Repository structure and file status life cycle

The working directory

File statuses

The staging area

Unstaging a file

The time metaphor

The past

The present

The future

Working with repositories

Unstaging a file

Viewing the history

Anatomy of a commit

The commit snapshot

The commit hash

Author, e-mail, and date

Commit messages

Committing a bunch of files

Ignoring some files and folders by default

Highlighting an important commit – Git tags

Taking another way – Git branching

Anatomy of branches

Looking at the current branches

Creating a new branch

Switching from branch to branch

Understanding what happens under the hood

A bird's eye view to branches

Typing is boring – Git aliases

Merging branches

Merge is not the end of the branch

Exercises

Exercise 2.1

What you will learn

Scenario

Results

Exercise 2.2

What you will learn

Scenario

Results

Deal with branches' modifications

Diffing branches

Using a visual diff tool

Resolving merge conflicts

Edit collisions

Resolving a removed file conflict

Keeping the edited file

Resolving conflicts by removing the file

Stashing

Summary

3. Git Fundamentals – Working Remotely

Working with remotes

Setting up a new GitHub account

Cloning a repository

Uploading modifications to remotes

What do I send to the remote when I push?

Pushing a new branch to the remote

The origin

Tracking branches

Downloading remote changes

Checking for modifications and downloading them

Applying downloaded changes

Going backward: publish a local repository to GitHub

Adding a remote to a local repository

Pushing a local branch to a remote repository

Social coding – collaborate using GitHub

Forking a repository

Submitting pull requests

Creating a pull request

Summary

4. Git Fundamentals – Niche Concepts, Configurations, and Commands

Dissecting the Git configuration

Configuration architecture

Configuration levels

System level

Global level

Repository level

Listing configurations

Editing configuration files manually

Setting up other environment configurations

Basic configurations

Typos autocorrection

Push default

Defining the default editor

Other configurations

Git aliases

Shortcuts to common commands

Creating commands

git unstage

git undo

git last

git difflast

Advanced aliases with external commands

Removing an alias

Aliasing the git command itself

Git references

Symbolic references

Ancestry references

The first parent

The second parent

World-wide techniques

Changing the last commit message

Tracing changes in a file

Cherry picking

Tricks

Bare repositories

Converting a regular repository to a bare one

Backup repositories

Archiving the repository

Bundling the repository

Summary

5. Obtaining the Most – Good Commits and Workflows

The art of committing

Building the right commit

Make only one change per commit

Split up features and tasks

Write commit messages before starting to code

Include the whole change in one commit

Describe the change, not what you have done

Don't be afraid to commit

Isolate meaningless commits

The perfect commit message

Writing a meaningful subject

Adding bulleted details lines, when needed

Tie other useful information

Special messages for releases

Conclusions

Adopting a workflow – a wise act

Centralized workflows

How they work

Feature branch workflow

GitFlow

The master branch

Hotfixes branches

The develop branch

The release branch

The feature branches

Conclusion

The GitHub flow

Anything in the master branch is deployable

Creating descriptive branches off of the master

Pushing to named branches constantly

Opening a pull request at any time

Merging only after a pull request review

Deploying immediately after review

Conclusions

Other workflows

The Linux kernel workflow

Summary

6. Migrating to Git

Before starting

Prerequisites

Working on a Subversion repository using Git

Creating a local Subversion repository

Checking out the Subversion repository with svn client

Cloning a Subversion repository from Git

Setting up a local Subversion server

Adding a tag and a branch

Committing a file to Subversion using Git as a client

Using Git with a Subversion repository

Migrating a Subversion repository

Retrieving the list of Subversion users

Cloning the Subversion repository

Preserving the ignored file list

Pushing to a local bare Git repository

Arranging branches and tags

Renaming the trunk branch to master

Converting Subversion tags to Git tags

Pushing the local repository to a remote

Comparing Git and Subversion commands

Summary

7. Git Resources

Git GUI clients

Windows

Git GUI

TortoiseGit

GitHub for Windows

Atlassian SourceTree

Cmder

Mac OS X

Linux

Building up a personal Git server with web interface

The SCM Manager

Learning Git in a visual manner

Git on the Internet

Git community on Google+

GitMinutes and Thomas Ferris Nicolaisen's blog

Ferdinando Santacroce's blog

Summary

Index

Git Essentials

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Git Essentials

Copyright © 2015 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: April 2015

Production reference: 1240415

Published by Packt Publishing Ltd.

Livery Place

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Birmingham B3 2PB, UK.

ISBN 978-1-78528-790-9

www.packtpub.com

Credits

Author

Ferdinando Santacroce

Reviewers

Fabrizio Donina

Giovanni Giorgi

Giovanni Toraldo

Commissioning Editor

Edward Gordon

Acquisition Editor

Meeta Rajani

Content Development Editor

Samantha Gonsalves

Technical Editor

Siddhesh Ghadi

Copy Editors

Hiral Bhat

Karuna Narayanan

Alpha Singh

Project Coordinator

Kinjal Bari

Proofreaders

Simran Bhogal

Safis Editing

Paul Hindle

Bernadette Watkins

Indexer

Tejal Daruwale Soni

Graphics

Jason Monteiro

Abhinash Sahu

Production Coordinator

Nilesh R. Mohite

Cover Work

Nilesh R. Mohite

Foreword

Occasionally, in the IT industry, some inventions are made whose value is far beyond their merely technical merit. Git is one of them.

Git is immensely faster and more convenient than SVN, CVS, and TFS. It is fast becoming the defacto standard mainly because there are no tools as powerful and versatile as it is; it is a wonderful masterpiece of code. Behind the success of Git lies much more: it is a revolutionary approach to writing code. Git houses an inherently collaborative component in its DNA. It is no coincidence then that the GitHub's tagline is Social Coding.

If Linus Torvalds goes down in history, it will perhaps be not only for Linux and his genius in writing C, but above all, for the social impact that Git has had on the IT community. Just like the invention of the Web and HTTP have enabled humanity to build a network of communication and collaboration previously unthinkable, Git is the very tool that enables us to transform code development into a social activity. As a matter of fact, Git has started a new era in IT.

Git is also a very well documented tool. If you want to learn the syntax of its 155 commands, you don't need this book; the man pages, which are available for free on the web, are certainly more exhaustive.

However, the heart of Git does not lie in the list of its command options. Just like reading the syntax of the class and interface keywords will hardly make you grasp the deeper meaning of object-oriented programming, in the same way, the essence of Git won't emerge easily from its man pages.

The hardest part of Git is the paradigm shift that it requires. Honestly, very few books that I've read are able to explain Git and the universe that revolves around it, in a simpler way than the one you're holding in your hands.

This book covers not only all the main topics you can find on the man pages with simplicity and synthesis (such as the commit, stash, rebase, and management of remote), but also has the merit of being one of the few books to give you a 360-degree overview of the ecosystem that every pragmatic programmer should master. It explains how to set up a local server, teaches you the theory and practice behind GitHub and pull requests in a simple and practical way, and even contains a step-by-step guide to migrate from SVN to Git.

Git Essentials has another merit: it is built like a huge tutorial, and is a step-by-step journey through the Git universe. It's not an academic paper; on the contrary, it's full of concrete examples, is written by a programmer, and targeted at other programmers.

It is a book that values code much more than words.

Arialdo Martini

Solutions Architect at Aduno Gruppe

Foreword

At the time of writing this (April 2015), Git has just crossed the historical 10th anniversary since its inception. It is crazy for me to think it's already been 10 years.

Owing not in a small part to the innovative concepts that Git and some earlier DVCS solutions brought about, a huge chunk of the modern software development world has been turned upside down due to it. Teams that have adopted it have been greatly empowered on many fronts.

You can branch off and start working on some experimental features without bothering your colleagues. You can also keep your stable branches stable and only merge completed features. Git will also allow you to explore an entire project