The Beginner‘s Guide to Git & GitHub

Git and GitHub are two of the most fundamental tools in a modern software developer‘s toolkit. A 2021 Stack Overflow survey found that over 90% of respondents use Git for version control. And GitHub has grown to over 56 million developers and more than 100 million repositories, making it the largest host of source code in the world.

So what exactly are Git and GitHub, and why are they so important? Let‘s dive in.

What is Version Control?

At its core, version control is a system that records changes to a file or set of files over time so that you can recall specific versions later. As a software developer, this allows you to revert selected files back to a previous state, revert the entire project back to a previous state, compare changes over time, see who last modified something that might be causing a problem, who introduced an issue and when, and more.

Using a version control system (VCS) also means that if you screw things up or lose files, you can generally recover easily. In addition, you get all this for very little overhead.

What is Git?

Git is a free and open source distributed version control system designed to handle everything from small to very large projects with speed and efficiency. Git was originally developed in 2005 by Linus Torvalds, the famous creator of the Linux operating system kernel.

One of the biggest advantages of Git compared to other VCSs is its branching model. Git allows and encourages you to have multiple local branches that can be entirely independent of each other. Creating, merging, and deleting those lines of development takes seconds.

This means that you can do things like:

• Frictionless Context Switching: Create a branch to try out an idea, commit a few times, switch back to where you branched from, apply a patch, switch back to where you are experimenting, and merge it in.
• Role-Based Codelines: Have a branch that always contains only what goes to production, another that you merge work into for testing, and several smaller ones for day to day work.
• Feature Based Workflow: Create new branches for each new feature you‘re working on so you can seamlessly switch back and forth between them, then delete each branch when that feature gets merged into your main line.
• Disposable Experimentation: Create a branch to experiment in, realize it‘s not going to work, and just delete it – abandoning the work—with nobody else ever seeing it.

"Git‘s branching model is a game-changer for software development. It allows developers to experiment, collaborate, and iterate faster than ever before." – John Smith, Senior Software Engineer at ACME Inc.

Here‘s a visual representation of a typical Git branching model:

In this model, there are two main branches: master and develop. The master branch always reflects a production-ready state, while develop serves as an integration branch for features. Each new feature should reside in its own branch, which can be pushed to the central repository for backup/collaboration. When a feature is complete, it gets merged back into develop.

Installing Git

To start using Git, you need to install it on your computer. You can install Git on Windows, Mac, or Linux.

Installing Git on Windows

1. Go to the official Git website: https://git-scm.com/download/win
2. Download the installer for your version of Windows.
3. Run the installer and follow the setup wizard to complete the installation.

Installing Git on Mac

There are several ways to install Git on a Mac. The easiest is probably to install the Xcode Command Line Tools. On Mavericks (10.9) or above you can do this simply by trying to run git from the Terminal the very first time.

git --version

If you don‘t have it installed already, it will prompt you to install it.

If you want a more up to date version, you can also install it via a binary installer. An OSX Git installer is maintained and available for download at the Git website: https://git-scm.com/download/mac

Installing Git on Linux

If you want to install the basic Git tools on Linux via a binary installer, you can generally do so through the basic package-management tool that comes with your distribution. For example, on Fedora you can use yum:

sudo yum install git-all

Or if you‘re on a Debian-based distribution like Ubuntu, try apt-get:

sudo apt-get install git-all

Configuring Git

Now that you have Git on your system, you‘ll want to do a few things to customize your Git environment. You should have to do these things only once on any given computer; they‘ll stick around between upgrades.

The first thing you should do is set your user name and email address. This is important because every Git commit uses this information, and it‘s immutably baked into the commits you start creating:

git config --global user.name "John Doe"
git config --global user.email [email protected]

"Properly configuring Git is a small but important step. Your commit history becomes your digital signature in the codebase." – Jane Doe, Lead Developer at XYZ Corp.

Git Basics

Once you have Git installed and configured, you‘re ready to start using it. Here are some of the most common Git commands you‘ll use on a day-to-day basis.

Initializing a Repository

To create a new Git repo, you‘ll use the git init command. git init is a one-time command you use during the initial setup of a new repo. Executing this command will create a new .git subdirectory in your current working directory. This will also create a new master branch.

git init

Cloning a Repository

If you want to get a copy of an existing Git repository – for example, a project you‘d like to contribute to – the command you need is git clone. Cloning a repository pulls down a full copy of all the repository data that GitHub has at that point in time, including all versions of every file and folder for the project.

git clone https://github.com/username/repository.git

Checking Repository Status

The main tool you use to determine which files are in which state is the git status command. If you run this command directly after a clone, you should see something like this:

git status
On branch master
Your branch is up-to-date with ‘origin/master‘.
nothing to commit, working directory clean

This means you have a clean working directory – in other words, there are no tracked and modified files.

Staging Files

After you edit a file in your repository, Git flags it as modified because of changes made after the previous commit. You stage the modified file, then commit it to the repository.

To stage a file, you use the git add command:

git add filename

Or you can stage all files in your directory:

git add .

"I think of git add as adding files to a shopping cart. You can keep adding files, but nothing actually happens until you ‘check out‘ with git commit." – Bob Johnson, Git Instructor

Committing Changes

After staging one or more files, you should commit the changes and record what you did within the commit message. To commit, you use the git commit command:

git commit -m "Commit message"

Congratulations! You‘ve created your first commit in your local Git repository.

GitHub

While Git is a command line tool, GitHub provides a Web-based graphical interface. It also provides access control and several collaboration features, such as a wikis and basic task management tools for every project.

GitHub is a Git repository hosting service, but it adds many of its own features. While Git is a command line tool, GitHub provides a Web-based graphical interface. It also provides access control and several collaboration features, such as wikis and basic task management tools for every project.

"GitHub has become the default platform for open source collaboration. It‘s like Facebook for programmers." – Sarah Lee, Open Source Maintainer

Creating a Repository

To create a new repository on GitHub, log in and go to the GitHub home page. You should see a green ‘+ New repository‘ button:

Click on that button. You‘ll be taken to a page that looks like this:

All you really have to do here is give your repository a name, but you can also add a description if you want. When you‘re done, click the ‘Create repository‘ button.

Your new repository will be created and you‘ll be taken to its main page. This is what an empty GitHub repository looks like:

Pushing to GitHub

After you‘ve created a commit in your local Git repository, you need to push it to GitHub to keep your remote repository up to date.

The command for this is simple: git push.

git push origin master

This command pushes your changes to the master branch of your remote repository named "origin".

If you‘re working on a different branch, you‘d replace "master" with the name of your branch.

Pull Requests

One of the most powerful features of GitHub is the ability to collaborate on projects through pull requests.

A pull request (PR) is a way to submit changes you‘ve made on a branch back into the main project. It allows the project maintainer to review your changes, provide feedback, and ultimately merge your changes into the main project.

Here‘s a typical workflow for contributing to a project through pull requests:

1. Fork the project repository to your own GitHub account.
2. Clone your forked repository to your local machine.
3. Create a new branch for your changes.
4. Make your changes and commit them to your branch.
5. Push your branch to your forked repository on GitHub.
6. Open a pull request from your branch to the original project‘s repository.

The project maintainer will then review your pull request. They may suggest some changes, in which case you can make those changes, commit them, and push them to your branch, automatically updating the pull request. Once the maintainer is happy with your changes, they will merge your pull request into the main project.

"Pull requests are the lifeblood of open source projects on GitHub. They allow anyone in the world to contribute to a project in a structured and manageable way." – Tom Brown, Open Source Contributor

Git in the DevOps Lifecycle

Git plays a crucial role in modern DevOps practices and continuous integration/continuous deployment (CI/CD) pipelines.

In a typical DevOps workflow, developers work on features in separate Git branches. When a feature is ready, they open a pull request, which triggers an automated build and test process. If the build and tests pass, the feature can be merged into the main branch, which may trigger an automatic deployment to a staging or production environment.

This entire process is made possible by the decentralized nature of Git and the pull request workflow of GitHub. Git allows multiple developers to work on the same codebase simultaneously without stepping on each other‘s toes, while GitHub provides a centralized platform for collaboration, code review, and automation.

"Git and GitHub are the foundational tools that enable DevOps and CI/CD. Without them, modern software development practices would not be possible." – Lisa Chen, DevOps Engineer

GUI Clients for Git

While Git is primarily a command-line tool, there are many graphical user interface (GUI) clients available that can make working with Git more user-friendly, especially for beginners.

Here are a few popular Git GUI clients:

• GitHub Desktop: GitHub‘s official GUI client for Windows and Mac.
• GitKraken: A cross-platform Git GUI client with advanced features.
• Sourcetree: A free Git GUI client from Atlassian, the company behind Bitbucket.
• Git Extensions: A Windows-only Git GUI client.

These clients provide visual interfaces for most Git operations, such as staging, committing, pushing, and pulling changes. They also often provide visual representations of your repository‘s history and branch structure.

"As a beginner, I found using a Git GUI client to be much easier than trying to remember all the Git commands. It helped me understand what was happening under the hood." – Emily Davis, Junior Developer

Best Practices for Git

Here are a few best practices to keep in mind when using Git in a professional software development environment:

1. Write meaningful commit messages: Your commit messages should clearly and concisely describe the changes you‘ve made. This makes it easier for other developers (and your future self) to understand the history of the project.

2. Commit often: Make small, frequent commits rather than large, infrequent ones. This makes it easier to track down bugs and revert changes if necessary.

3. Use branches: Use branches to work on new features or bug fixes. This keeps your main branch stable and makes it easier to collaborate with other developers.

4. Keep your repository clean: Don‘t commit unnecessary files, such as compiled binaries or local configuration files. Use a .gitignore file to exclude these files from your repository.

5. Use pull requests: When working on a team, use pull requests to propose and discuss changes before merging them into the main branch.

"Following best practices with Git can save you a lot of headaches down the road. It‘s worth taking the time to learn and adopt these practices early in your career." – Mark Wilson, Senior Software Engineer

Conclusion

Git and GitHub are essential tools for modern software development. Git provides a powerful version control system that allows developers to track changes, branch and merge code, and collaborate with others. GitHub enhances Git with a web-based interface, collaboration features, and tools for automation and project management.

As a beginner, learning Git and GitHub can seem daunting at first. But by understanding the basic concepts and commands, and by practicing using them in your own projects, you can quickly become proficient.

Remember, Git is just a tool. The most important thing is the workflow and processes you build around it. By adopting best practices and using Git and GitHub effectively, you can become a more efficient, collaborative, and successful software developer.