ADVANCED COMPUTING TOOLS
LABORATORY
Lab 3. Introduction to Git version control
Introduction
In this lab session you will become familiar with the basic Git workflow. You will learn to create and
manage a source code repository, hosted in GitHub, both through the web page interface and a desktop
client. In addition, if you have some spare time you will also have the opportunity to practice with the
command line.
Objectives
By the end of the session, the student should:
• Understand the importance of using a version control system in software development.
• Be comfortable with the GitHub flow.
1. Git using GitHub’s web interface
Start by signing up for a free account in GitHub (https://github.com). Once you have logged in,
complete the Hello World tutorial (https://guides.github.com/activities/hello-world) that will
guide you through your first steps with a distributed version control system.
2. Git with a GUI desktop client
Now that you know how to perform the most common operations, it is time to move to your computer.
Download and install the official GitHub desktop client for Windows from https://windows.github.com
(there is also a Mac version available at https://mac.github.com) and sign in with your username
and password. Afterwards, click on the plus sign in the upper left hand corner and select Clone to
download the hello-world repository to the directory of your choice (Figure 1).
Figure 1. Cloning a repository in GitHub for Windows.
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Academic year 2014/2015
ADVANCED COMPUTING TOOLS
LABORATORY
At this point, you should have a local copy of your project that you can freely edit, so go ahead
and do it! You can modify the content of README.md, create new folders inside the project’s folder, or
add files. For example, you could create a folder named MATLAB and include the code from Lab 2.
Remember to create a branch before editing! You do not want to break production code!
When you are done, go back to the desktop client and you should see something similar to Figure 2.
The Uncomitted changes section shows the modifications you made. Select the files you want to commit
(this is equivalent to adding them to the staging area), type a comment, and commit the changes.
Figure 2. Uncommited changes.
However, the files have not been synced to the GitHub server yet. To do so, click Publish in the
upper right hand corner (Figure 3). If the branch already existed in the server, the Sync button would
appear instead. You should now be able to see the updates in your browser.
Figure 3. Unsynced commit.
Finally, try to modify the same line of code in different ways both in the web interface and in your
local copy without syncing. When you try to sync, the desktop client should display a message stating
that it encoutered conflicts that need to be manually resolved before proceeding (Figure 4).
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Academic year 2014/2015
ADVANCED COMPUTING TOOLS
LABORATORY
Figure 4. Conflict error message.
Update the conflicting parts marked between “<<<<<<< HEAD” and “>>>>>>>” (Figure 5), commit the
changes, and sync. Congratulations, you have successfully solved your first merge conflict! You already
know all the fundamentals to continue experimenting with version control systems!
Figure 5. Merge conflict example.
3. Git through the command line (Optional)
Git was originally conceived to be used with a CLI (Command Line Interface). For this reason, many
everyday commands are run much faster through the terminal than with a GUI, and some complex
operations can still only be performed using the command line. If you have some time left, there is a
brief interactive tutorial at https://try.github.io where you can practice with the basic commands.
A more extensive Git cheat sheet can be downloaded at https://training.github.com/kit.
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