Version control with Git

The collaborative development of PsyNet is underpinned by the version control system ‘Git’. Git is also used by the majority of open-source software projects across the world. It is a rather complex tool and can be legendarily frustrating for first-time users. However its functionality is indispensable in enabling multiple programmers to work on the same code-base simultaneously, each making their own modifications and feature implementations in their own workspaces, and progressively feeding the results into the common codebase.


Credit: XKCD, Creative Commons Attribution-NonCommercial 2.5 License.

You will have probably installed Git already as part of the PsyNet installation process. If not, you can install it with the following command. Assuming you’re using a Mac, and assuming you’ve already installed Homebrew:

brew install git

Git is a command-line tool. This means you work with it by entering text into the command-line (on Mac, this is the Terminal) application.


You use Git by writing various Git commands. Git commands always begin with the word ‘git’. For example:

git add README.txt
git commit -m "Added a README file"
git push

In the rest of this tutorial we’ll try to develop an understanding of the essential Git commands and how they are used when working with a software project. We’ll begin with an overview of essential concepts in Git, and will then move onto Git’s command-line syntax.