Version Control with Git

Instructors: Matthew Hamilton

Helpers:

General Information

This hands-on workshop will cover the principles of using Git for version control. We encourage you to help one another and to apply what you have learned to your own research problems. This tutorial is based on the principles of Software Carpentry, which aims to help researchers get their work done in less time and with less pain by teaching them basic research computing skills.

For more information on Software Carpentries, please see this paper "Best Practices for Scientific Computing".

Who: The course is aimed at graduate students and other researchers. You don't need to have any previous knowledge of the tools that will be presented at the workshop.

Where: . Get directions with OpenStreetMap or Google Maps.

When: . Add to your Google Calendar.

Requirements: Participants must bring a laptop with a Mac, Linux, or Windows operating system (not a tablet, Chromebook, etc.) that they have administrative privileges on. They should have a few specific software packages installed (listed below).

Code of Conduct: Everyone who participates is required to conform to the Code of Conduct. This document also outlines how to report an incident if needed.

Accessibility: We are committed to making this workshop accessible to everybody. The workshop organizers have checked that:

Materials will be provided in advance of the workshop and large-print handouts are available if needed by notifying the organizers in advance. If we can help making learning easier for you (e.g. sign-language interpreters, lactation facilities) please get in touch (using contact details below) and we will attempt to provide them.

Contact: Please email matt.hamilton@ed.ac.uk for more information.

Syllabus

Version Control with Git

  • Creating a Repository
  • Recording Changes to Files: add, commit, ...
  • Viewing Changes: status, diff, ...
  • Ignoring Files
  • Working on the Web: clone, pull, push, ...
  • Resolving Conflicts
  • Open Licenses
  • Where to Host Work, and Why
  • Reference...

Setup

To participate in you will need access to the software described below. In addition, you will need an up-to-date web browser.

We maintain a list of common issues that occur during installation as a reference for instructors that may be useful on the Configuration Problems and Solutions wiki page.

The Bash Shell

Bash is a commonly-used shell that gives you the power to do simple tasks more quickly.

Video Tutorial
  1. Download the Git for Windows installer.
  2. Run the installer and follow the steps below:
    1. Click on "Next" four times (two times if you've previously installed Git). You don't need to change anything in the Information, location, components, and start menu screens.
    2. Select "Use the nano editor by default" and click on "Next".
    3. Keep "Git from the command line and also from 3rd-party software" selected and click on "Next". If you forgot to do this programs that you need for the workshop will not work properly. If this happens rerun the installer and select the appropriate option.
    4. Click on "Next".
    5. Select "Use the native Windows Secure Channel library", and click "Next".
    6. Keep "Checkout Windows-style, commit Unix-style line endings" selected and click on "Next".
    7. Select "Use Windows' default console window" and click on "Next".
    8. Leave all three items selected, and click on "Next".
    9. Do not select the experimental option. Click "Install".
    10. Click on "Finish".
  3. If your "HOME" environment variable is not set (or you don't know what this is):
    1. Open command prompt (Open Start Menu then type cmd and press Enter)
    2. Type the following line into the command prompt window exactly as shown:

      setx HOME "%USERPROFILE%"

    3. Press Enter, you should see SUCCESS: Specified value was saved.
    4. Quit command prompt by typing exit then pressing Enter

This will provide you with both Git and Bash in the Git Bash program.

The default shell in all versions of macOS is Bash, so no need to install anything. You access Bash from the Terminal (found in /Applications/Utilities). See the Git installation video tutorial for an example on how to open the Terminal. You may want to keep Terminal in your dock for this workshop.

The default shell is usually Bash, but if your machine is set up differently you can run it by opening a terminal and typing bash. There is no need to install anything.

Git

Git is a version control system that lets you track who made changes to what when and has options for easily updating a shared or public version of your code on github.com. You will need a supported web browser.

You will need an account at github.com for parts of the Git lesson. Basic GitHub accounts are free. We encourage you to create a GitHub account if you don't have one already. Please consider what personal information you'd like to reveal. For example, you may want to review these instructions for keeping your email address private provided at GitHub.

GitHub Desktop App

As a solo developer who wishes to version control, you will likely not need more than the GitHub Desktop App. We will be using this app to begin with, so follow the instructions for installing the app

Git should be installed on your computer as part of your Bash install (described above).

Please open the Terminal app, type git --version and press Enter/Return. If it's not installed already, follow the instructions to Install the "command line developer tools". Don't click "Get Xcode", because that will take too long and is not necessary for our Git lesson. After installing these tools, there won't be anything in your /Applications folder, as they and Git are command line programs. For older versions of OS X (10.5-10.8) use the most recent available installer labelled "snow-leopard" available here. Because this installer is not signed by the developer, you may have to right click (control click) on the .pkg file, click Open, and click Open in the pop-up dialog. You can watch a video tutorial about this case.

If Git is not already available on your machine you can try to install it via your distro's package manager. For Debian/Ubuntu run sudo apt-get install git and for Fedora run sudo dnf install git.

Text Editor

When you're writing code, it's nice to have a text editor that is optimized for writing code, with features like automatic color-coding of key words. The default text editor on macOS and Linux is usually set to Vim, which is not famous for being intuitive. If you accidentally find yourself stuck in it, hit the Esc key, followed by :+Q+! (colon, lower-case 'q', exclamation mark), then hitting Return to return to the shell.

Atom

For this session we recommend installing Atom as it is a versatile text editor with syntax highlighting available for most programming languages.

nano is a basic editor and the default that instructors use in the workshop. It is installed along with Git.

Others editors that you can use are Notepad++ or Sublime Text. Be aware that you must add its installation directory to your system path. Please ask your instructor to help you do this.

nano is a basic editor and the default that instructors use in the workshop. See the Git installation video tutorial for an example on how to open nano. It should be pre-installed.

Others editors that you can use are BBEdit or Sublime Text.

nano is a basic editor and the default that instructors use in the workshop. It should be pre-installed.

Others editors that you can use are Gedit, Kate or Sublime Text.