Version control with Git and GitHub

1. Please sit near the front
2. Open the notes at http://gcapes.github.io/git-course/
3. Sign up for a GitHub account
4. Attendance is recorded using a feedback form; there is no sign-in sheet
5. You can use Windows or Linux on the training PCs

Research-related IT services

• Described on IT Services website
• Announcements given via Research IT News
• Training courses teaching computing skills for Research
• General guidance and advice about research software
• Access to specialist support and consultancy e.g. code reviews
• Access to HPC systems
• Full list of services on offer
• For help and support, use the Support Portal

Housekeeping

• Fire exit
• Toilets
• Course timing
  • 09:30 – 12:00 Morning session
  • 12:00 – 13:00 Lunch
  • 13:00 – 16:00 Afternoon session

Teaching methods

• Interactive, workshop-style course
  • Code along with the examples
  • Test your understanding in the exercises
• Course notes
  • All examples and exercises are in the notes
  • Slides will remain online after the course

Getting help

• Sticky notes
  • Used for getting help and giving real-time feedback
  • Green = OK, ready to continue
  • Red = too fast, don’t understand, computer says no etc
• Please interrupt me to ask questions
• Peer learning
  • During exercises, please help each other as required
  • Please try to be quiet during worked examples so everyone can hear

What is a version control system?

• Version control is a piece of software which allows you to record and preserve the history of changes made to directories and files.
• If you mess things up, you can retrieve an earlier version of your project.

Storing versions without VCS

• Save a copy elsewhere?
• Save with a different name?
• How do you name different versions?
• What’s different between them?
• Many of copies of nearly-identical but critically different files.

Why use version control

To store versions properly

• VCS treats files as one project - one current version on disk, previous versions and variations are saved in a repository
• VCS starts with a base version of the project, and only saves the subsequent changes you make
• In order to save a new revision, a commit message is required, which explains why the changes were made.

Changes are saved sequentially

Different versions can be saved

Multiple versions can be merged

Why use version control?

• Restore previous versions
• Understand what happened
• Backup
• Collaboration

Before we get started

• Example scenario
• Text files vs binary files
• Git vs GitHub

Open the notes

https://gcapes.github.io/git-course

Why learn the commands?

The staging area

Checking out a previous commit: “detached HEAD”

Exercise 1

Create your own repo

http://gcapes.github.io/git-course/03-history

Branches

Three exercises on branching

http://gcapes.github.io/git-course/05-branching/

Revert

Create a new commit

Reset

Delete commit(s)

Exercises on remote collaboration

https://gcapes.github.io/git-course/09-remote-collaboration

Feedback form = attendance record

Rebasing

Merge vs rebase

Standard merge

Rebase onto master

(FF) merge after rebase

Forks and Pull Requests

Send me a PR!

http://gcapes.github.io/git-course/11-pull-requests/#exercise