Introduction to using Git and GitHub for software development: Summary of Commands

Key Points

Why use a Version Control System?
  • Version control software refers to a type of program that records sets of changes made to files

  • VCS is a ubiquitous tool for software development

  • Tracking changes makes it easier to maintain neat and functional code

  • Tracking changes aids scientific reproducibility by providing a mechanism to recreate a particular state of your code base

  • VCS provides a viable mechanism for 100’s of people to work on the same set of files

  • VCS lets you undo mistakes and restore a code base to a previous working state

  • Git is the most widely used version control software

  • Using Git facilitates access to online tools for publication and collaboration

Committing and History
  • Setup Git with your details using git config --global user.name "FIRST_NAME LAST_NAME" and git config --global user.email "email@example.com"

  • A Git repository is the record of the history of a project and can be created with git init

  • Git records changes to files as commits

  • Git must be explicitly told which changes to include as part of commit (known as staging changes) with git stage [file]...

  • Staged changes can be stored in a commit with git commit -m "commit message"

  • You can check which files have been changed and/or staged with git status

  • You can see the full changes made to files with git diff for unstaged files and git diff --staged

  • The commit history of a repository can be checked with git log

  • The command git revert commit_ref creates a new commit which undoes the changes of the specified commit

  • The command git reset --soft HEAD^ removes the previous commit from the history

Sharing your code
  • Public repositories are open to anyone to use and contribute.

  • Private repositories are just for yourself or a reduced set of contributors.

  • README contains a description of the software and, often, some simplified installation instructions.

  • The LICENSE describes how the software must be distributed and used.

  • Using one of the OSI (open source initiative) licenses is recommended if the repository is public.

  • CONTRIBUTING describes how other users can help develop the software.

  • CITATION helps others to cite your software in their own papers.

  • GitHub can be used to set up a software repository, share your code and manage who can access it, and how.

Remote repositories
  • origin is typically the name of the remote repository used by GitHub.

  • Local and remote repositories are not identical, in general.

  • Local and remote repositories are not synchronized automatically.

  • push and pull commands only affect the branch currently checked out.

Using GitHub Issues
  • Issues are a feature of GitHub which let you track work in a repository.

  • GitHub provides functionality for referencing issues in comments

  • Task lists can be created to keep track of a list of issues

  • Formatting syntaxes, templates, and subscribing to issues help with communication

Using GUIs and IDEs
  • Knowing how to use Git from the command-line is useful for understanding concepts and as a fallback

  • Text editors and IDEs often have built-in Git support

  • GUIs are particularly useful for viewing the graph-like structure of a repository

  • It is worth taking time to explore other tools for Git so you can find a workflow that suits you

Summary of Commands

Action Command
Create a new repository git init

Glossary

git
A widely used implementation of a Version Control System