Why Version Control?

  • Version control records every meaningful change to your project.
  • Git’s three-step workflow is: edit → stage → commit.
  • Version control facilitates collaboration, provenance, and backup.

Configuring Git

  • git config writes and reads Git’s preference files.
  • Three levels exist: system, global, local; the closest level wins.
  • Setting your name and email globally ensures commits are attributed correctly.
  • Colour, editor, and autocorrect options improve usability.

Recording Changes Locally

  • git init turns a directory into a repository by creating .git.
  • git status gives you a report on your git repository.
  • Stage files with git add; record them permanently with git commit -m.
  • Use git diff to inspect unstaged or staged changes.
  • git log reveals the history; hashes uniquely identify commits.
  • Empty directories are not tracked—add a file such as .gitkeep.
  • git restore returns a file to a known state.

Working with Remote Repositories

  • A remote is a named reference to a repository hosted elsewhere.
  • git clone URL copies a remote repository and sets up origin.
  • Publish an existing repo with git remote add followed by git push -u origin <branch>.
  • git pull equals git fetch + git merge; use --rebase to avoid unnecessary merges.
  • A push may be rejected if your branch is behind; pull (or fetch & merge) then push again.

Using Git with a Graphical User Interface RStudio

  • Git GUIs offer a visual way to use Git—perfect for beginners and for visualising changes.
  • RStudio’s Git integration supports cloning, staging, committing, and pushing.
  • Always configure your name/email before making your first commit.
  • You can verify success by checking your changes online.

Collaborating

  • Git allows multiple collaboration models; shared access is fastest but requires trust.
  • GitLab permissions and protected branches must be configured for collaborators.
  • Always pull before pushing to avoid rejection.
  • Merge conflicts are normal and can be resolved with manual editing.

Exploring History

  • git log is used to inspect the commit history, with options for concise, graphical, or filtered views.
  • git show displays the details and changes of a specific commit or the content of a file at a past revision.
  • git diff compares changes between the working directory, staging area, and different commits.
  • git restore can discard unstaged changes, unstage changes, or restore files from previous commits.
  • RStudio provides a graphical interface for exploring Git history.
  • git blame helps identify who last modified each line of a file.

Ignoring Things

  • Use .gitignore to prevent tracking of unnecessary or sensitive files
  • Edit .gitignore early in your project to keep your history clean
  • Use .git/info/exclude for machine-specific ignores
  • Files already tracked by Git won’t be ignored retroactively