Version control with Git: Glossary

Key Points

Introduction
  • Git is a version control tool; one of many.

  • GitHub is a repository hosting service; one of many.

  • Use version control to store versions neatly, restore previous versions, understand what happened (and why), and always know which is the current version.

Tracking changes with a local repository
  • git init initializes a new repository

  • git status shows the status of a repository

  • Files can be stored in a project’s working directory (which users see), the staging area (where the next commit is being built up) and the local repository (where commits are permanently recorded)

  • git add puts files in the staging area

  • git commit saves the staged content as a new commit in the local repository

  • Always write a log message when committing changes

Looking at history and differences
  • git log shows the commit history

  • git diff displays differences between commits

  • git checkout recovers old versions of files

  • HEAD points to the commit you have checked out

  • master points to the tip of the master branch

Commit advice
  • Commit messages explain why changes were made, so make them clear and concise

  • Follow conventions to give a history that is both useful, and easy to read

  • Only commit files which can’t be automatically recreated

Branching
  • git branch creates a new branch

  • Use feature branches for new ideas and fixes, before merging into master

  • merging does not delete any branches

Undoing changes
  • git checkout <file> discards unstaged changes

  • git commit --amend allows you to edit the last commit

  • git revert undoes a commit, preserving history

  • git reset undoes a commit by deleting history

Rebasing
  • rebase applies your changes on top of a new base (parent) commit

  • rebasing rewrites history

Working from multiple locations with a remote repository
  • Git is the version control system: GitHub is a remote repositories provider.

  • git clone to make a local copy of a remote repository

  • git push to send local changes to remote repository

Collaborating with a remote repository
  • git pull to integrate remote changes into local copy of repository

Pull Requests
  • A fork is a git clone into your (GitHub) account

  • A pull request asks the owner of a repository to incorporate your changes

Git hints and tips
  • List files to ignore by committing a .gitignore file

  • Selectively stage changes to files using git add --patch

  • Configure a visual diff tool and use git difftool to view changes

Conclusions and further information
  • Use version control whenever possible

Glossary

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