Git

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Git is a version management tool used by our team to keep track of code changes. Specifically, our repos are hosted on GitHub. On our GitHub, you will find code for various projects and competitions.

What is Git?

• Version Control System (VCS) for tracking changes in files
• Work independently on different features
• Merge your code with everyone else’s code
• Visit or revert back to any previous version at any time

What is GitHub?

• Online platform for hosting VCS
• Collaborate on a repository
• Intuitive UI
• Additional features for software development (issues, projects, etc.)

Repositories

• Essentially a specific folder (either remote or local) with version tracking
• Commits
  • A “checkpoint” that denotes a specific point in the repo
• Branches
  • Offshoot of the main code base with its own version history

Local vs. Remote Repository

Local Repository:

• Files stored on your computer drive.
• Your own “version” of the files.
• Changes here don’t affect the outside world

Remote Repository:

• Where you “push” or upload your code for review
• Anyone and everyone can see these changes
• Merged changes here are part of the latest release code

Git

Installation - Command Line

Linux (Debian/Ubuntu): sudo apt install git Linux (Fedora): sudo dnf install git or sudo yum install git Mac: https://git-scm.com/download/mac Windows: https://git-scm.com/download/win

Installation - GUIs

You will still need command line!

• GitHub Desktop
  • Windows/Mac: https://desktop.github.com/
  • Linux: https://github.com/shiftkey/desktop
• Tons more options
  • https://git-scm.com/downloads/guis

Basic Commands

• git add - Add files to Index, “stage” for commit
• git commit - Create a “checkpoint” in the repository
• git log - Show log of commits
• git diff - Show differences between commits
• git branch - Create or manage branches
• git checkout - Create and navigate between branches
• git switch - Switch to a different branch
• git rm - Remove files
• git merge - Merges other branch into currently checked out branch
• git status - Check status of working tree
• git push - Push local repository to remote repository
• git pull - Update local repo with the latest changes from remote repo

Need help with a git command?

Use git help [COMMAND]

Example Usage:

• Wanna know how to use git clone? Then, use git help clone

Note: git help can also be used as a standalone command or as git help --all to list the most common or all available commands, respectively

Commits

Commits create a snapshot of the current state of your code.

git add <file> git commit -m “YOUR COMMIT MESSAGE”

How to write commit messages: https://chris.beams.io/posts/git-commit/

Branching

Branches are a set of code changes that can operate without affecting the main codebase.

Essentially, a branch has a separate history from the main codebase.

git branch <branch_name> git checkout <branch_name>

To create a new branch, use git checkout -b “feature/branch_name”

Note: the “feature/” part is there as our naming system for our branches. When creating a new branch for our repos, use this syntax.

Pushing

Pushing updates the remote branch with the current commit on your local branch.

git push or git push origin master

If you’re working on a local checked out branch you’ll have to set your remote counterpart with git push --set-upstream-to origin <branch_name>

Merging

Merging unifies the code of two different branches.

git merge <other_branch>

Note that this will merge other_branch into the branch you’re currently on. Only do this after you’ve committed, pushed, and been approved for your current branch’s code.

Merge Conflicts

Sometimes the changes on two different branches are conflicting. Git doesn’t know how to decide between them, so you must choose manually.

Pulling

This is how you can update your local repo with the latest changes from the remote repo

git pull

Pulling will merge changes from the remote branch into your local branch.

This may happen automatically or could result in merge conflicts.

GitHub

Pull Requests

Pull requests are mainly for merging a remote branch into the master branch.

Leave comments, request reviews, make new commits until it’s ready.

Issues

Issues track problems/to-dos in a repository.

They can be given description, to do actions, and be assigned to specific people.

Projects

Project boards show what tasks need to be done, who is working on which tasks, and what has been completed.

Can be linked to address certain Issues!

More Resources

• Official Github documentation: https://docs.github.com/en
• More about VCS: https://www.atlassian.com/git/tutorials/what-is-version-control
• Visualizing Git, animated for each git command: https://onlywei.github.io/explain-git-with-d3/
• Interactive visual tutorial with animations: https://learngitbranching.js.org/
  • Level 1 on the Main and Remote categories should be sufficient
• How to write commit messages: https://chris.beams.io/posts/git-commit/