Git

Cyriel Mallart
Ludovic Deneuville
Rémi Pépin

Introduction

  • What is Git?
    • Version control system: tracks changes in code, allows collaboration, and helps manage project history.
  • Why use Git?
    • Work on different features simultaneously, revert mistakes, and collaborate efficiently.

How Git Works

Local vs. Remote Repositories

  • Local: Your personal copy of the project on your machine.
  • Remote: A shared repository hosted on a server (e.g., GitHub, GitLab).

Basic Workflow

  1. Make changes locally.
  2. Stage changes.
  3. Commit changes to your local repository.
  4. Push changes to the remote repository (or pull changes from it).

How Git Works

Git Workflow Diagram

Git Workflow Diagram

Setting Up Git

  • Configure Git (one-time setup):

    git config --global user.name "Your Name"
git config --global user.email "your.email@example.com"

  • Initialize a Repository:

    git init
    • This creates a hidden .git folder in your project directory.

Basic Git Commands

Check Status

  • See which files are modified, staged, or untracked:

    git status

Stage Changes

  • Add files to the staging area:

    git add <file>          # Stage a specific file
git add .               # Stage all changes

Commit Changes

  • Save staged changes to your local repository:

    git commit -m "Your descriptive commit message"

View History

  • See the commit history:

    git log

Connect to a Remote Repository

  • Add a remote repository (e.g., GitHub):

    git remote add origin <remote-repository-url>

  • Push changes to the remote repository:

    git push -u origin main   # Push to the 'main' branch

  • Pull changes from the remote repository:

    git pull origin main      # Pull the latest changes

Clone a Repository

  • Copy a remote repository to your local machine:

    git clone <remote-repository-url>

Branching Basics

Why use branches?

  • Work on features or fixes without affecting the main codebase.
  • Best practice for working as a team : 1 branch per “big part”

Branching Basics

  • Create a Branch:

    git branch <branch-name>         # Create a new branch
git checkout <branch-name>       # Switch to the branch
git checkout -b <branch-name>    # Create and switch to the branch

  • Merge a Branch:

    git checkout main                 # Switch to the main branch
git merge <branch-name>           # Merge the branch into main

Common Mistakes and Fixes

  • Oh no I messed up:
    • Step 1 : do not panic
    • Step 2 : READ the error message / git status and check history
    • Step 2 : remember you can always go back to a previous version
    • Step 3 : Google is your friend

Common Mistakes and Fixes

Undo Changes:

  • Undo a commit (keep changes): bash git reset --soft HEAD~1
  • Discard unstaged changes: bash git restore <file>

Common Mistakes and Fixes

Resolve Merge Conflicts:

If Git reports conflicts during a merge, manually edit the conflicting files, then:

git add <resolved-file>
git commit

Wrap-Up

Recap:

  • Git tracks changes, allows collaboration, and manages project history.
  • Use git add, git commit, git push, and git pull.
  • Branches help manage features and fixes separately.

Wrap-Up

Practice makes perfect:

  • Experiment with Git commands during the lab work (do NOT designate 1 “Git expert”)
  • Solve issues by communicating about what happened

Resources