Git Fundamentals, Object Model (Blobs, Trees, Commits), and Staging

⚡ Quick Dive

Essential Git Command Cheat Sheet

# Initialize & inspect
git init
git status -s
git log --oneline --graph --all

# Staging & commits
git add -A
git commit -m "feat: implement user authentication"

# Remote synchronization
git remote -v
git push -u origin main
git pull --rebase origin main

📖 Extended Guide

1. The Git Object Model & .git Anatomy

Git is a content-addressable key-value store under .git/objects/:

  • Blob: Stores pure file data without filenames or permissions.
  • Tree: Stores directory hierarchies, file names, and pointers to blobs or sub-trees.
  • Commit: Points to a root tree, parent commit hashes, author metadata, and message.
  • Tag: Permanent cryptographic pointer to a specific commit.
[ Commit: a1b2c3d ] ──► [ Tree: root ] ──┬──► [ Blob: main.go ]
         │                                └──► [ Tree: internal ] ──► [ Blob: auth.go ]
         ▼
[ Parent Commit: 9z8y7x ]

1. Setting Up Git

  • Before you start using Git, configure your identity:
git config --global user.name "Your Name"
git config --global user.email "your.email@example.com"
  • Check your configuration:
git config --list

2. Working with a Repository

  • Clone a Repository
git clone <repository-url>
  • Check Repository Status
git status
  • Add Files to Staging
git add <file-name>
# Or add all changes
git add .
  • Commit Changes
git commit -m "Your commit message"

3. Branching and Merging

  • Create a New Branch
git branch <branch-name>
  • Switch to a Branch
git checkout <branch-name>
  • Create and Switch to a Branch
git checkout -b <branch-name>
  • Merge Branches
git merge <branch-name>

4. Syncing with Remote

  • Push Changes
git push origin <branch-name>
  • Pull Changes
git pull origin <branch-name>
  • Set Remote Repository
git remote add origin <repository-url>

5. Undoing Changes

  • Discard Unstaged Changes
git checkout -- <file-name>
  • Unstage Changes
git reset <file-name>
  • Undo the Last Commit (Keep Changes)
git reset --soft HEAD~1
  • Undo the Last Commit (Discard Changes)
git reset --hard HEAD~1

6. Viewing Logs and History

  • Show Commit History
git log
  • Show Changes in Commit History
git log -p
  • Show Graphical History
git log --oneline --graph --decorate --all

Git Cheatsheet

Command Description
git config --global Configure global username/email
git init Initialize a repository
git clone <url> Clone a repository
git status Show the working directory status
git add <file> / git add . Add file(s) to the staging area
git commit -m "<message>" Commit staged changes
git branch List branches
git branch <branch-name> Create a new branch
git checkout <branch-name> Switch to a branch
git checkout -b <branch-name> Create and switch to a branch
git merge <branch-name> Merge a branch into the current branch
git pull origin <branch-name> Pull updates from a remote branch
git push origin <branch-name> Push changes to a remote branch
git reset <file> Unstage a file
git reset --soft HEAD~1 Undo last commit but keep changes
git reset --hard HEAD~1 Undo last commit and discard changes
git log Show commit history
git log --oneline --graph --all Show graphical commit history

For more advanced Git commands, consult the Git documentation.

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