Master Git: From Basics to Advanced Branching, Remote Collaboration, and Conflict Resolution

1. What is Git?

Git is the most advanced distributed version control system in the world.

2. How Git Works

Git operates with four main areas:

Workspace – the working directory you see on your computer.

Index/Stage – the staging area.

Repository – the local .git directory that stores all history.

Remote – a repository hosted on another server.

3. SVN vs. Git

SVN is a centralized system that requires a network connection to the central server for every operation, while Git is distributed; each developer has a full copy of the repository and can work offline, pushing changes to others when needed.

4. Installing Git on Windows

Download and install msysgit (the Windows version of Git). After installation, run "Git Bash" from the Start menu. Configure your identity with:

git config --global user.name "Your Name"
git config --global user.email "[email protected]"

5. Basic Operations

Creating a Repository

Navigate to your project folder and run: git init This creates a hidden .git directory that tracks all changes.

Adding and Committing Files

Example with a readme.txt file:

git add readme.txt
git commit -m "Add initial readme"

Use git status to see untracked or modified files.

Viewing Changes

Show differences with:

git diff readme.txt

Version History

List commits with: git log For a concise one‑line view:

git log --pretty=oneline

Reverting Versions

Move the HEAD pointer back:

git reset --hard HEAD^   # one commit back
git reset --hard HEAD~100   # back 100 commits

Find a specific commit hash with git reflog and reset to it:

git reset --hard 6fcfc89

Understanding Workspace vs. Staging Area

Changes are first added to the staging area with git add, then committed to the repository with git commit. You can view the status at any time with git status.

Undoing Changes

Discard uncommitted modifications: git checkout -- readme.txt Use the same command for files you have already staged but then edited again.

Deleting Files

Remove a file from the working tree and stage the deletion:

git rm b.txt
git commit -m "Delete b.txt"

If you haven't committed yet, you can restore it with:

git checkout -- b.txt

6. Remote Repositories

After creating a GitHub account, generate an SSH key ( ssh-keygen -t rsa -C "[email protected]") and add the public key to GitHub.

Create a new repository on GitHub (e.g., testgit) and link it to your local repo:

git remote add origin https://github.com/youruser/testgit.git

Push the initial commit: git push -u origin master Future pushes are simply:

git push origin master

Cloning a Repository

To clone an existing remote repo:

git clone https://github.com/youruser/testgit2.git

7. Branch Management

Create and switch to a new branch: git checkout -b dev List branches with git branch. Merge a branch back into master:

git checkout master
git merge dev

If the merge is fast‑forward, Git simply moves the master pointer.

Delete a branch after merging:

git branch -d dev

Merge Strategies

Use --no-ff to force a merge commit and preserve branch history:

git merge --no-ff -m "Merge dev" dev

8. Handling Conflicts

When merging conflicting changes, Git marks the conflict with <<<<<<<, =======, and >>>>>>>. Edit the file to resolve, then commit.

9. Bug‑Fix Branches

Create a short‑lived branch for a bug (e.g., issue-404), fix the problem, merge back, and delete the branch.

10. Stashing Work in Progress

If you need to switch context without committing, stash your changes:

git stash
# later
git stash pop   # restores and removes the stash
# or
git stash apply   # restores without removing

11. Multi‑Developer Collaboration

Push your branch to the remote: git push origin dev Pull updates from others: git pull origin dev If the pull fails because the local branch isn’t tracking the remote, set the upstream: git branch --set-upstream-to=origin/dev dev Resolve any conflicts, commit, and push again.

12. Summary of Essential Commands

View branches: git branch Create branch: git branch name Switch branch: git checkout name Create & switch: git checkout -b name Merge: git merge name Delete branch: git branch -d name These commands form the core workflow for using Git effectively in software development.