Git Theory and Practical

Understand Git Concepts

CVCS Centralized Versioning System

A centralized version control system (VCS) uses a single, central repository to store all file versions and their change history. Team members have their own working copies, but all modifications are ultimately committed to this central server. This facilitates collaboration by providing a single source of truth, but it also creates a single point of failure. Examples include Subversion (SVN) and CVS.

DVCS - Decentralized Version Control System

In a Decentralized Version Control System (DVCS), every user has a complete copy of the repository, including its entire history. This eliminates the reliance on a central server, allowing for offline work and greater flexibility. Changes are shared between repositories as needed. Popular examples include Git and Mercurial.

What is Git?

Git is like a super-powered tracking system for your files and the changes you make to them over time. Imagine it as a special folder that remembers every version of your work, allowing you to go back to any previous stage if needed.  

Here’s what makes Git special:

• Keeps a detailed history: Git meticulously records every change you make to your files, who made it, and when. This history helps you understand how your project evolved.  
• Branching and merging: Git allows you to create separate branches, like alternate timelines, to experiment with new features or try different ideas without affecting the main project. You can then merge these branches back into the main project when you’re ready.  
• Collaboration made easy: Git is designed for teamwork. Multiple people can work on the same project simultaneously, and Git helps manage and integrate everyone’s contributions smoothly.  
• Offline access: You have the entire project history on your computer, so you can work even without an internet connection.  
• Popular and widely used: Git is the most popular version control system in the world, used by countless developers and companies.  

History of Git

Git was created by Linus Torvalds, the famous creator of the Linux operating system, in 2005. He needed a better tool to manage the Linux kernel development, as the existing version control systems were not efficient enough for such a large and complex project.

Here’s a glimpse of Git’s history:

• Early Days (2002-2005): Linux kernel development relied on a proprietary DVCS called BitKeeper. When its free-of-charge use was revoked, Torvalds decided to create his own version control system, with the goal of being faster, simpler, and more robust.
• Birth of Git (April 2005): Torvalds began work on Git and within a remarkably short period, had a functional system ready to manage the Linux kernel.
• Community Takes Over (July 2005): Junio Hamano took over the maintenance of Git, guiding its development and shaping it into the mature system it is today.
• Widespread Adoption: Git’s speed, flexibility, and powerful features quickly gained popularity among developers. It became the preferred choice for open-source projects and eventually spread to commercial software development.

Today, Git is the most widely used version control system worldwide, powering the development of countless software projects, from small personal projects to massive corporate endeavors.

Installation of Git

• Signup to github.com
• Install git with gitbash in windows
• or via package manager in linux
  • for ubuntu apt install git
  • for rhel based distros yum install git
  • for arch based distros pacman -S git

Initializing empty repository as git

• Create empty folder in local machine
• navigate to it and run git init
• add some files and run git add .
• commit changes `git commit -m “git initialized and new files added”
• Create repository in github and use its link to below step
• Add remote repo git remote add origin [email protected]:<username>/<repo-name>.git
• update the remote repo with push git push origin main

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Basic Git Commands

Adding Files to Staging Area

git add . 

This command will staged all files and modifications done in current and subdirectories but wont wont stage deletions.

git add -A 

This command will stage all types of changes across your entire working directory including newfiles, modifications and deletions

This command will commit changes into git

git commit -m "new commit"

Creates a commit with the specified message. This is the most common way to commit changes.

git commit -A "your commit message"

Automatically stages all tracked files that have been modified and deleted, then creates a commit. It combines git add -A and git commit -m into a single command.

Does not stage any new files. If you have new files you want to include in the commit, you still need to stage them separately using git add.

Syncing latest commit to remote repo

git push origin main

Uploads your local changes to the remote repository. After pushing, other developers can access your changes by pulling from the remote repository.

Pulling latest changes from remote to local

git pull origin main

Downloads changes from the remote repository to your local repository. Used to stay up-to-date with the latest changes made by other develpers.*