A Comprehensive Guide: Mastering Git from Basics to Techniques

Introduction to Git

Git, the most widely used version control system, has revolutionized the way developers collaborate on projects and track changes to their code. In this comprehensive guide, we will explore Git from its basics to advanced techniques, empowering you to utilize Git effectively in your projects.

What is Git?

At its core, Git is a distributed version control system that allows multiple developers to work on the same project simultaneously. It tracks changes to files, recording every modification, addition, or deletion made to the codebase.

Why Git is essential for version control?

Version control is crucial in software development as it allows for seamless collaboration, easier bug tracking, and efficient code management. Git provides a robust set of features that enable developers to work on projects efficiently and revert changes when necessary.

Installing Git on various operating systems

To get started with Git, you need to install it on your computer. Git is compatible with Windows, macOS, and Linux. Visit the official Git website and download the installer for your operating system. Follow the installation instructions to set up Git on your machine.

Getting Started with Git

Before diving into the intricacies of Git, let’s start with the basic setup and understand its fundamental concepts.

Setting up a Git Repository

To begin using Git, you need to set up a repository, which is like a centralized hub for your project.

Initializing a local repository

To create a local repository, open the terminal and navigate to the directory of your project. Then, type the following command:

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git init

This command will initialize an empty Git repository in your project folder. The .git subdirectory will be created, which will store all of the metadata for your repository.

Cloning an existing repository

If you’re working on a project that already exists in a remote repository, you can bring a copy of it to your local machine using the command git clone <repository-url>. This command creates a local replica of the entire repository on your computer.

For instance, suppose you want to clone a repository named my-project hosted on GitHub. You would execute the following command:

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git clone https://github.com/username/my-project.git

This command creates a local copy of the repository in a directory named my-project within your current directory. Once the repository is cloned, you can embark on your work by modifying files and adding them to staging.

Setting up a remote repository

To collaborate effectively with other developers, establish a remote repository on services like GitLab or GitHub. These remote repositories act as a centralized hub where team members can share and synchronize their code changes. To link your local repository to a remote one, use the git remote add command, specifying the remote name and URL. For instance, to connect to a repository named upstream hosted on GitHub, you’d execute:

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git remote add upstream https://github.com/username/repo.git

This command adds a remote reference named upstream to your local repository, enabling you to push changes to the remote repository and pull updates from it.

Git Basics

Before we delve deeper into Git’s features, let’s understand the basic workflow and configuration options.

Understanding Git’s basic workflow

Git’s core workflow revolves around three essential steps: adding, committing, and pushing. Let’s delve into each phase:

Adding:

The first step involves preparing the files you want to track with Git. Use the git add <file> command to stage the desired files for inclusion in the next commit. For instance, to add a file named index.html, you would execute:

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git add index.html

This command moves the file from your working tree to the staging area.

Committing:

After staging the files you want to track, it’s time to create a snapshot of your work. This is done using the git commit command, which records the changes made to the staged files and stores them in the local repository. The commit message should concisely describe the changes you’ve made. For example, to commit the modified index.html file, use:

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git commit -m "Updated index.html"

The -m flag specifies the commit message, which provides context for the changes.

Pushing:

Once you’ve committed your changes locally, you can share them with others by pushing them to a remote repository. This is commonly done using a hosting service like GitHub or GitLab. Use the git push command to upload your local commits to the remote repository. For instance, if your remote repository is hosted on GitHub, you would execute:

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git push origin main

This command pushes the local commits to the main branch of the remote repository.

The diagram below summarizes the Git workflow:

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Working Tree        Staging Area        Local Repository        Remote Repository
----------------------------------------------------------------------------------
(Modified Files)    (Staged Files)      (Committed Changes)    (Published Changes)

Working tree: Your current project files. Staging area: A temporary holding area for files to be committed. Local repository: Stores a history of your commits. Remote repository: Shared with others and acts as a central hub for collaboration.

Configuring Git settings

Git offers a comprehensive configuration system that empowers you to customize your workflow and personalize your development experience. Global settings, applied to all repositories, include specifying your name and email address, which are associated with your commits. Local settings, specific to individual repositories, allow you to define default branch names and create aliases for frequently used commands.

To set your global name and email address, use the git config command with the appropriate options:

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

To establish default branch names, use the following command:

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git config --global init.defaultBranch main

This sets the default branch name for newly initialized repositories to main.

Creating aliases for commonly used commands simplifies your workflow. For instance, to create an alias for git status called git st, use:

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git config --global alias.st status

With this alias in place, you can simply type git st to check the status of your repository.

Creating and managing branches

Branching is a cornerstone of Git, enabling you to work on multiple features or bug fixes concurrently without disrupting the main codebase. It’s like having multiple lanes on a highway, allowing for efficient traffic flow.

Creating a Branch:

To carve out a new branch, simply execute the command:

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git branch <branch-name>

Replace <branch-name> with the desired name for your branch. For example, to create a branch named feature_1, you would type:

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git branch feature_1

Switching Branches:

Imagine jumping from one lane to another on the highway. Similarly, Git lets you switch between branches to focus on specific tasks. Use the command:

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git checkout <branch-name>

This command directs your workspace to the specified branch. If you want to switch to the branch you just created, feature_1, use:

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git checkout feature_1

Switching and creating a branch:

In addition to creating and switching between branches, Git provides a convenient shortcut for both actions using the git checkout -b command. This command simultaneously creates a new branch and switches to it, eliminating the need for separate git branch and git checkout commands.

To create a new branch named feature_2 and switch to it immediately, use:

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git checkout -b feature_2

This command effectively combines the steps of creating and switching branches, streamlining your workflow and saving time.

Working with Commits

Commits are at the heart of Git’s version control system. They represent a snapshot of your codebase at a specific point in time.

Creating and committing changes to the repository

To create a new commit in Git, you’ll need to follow two steps: staging the changes and committing them. Staging involves preparing the files you want to include in the commit, while committing actually saves those changes to the Git repository.

To stage changes, use the git add command followed by the name of the file you want to stage. For example, to stage the file index.html, you would execute:

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git add index.html

Once you’ve staged the files you want to commit, you can commit them using the git commit command. The -m flag specifies a descriptive message that explains the changes you’ve made. For instance, to commit the changes to index.html, you would use:

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git commit -m "Updated index.html"

The commit message should be concise and informative, summarizing the changes made in the commit. It should be clear enough for you or others to understand what was changed and why.

Viewing commit history and differences

Journey through the evolutionary path of your codebase with git log, a versatile tool that meticulously documents the repository’s commit history. Explore the author, date, and concise summaries of modifications introduced across each commit. To delve into specific details, employ the git log command.

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git log

Visualize the branching structure with git log --graph, transforming the commit history into a captivating graph. Condense the commit timeline into a single line with git log --pretty=oneline.

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# tree structure
git log --graph
# condensing messages
git log --pretty=oneline
# combining for better readibility
git log --pretty=oneline --graph
# adding all the remote branches to the previous command
git log --pretty=oneline --graph --all

Navigate commits by author, date, or specific keywords with options like git log --author="johndoe" and git log --grep="bug". Explore the commit history of a specific branch or all branches except one.

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git log --author="johndoe"
git log --grep="bug"
git log <branch_name>
git log --not <branch_name>

Mastering git log empowers you to comprehend your repository’s evolution, enabling informed decision-making and efficient collaboration.

Uncover Codebase Evolution with git diff

Your key to understanding changes in your codebase is git diff. This powerful tool meticulously compares files between versions, highlighting modifications with clarity.

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git diff

Side-by-Side Comparison:

Visualize the file’s journey with git diff <file_name>. Added and removed lines are displayed side-by-side for easy understanding.

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git diff <file_name>

Enhanced Visualization with Color:

Deepen your comprehension with git diff --color-words <file_name>. This command showcases added and removed words in distinct colors, offering a visually striking representation of the changes.

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git diff --color-words <file_name>

Comparing Branches:

Uncover specific branch modifications with git diff HEAD <branch_name>. This command reveals the differences introduced in a chosen branch compared to your current branch.

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git diff HEAD <branch_name>

Mastering git diff equips you to comprehensively analyze and grasp codebase evolution.

Addressing Commit Errors and Making Changes Before Pushing

To rectify any mistakes in your recent commit or incorporate further changes before pushing them, Git offers methods to undo or modify existing commits.

Reverting the Most Recent Commit:

To reverse the most recent commit, employ the following command:

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git reset HEAD~1

This command will undo the most recent commit, placing your codebase back to the state it was in before you made the commit.

Amending the Previous Commit:

To enhance the previous commit with additional modifications, utilize the following command:

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git commit --amend

This command will open your default text editor, allowing you to modify the commit message and add any additional changes you want to make. Once you have made your changes, save the file and exit the editor. Git will then recommit the changes, effectively updating the previous commit.

Git Force Push: A Powerful Tool for Overriding Remote History

Git force push is a potent tool that allows you to overwrite remote branch history, effectively overriding changes made by others. This feature can be useful in specific situations, but it’s crucial to exercise extreme caution when using it. Force pushing disrupt collaboration and lead to conflicts, so it should only be employed when absolutely necessary.

Here’s an example of how to use git force push to correct a mistake in your local commits that have already been pushed to the remote branch:

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git add <file_name>
git commit -m "Corrected mistake from previous commit"
git push --force

This command will overwrite the remote branch history with your updated commits. However, it’s important to note that this action will erase any changes made to the remote branch by other collaborators since your last push.

Another scenario where force push might be appropriate is when merging a feature branch into a main branch and forcing it to overwrite the remote main branch with your changes:

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git checkout main
git merge feature-branch
git push --force

This command will overwrite the remote main branch with the changes from your feature branch, ensuring that your feature is integrated.

Regardless of the situation, it’s critical to use force push with extreme caution. Only resort to it when you’re absolutely certain it’s the only way to resolve a serious issue. Always communicate with your team beforehand to avoid disruptions and maintain a collaborative environment.

Collaboration and Remote Repositories

Git’s true power shines when collaborating with others on a project. Let’s explore different techniques to collaborate efficiently and resolve conflicts.

Collaborative Development with Git

Working with remote repositories and understanding collaborative workflows is vital for contributing to open-source projects or collaborating with teammates.

Collaborating with Remote Repositories

Remote repositories serve as the central hub for collaboration on a project, enabling developers to work together seamlessly. They act as a centralized storage for the project’s codebase, ensuring that all contributors have access to the latest changes.

Fetching Updates from Remote Repositories:

To incorporate the latest changes from other developers into your local repository, use the git pull command. This command fetches the latest changes from the remote repository and merges them into your local branch, keeping your codebase up-to-date.

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git pull <remote-repository-name> <remote-branch-name>

Here’s an example of fetching updates from the main branch of a remote repository named origin and merging them into your local main branch:

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git pull origin main

git pull use git fetch under the hood in order to update the remote tracking branche.

Pushing Changes to Remote Repositories

To share your local changes with the remote repository, use the git push command. This command synchronizes your local repository with the remote repository, sending your commits to the central location.

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git push <remote-repository-name> <branch-name>

Here’s an example of pushing changes to the main branch of a remote repository named origin:

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git push origin main

Ensuring a Consistent Codebase

To maintain a consistent and up-to-date codebase, it is recommended to follow the “pull-modify-push” workflow. This involves first pulling the latest changes from the remote repository using git pull. This ensures that your local repository is synchronized with the latest changes made by others. Once you have pulled the latest changes, you can proceed to modify your code and make your own contributions and commit them locally using git addand git commit commands. Finally, when you are ready to share your changes with others, you can push your commits to the remote repository using git push.

This workflow helps to prevent conflicts and ensure that everyone is working with the same codebase. By pulling the latest changes before making your own, you can be sure that your contributions are compatible with the work of others.

Get Inside Your Codebase with git status

Before diving into changes, understanding your project’s current state is crucial. That’s where git status comes in. This handy command acts like a snapshot, revealing:

• Unstaged changes: Modifications made to tracked files not yet marked for inclusion in your next commit.
• Staged changes: Files you’ve explicitly chosen to be part of your next commit.
• Untracked files: New files created within your project that Git hasn’t been introduced to yet.

By using git status regularly, you maintain a clear picture of your codebase, ensuring smooth sailing during version control operations.

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git status

Branching and Merging

In software development, branching allows developers to work on separate versions of the codebase without affecting each other’s work. Merging combines these individual branches back into a unified codebase. Together, branching and merging enable parallel development, collaboration, and a consistent codebase. These techniques are essential for agile development and ensuring project success.

Creating and merging branches

Once you’ve completed your work on a branch, you can integrate its changes into the main codebase. This process is called merging. Execute the command:

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git merge <branch-name>

Replace <branch-name> with the name of the branch you want to merge into the current working branch. Merging combines the changes made in the <branch-name> with the current branch, creating a single, unified history.

Managing Conflicts in Collaborative Development

In collaborative environments, simultaneous modifications to the same file can occur. Git meticulously detects these conflicts and marks the affected file with distinct markers. To resolve the conflict, you’ll need to manually review the changes and selectively retain the desired modifications.

Once the conflict is resolved, you can proceed to stage and commit the changes as usual. Git will incorporate the resolved conflict into a single commit, maintaining the codebase’s integrity.

Consider an instance where you and another developer are working on the same index.html file. After making changes, you run git status to assess the file’s status. Git flags index.html as conflicting due to concurrent modifications by the other developer.

Resolving the Conflict

To address this conflict, open index.html in your text editor. The file will display special markers indicating the conflicting changes. Carefully examine the modifications and select the ones you want to keep.

Code Block:

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<<<<<<< HEAD
Your modified line 1
=======
Other developer's modified line 1
>>>>>>> other-branch

Save your changes and exit the editor. Git will recognize the conflict resolution and allow you to stage and commit the modifications. Your commit will encompass the resolved conflict, ensuring a unified codebase.

Working with remote branches

Remote branches serve as pointers to branches in the remote repository, allowing you to synchronize your local work with the central codebase. To create and switch to a new local branch tracking a remote branch, use the following command:

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git checkout -b <local-branch-name> origin/<remote-branch-name>

This command will create a new local branch named <local-branch-name> and set it to track the remote branch <remote-branch-name>. If the <remote-branch-name>does not exists in the origin, is possible to omit it from the command:

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git checkout -b <local-branch-name>

When you push your changes to a remote branch for the first time, you need to tell Git to associate that local branch with the remote branch. Use the git push -u command to establish this connection:

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git push -u origin <local-branch-name>

This command will push your local branch to the remote repository and set it as the upstream branch for future pushes.

Git Tools for Collaboration

Git provides various tools and platforms to enhance collaboration and automate workflows.

Using Git hooks for automation

Git hooks allow you to automate tasks before or after specific Git actions. You can use pre-commit hooks for format checking, running tests, or other custom actions. Post-commit hooks can trigger notifications or update external systems.

Leveraging GitLab or GitHub for collaboration

GitLab and GitHub offer comprehensive collaboration features for teams. They provide features like pull requests, code reviews, issue tracking, and continuous integration. Familiarize yourself with these platforms to streamline your collaborative workflows.

Managing Git submodules for complex projects

Submodules enable you to include external repositories within your own repository. This is useful when working with complex projects that rely on external libraries or modules. Git submodules allow separate version control and easier integration of external code.

Advanced Git Techniques

As you become more proficient with Git, exploring advanced techniques can enhance your productivity and make your workflows more efficient.

Advanced Branching Strategies

Advanced branching strategies allow for smooth parallel development, long-term maintenance, and release management.

Feature branching and release branching

Feature branching involves creating separate branches for each new feature or enhancement. Developers work on these branches independently before merging them back into the main branch. Release branching, on the other hand, involves creating a branch for a specific release version, allowing bug fixes and subsequent releases without affecting ongoing development.

Gitflow workflow

Gitflow is a popular branching model that provides a specific structure for long-term projects. It defines branches for features, releases, hotfixes, and more. This workflow ensures a clean separation of different development stages and facilitates effective collaboration.

Rebasing vs. Merging: Choosing the Right Strategy for Branch Integration

In the world of version control, rebasing and merging represent two prevalent techniques for combining branches. While both approaches serve the purpose of integrating changes from one branch into another, they differ in their impact on the branch history.

Rebasing: Rewriting History for Seamless Integration

Rebasing involves modifying the history of a branch to ensure it seamlessly merges into another branch. This technique effectively rewrites the branch’s commit timeline, creating a linear sequence of commits. Rebasing is particularly beneficial when integrating feature branches into the main development branch, as it eliminates the need for merge commits.

Merging: Preserving Branch Histories for Tracing Development

In contrast, merging retains the separate histories of individual branches, providing a more granular view of the development process. This approach is advantageous in scenarios where you need to trace the evolution of features or identify specific changes made at different points in time. However, merging can introduce merge commits, which may make it harder to follow the linear flow of commits.

Specialized Rebasing Techniques: Squash and Interactive Rebasing

Rebasing can sometimes raise concerns about rewriting history. To address these concerns, Git offers two specialized rebasing techniques: squash and interactive rebasing.

• Squash rebasing combines multiple commits into a single, more concise commit, streamlining the branch history and minimizing the impact of rebasing on the overall project history.

• Interactive rebasing provides a more granular control over the rebasing process, allowing you to review and modify individual commits before applying them to the target branch.

Choosing the Right Strategy: Balancing History Management and Integration

The choice between rebasing and merging depends on the specific context and desired outcome. Rebasing is ideal for maintaining a clean, linear history, particularly when integrating feature branches into the main branch. However, it’s crucial to exercise caution when rebasing in a collaborative environment, as rewriting history may disrupt the work of other developers.

Merging, on the other hand, preserves branch histories, facilitating better understanding of the development process and enabling historical analysis. However, merging may introduce merge commits, which may make the commit timeline less straightforward.

Squash and interactive rebasing offer further refinements to the rebasing process, allowing developers to manage history more effectively while maintaining control over the integration process.

Git Stash and Reflog

Git stash and reflog are handy tools that help manage temporary changes and recover lost commits.

Using Git stash for temporary changes

Git stash serves as a handy tool for temporarily storing your uncommitted changes, allowing you to switch branches or work on different tasks without losing your progress. This technique involves saving your current state into a stash and reverting your working directory to the last committed state.

Example of Using Git Stash:

Consider the scenario where you’re working on a feature branch and need to switch to the main branch to fix a critical bug. Instead of committing your unfinished changes, you can use Git stash to temporarily store them and then switch branches. Here’s how to do it:

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git stash
git checkout main

This will stash your uncommitted changes and switch you to the main branch. You can then fix the bug and commit the changes to the main branch. Once you’re done, you can switch back to your feature branch and apply the stashed changes using the following command:

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git checkout feature-branch
git stash pop

This will restore your uncommitted changes from the stash and switch you back to your feature branch. Your work will be seamlessly resumed, and you can continue developing your feature without losing any progress.

Recovering lost commits with Git reflog

Git reflog keeps track of the changes to the branch references. If you accidentally delete a branch or lose commits, you can use git reflog to identify the commit hash and recover it.

Best practices for using stash and reflog

When using stash, it’s essential to provide descriptive stash messages to easily identify the purpose of each stash. When utilizing reflog, it’s beneficial to regularly create backups of your repository to avoid permanent loss of data.

Git Workflows for Large Teams

In large teams, implementing effective Git workflows ensures smooth collaboration, code quality, and project management.

Managing conflicts in large teams

As the number of developers increases, the probability of conflicts also rises. Encouraging frequent and clear communication, utilizing branches for features, and emphasizing code review practices can help manage conflicts efficiently.

Implementing code review processes with Git

Code reviews play a crucial role in maintaining code quality. Establishing guidelines and a structured code review process ensures consistency and catches potential issues before code is merged into the main branch. Use tools like pull requests and code review platforms to streamline this process.

Strategies for efficient remote branching and merging

In large teams spread across different locations, efficient remote branching and merging are crucial for seamless collaboration. Define clear naming conventions for branches, maintain a clean branch structure, and use tools like continuous integration and automated testing to ensure code integrity.

Summary and FAQs

Throughout this comprehensive guide, we have covered key Git concepts and techniques that range from the basics to advanced usage. By following these practices, you will gain the knowledge and skills required to use Git effectively in your projects. Whether you’re a beginner or an experienced developer, this guide empowers you to harness the full potential of Git for version control, collaboration, and advanced techniques.

Frequently Asked Questions (FAQs) about Git usage and troubleshooting

1. How to undo a commit in Git?
   • To undo the last commit, use git reset HEAD~1. This command removes the last commit but keeps the changes in your working directory.
2. Can Git handle large binary files?
   • Git is primarily designed for managing text files. While it can handle binary files, storing large binary files in Git repositories is not recommended due to the impact on repository size and performance. Consider using LFS (Large File Storage) or other external solutions for managing large binary files.
3. How to recover a deleted branch in Git?
   • If a branch is deleted accidentally, you can use git reflog to find the commit hash of the deleted branch. Once you have the commit hash, you can recreate the branch using git branch <branch-name> <commit-hash>.

By following this comprehensive guide, you will gain the knowledge and skills required to effectively use Git for version control, collaboration, and advanced techniques. Whether you’re a beginner or an experienced developer, this guide will empower you to utilize Git efficiently in your projects.

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