This is an introduction to version control systems and git

1. Introduction to Git
Siddhant Bhardwaj

2. What is Git ?
● Git is a version control system.
● Git helps you keep track of code changes.
● Git is used to collaborate on code.

3. What Does Git Do ?
● Manage projects with Repositories
● Clone a project to work on a local copy
● Control and track changes with
● Staging and Committing Branch and Merge to allow for work on
different parts and versions of a project
● Pull the latest version of the project to a local copy Push local
updates to the main project

4. How Does Git Work ?
Initialize Git on a folder, making it a Repository
Git now creates a hidden folder to keep track of changes in that folder
When a file is changed, added or deleted, it is considered modified
You select the modified files you want to Stage
The Staged files are Committed, which prompts Git to store a permanent
snapshot of the files
Git allows you to see the full history of every commit.
You can revert back to any previous commit. Git does not store a separate
copy of every file in every commit, but keeps track of changes made in each
commit!

5. Creating a Git Repo
● In order to create a git repository, we need to use the command - git
init in the folder where we desire to create a git repo.

6. Git Staging
Now our git repository has been created, but it does not have any files
yet.
When we create a new file in the repository, ls will list the files in the
directory.
Then we check the Git status and see if it is a part of our repo.
We can check by using the command git status.

7. Git Staging
Now Git is aware of the file, but has not added it to our repository!
Files in your Git repository folder can be in one of 2 states:
● Tracked - files that Git knows about and are added to the repository
.
● Untracked - files that are in your working directory, but not added
to the repository

8. Git Commit
Since we have finished our work, we are ready move from stage to
commit for our repo.
Adding commits keep track of our progress and changes as we work.
When we commit, we should always include a message.
git commit -m "First release of Hello World!"
The commit command performs a commit, and the -m "message" adds a
message.

9. Git Help
If you are having trouble remembering commands or options for
commands, you can use Git help.
There are a couple of different ways you can use the help command
in command line:
git command -help - See all the available options for the specific
command
git help --all - See all possible commands

10. Git Branch
In Git, a branch is a new/separate version of the main repository.
Branches allow you to work on different parts of a project without impacting
the main branch.
When the work is complete, a branch can be merged with the main project.
git branch new-branch is used to create a new branch.
git checkout new-branch can be used to checkout a branch.
git checkout -b new-branch can be used to create and checkout a new branch.

11. Git Merge Branch
First, we need to change to the main branch:
git checkout main.
Now we merge the current branch (main) with new-branch:
git merge new-branch.

12. Gitignore
When sharing your code with others, there are often files or parts of your
project, you do not want to share - personal files, log files etc.
Git can specify which files or parts of your project should be ignored by
Git using a .gitignore file.
Git will not track files and folders specified in .gitignore. However, the
.gitignore file itself IS tracked by Git.

13. Git Revert
revert is the command we use when we want to take a previous commit
and add it as a new commit, keeping the log intact.
git revert <commit hash>
In order to obtain the commit hash of the commit that we want to revert
to, we can use the following command - git log --oneline

14. Git Reset
reset is the command we use when we want to move the repository back
to a previous commit, discarding any changes made after that commit.
It brings the repository back to an earlier state in the commits without
making a new commit.
Similar to git revert, we get the hashcode of the git commit we want to
reset to -
git reset <git hash>