# Github Notes

The purpose of Git is to manage a project, or a set of files, as they change over time. Git stores this information in a data structure called a repository. A git repository contains, among other things, the following: A set of commit objects.

Store revisions in a project history in just one directory
Revind to any any revision in the project
Work on new features without messing up the main codebase
Easily collaborate with other programmers

Github on the other hand is where you can host your files. Share your code with other developers.

# How does Github works?

Every project in Github is called as Repo (short for repository). It can be stored any where such as local or remote. They will be tracked by Git. Now, there is another concept called as Commits. Think of this as save files in your games. You can return to any save files whenever you want.

There are 3 stages to a repo.

Modified: Changes that are made to the files. These are not commited
Staging: Any changes files to the staging that you want to commit
Commited: Any files in the staging area are added to the commit when we make one

# Installation

Install Git from this link: https://git-scm.com/
Any text editor to edit your code files

You will have to let Git know as to who you are. You can do the same by following the below set of coding instructions.

git config --global user.name shahidshaikhs

git config --global user.email shahid.sk27595@gmail.com

If you wish to check as to which user is currently loggin in, use the below command:

git config user.name

# Creating a repository

git init

# Staging Files

To check as to which files are changed and which files are in the staging area

git status

To add files to the staging area:

git add <name of the file>

//OR (to add all the files to staging)

git add .

To remove files from the staging area:
```
git rm --cached <name of the file>
```

# Commiting changes

Think of this as save files in your games.

git commit -m "fixes a bug in header"

// Make sure commit messages are very descriptive.

When you fire this command, you will receive an ID of that commit on the master branch.

Now, to see the commits that you have made, you can use the below command:

git log

git log --oneline

To see the changes in brief

# Undoing things

There are 3 type of things which you can do there:

Checkout commit (very safe) You can only checkout what code was like at a particular commit.

git checkout <id of the commit>

Revert commit (moderate) You can undo the commit here. This will not actually remove the commit, but add another commit which says 'Revert 'something something'' and remove the code which was present in that particular commit.

git revert <commit id>

Reset commit (unsafe) Permanently go back in time to back to a commit. This will remove all the recent commits till the commit ID you specify. Remember when you do this, the changes that you made to the file will be unstaged basically and you can commit them again if required.

git reset <commit id>

git reset <commid id> --hard

This command will not keep any changes in the unstaged area. It will remove every change made after the mentioned commit.

# Branches

In the above steps we were just working on the master branch. We can create a new branch, which will be like an isolated branch to test new code and later merge this branch with the master branch.

Create a new branch
```
git branch branchName
```
See all branches
```
git branch -a
```

Switch branch

git checkout branchName

OR

git checkout -b branchName (This will create a new branch and also checkout the same)

Delete branch First go to the master branch, then delete the new branch
```
git branch -d branchName
```

# Merge Branches

First we got to be on the branch that we want to merge into. Lets say you want to merge 'feature b' branch with Master, then you will have to first be on the master branch.

git merge <branch name>

# Pushing code to Github

Create a repo at Github
You will get a link, copy the same
git push https://github.com/shahidshaikhs/learning-github.git master
Setup Alias git remote add origin https://github.com/shahidshaikhs/learning-github.git

# Cloning

Use the below code to clone a repo on your local machine

git clone <repo link>

# Collaborating on Github

Clone project on your local machine
Create a new branch and push changes to the same branch
Create a pull request with this new branch

Also, always make sure that you pull from master before creating a new branch.

# Forking

A fork is a copy of a repository. Forking a repository allows you to freely experiment with changes without affecting the original project. Most commonly, forks are used to either propose changes to someone else's project or to use someone else's project as a starting point for your own idea.

Once you fork the project and make changes to the same you can then contriubte to the origin repository by following below steps:

Go to the original repo and click on 'New Pull Request'.
The authoer of the original repo will merge the changes if they like your changes.

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