Git and GitHub Tutorial

GitHub is a Web-based Git repository hosting service, which offers all of the distributed revision control and source code management (SCM) functionality of Git as well as adding its own features. 

Unlike Git, which is strictly a command-line tool, GitHub provides a Web-based graphical interface and desktop as well as mobile integration. It also provides access control and several collaboration features such as bug tracking, feature requests, task management, and wikis for every project.

Source : Github Wiki

Terms and Definitions.

SNAPSHOT/COMMIT

It commits a snapshot that you can refer back to.

CACHE(INDEX / STAGING AREA)

Place where all the active files are placed , monitored before committing

Git Repository 

Located in local folder staging , any folder/dir when initialized becomes git repository.

Create pair of Public / Private Keys

ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

To check our public key works 

After Adding public key to github SSH Keys

ssh -T git@github.com

Configure Git

git config --global user.name "Name"

git config --global user.email "Email@domain"

To check the config

git config --list 

Now  let's create a directory

mkdir gitproject  // master branch for our project 

cd gitproject

vim readme.txt

vim test.txt

git status  // tells what branch you are in , what files have changed, what files are tracked , hints on what to do next.

Now let's add the files to staging are 

git add .  // shortcut to add all the files in present directory

git rm --cached <filename> // to remove file from staging area

git commit -m "message for commit"

git log // check the commit log

git diff  // check the difference of updated file before adding to the staged area

git diff --cached //check the diff after adding to staged area

git log --oneline //only commit messages

git commit -a -m "message"  // adding files to staged area and committing in one line

git status -s  // short status 

Create a new repository on GitHub and copy the link
Eg(https://github.com/viprai91/SampleTutorial.git)

To push an existing repository to github 

git remote add origin "name of remote repo"

(Eg : git remote add origin https://github.com/viprai91/SampleTutorial.git)

git push origin master 

// origin is the name we gave in above step , master is the parent directory , also once added to remote , use the same command to push the changes

Branching - Allows to create a separate working copy of code

Merging - Allows to merge branches together

Cloning - Other developers can get copy of code.

Branching - 

git branch    // tells all the branches available for the repository

To create a new Branch

git checkout -b "branch_name"  // creates branch and sets new branch as working branch

or

git branch "name"  // creates branch with the name

eg: git branch r2_index

to change the branch (Note the current branch will have * before the name)

git checkout r2_index

 // Switched to branch 'r2_index'

// to clone the same repo for other dev on diff computer use clone

git clone sshlink

git clone https://github.com/viprai91/SampleTutorial.git

Merge

// to merge changes from branches to master 

git merge master // when we are in r2_index and need to merge to master

Pull

Pull syncs local repository with remote repo

git pull github master

Note: Always pull before push, so that we have the latest version of the code which might have been edited by someone else.