Git & GitHub Documentation
Published: 2022-03-09 15:25:19

Lesson 1. Introduction to git and GitHub

    git?
        git is a version control software
        It keep track of code changes
        It helps to collaborate in a project
        It is installed and maintained locally
        It provides Command Line Interface (CLI)
        Released in April 7, 2005
        Developed by Linus Torvalds & Junio C Hamano
    github?
        GitHub is a hosting service where we can keep our git    repositiory/folders
        It is maintained on cloud/web
        It provides Graphical User Interface (GUI)
        Founded in 2008


Lesson 2. How to set git environment and configuration

    Download and install git on your pc: https://git-scm.com/
    check git version: open terminal or cmd then use the command git --version to find out whether git is installed or not. if git is installed it will return a version number of git.


git configuration

    check all configuartion options: git config
    set global user name and user email for all repository/git folders (if you want to set different username and email for different git repository then remove --global)
        set global user name: git config --global user.name "anisul-islam"
        set global user email: git config --global user.email "anisul2010s@yahoo.co.uk"
    list all git configuration:
        list all the configuration: git config --list
        list user name: git config user.name
        list user email: git config user.email
    change global username & email
        change global user name: git config --global user.name "PUT_NEW_USER_NAME_HERE"
        change global user email: git config --global user.email "PUT_NEW_USER_EMAIL_HERE"


Lesson 3. creating git repo and adding new files

    creating a git folder

    ls -a : list all files inside of a directory

   

```
 `mkdir DIRECTORY_NAME_HERE
    cd DIRECTORY_NAME_HERE
    git init

    Example:
    mkdir notes
    cd notes
    git init
    ls -a
```
`
    adding new files in git folder

    git status : displays the state of the working directory and staging area

    

```
ls -a
    touch fileName.extension
    open fileName.extension
    git status

    Example:
    touch day1.txt
    open day1.txt
    write something inside the file
```

    Git is aware of the file but not added to our git repo

    Files in git repo can have 2 states – tracked (git knows and added to git repo), untracked (file in the working directory, but not added to the local repository)

    To make the file trackable stagging or adding is required


Lesson 4. how to add files in staging area & remove files

    adding files to stagging area:

    git add fileName add a file in staging area / index
    git add . add all files of directory to stagging area not subdirectory
    git add -A add all files of directory and subdirectory to stagging area
    

```
git rm --cached fileName unstage a file from staging area
    git diff - checking the differences of a staged file
    git restore fileName - restore the file

```

Lesson 5. practice-1

Lesson 6. commit & uncommit

    git commit -m "message" move the file to local repository from stagging area
    git log check the commit history
    git reset --soft HEAD^ uncommit the commit in HEAD and move to staging area
    git reset HEAD^ uncommit the commit in HEAD and move to unstaging / working area
    git reset --hard HEAD^ uncommit the commit in HEAD and delete the commit completely with all the changes


Lesson 7. git HEAD and undo theory

  

```
  git log --oneline
    git show
    git show HEAD^
    git show commit-id
    git checkout commit-id
    git checkout master
```


Lesson 8. git HEAD and undo practical

Lesson 9. git revert

Lesson 10. git ignore

    create a .gitignore file and add the things you do not want to add in the stagging area
    Inside .gitignore we can keep secret files, hidden files, temporary files, log files
    secret.txt secret.txt will be ignored
    *.txt ignore all files with .txt extension
    !main.txt ignore all files with .txt extension without .main.txt
    test?.txt ignore all files like test1.txt test2.txt
    temp/ all the files in temp folders will be ignored


Lesson 11. how to create github repository and commits

 

```
   sign in to your github account
    create a git repo
```


Lesson 12. README.md

    Everything you need to know about README.md is discussed in the video.
    6 heading levels: number of hashes define heading levels. check the following examples:
        # heading 1 level text is here
        ## heading 2 level text is here
    bold syntax: __text goes here__
    italic syntax: _text goes here_
    italic syntax: _text goes here_
    strikethrouh syntax: ~this is~~
    single line code syntax: `` place code inside backticks
    multiple line code syntax: ``` place code inside three open and closing backticks
    multiple line code syntax: ```html for specific lanaguage use language name when starting; not closing
    for more please check the video by clicking the link given above


Lesson 13. Connecting local repo to remote repo

    check remote connection: git remote or git remote -v
    git remote add name <REMOTE_URL> example: git remote add origin http://...


Lesson 14. push and pull

  

```
  push a branch git push -u origin branch_name
    push all branches git push --all
    pull from a repo: git pull which is equivalent to git fetch + git merge
```


Lesson 15. branching and merging

    Branch is a new and separate branch of master/main repository
    create a branch git branch branch_name
    List branches git branch
    List all remote branches git branch -r
    List all local & remote branches git branch -a
    move to a branch git checkout branch_name
    create and move to a branch git checkout -b branch_name
    delete a branch: git branch -d branch_name
    merge branches:

     

```
 git checkout branchName
      git merge branchName

    git log --oneline --all --graph
```


Lesson 18. branching and merging locally

Lesson 19. git and GitHub practice - 2

Lesson 20. GitHub Issues

Lesson 21. 2-way and 3-way merges

    Reeference:
       

```
 https://www.tutorialspoint.com/what-is-a-fast-forward-merge-in-git
        https://www.tutorialspoint.com/what-is-3-way-merge-or-merge-commit-in-git
        https://medium.com/@koteswar.meesala/git-fast-forward-merge-vs-three-way-merge-8591434dd350
```


Lesson 22. Merge Conflicts

    

```
https://www.tutorialspoint.com/what-is-merge-conflict-in-git-how-to-handle-merge-conflicts
```

```

```