Git Basic Commands
++++++++++++++++++++++++++++++++++++++
git init
git config user.name "Raj_Gupta"
git config user.email "rajgupta.ckt22@gmail.com"
git add . (or) git add -A
git status
git commit -a -m "First times the addition of all files"
git log --oneline
git help --all
git rm --cached -r . =>To unstaged all files
Git
===============>
Git is a version control system that helps you keep track of code changes.
Git is used to collaborate on code.
It was created by Linus Torvalds in 2005, and has been maintained by Junio Hamano since then.
It is used for:
=>Tracking code changes
=>Tracking who made changes
=>Coding collaboration
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
Main Points Of Git
=======================>
1) Repositories
2) Clone=> To pull a remote repository to your local computer is called cloning.
use cmd to clone a remote repo=> git clone SpecifiedURL(which u will get from git hub).
3) Staging and Committing
4) Branch and Merge
5) Pull
6) Push
Working with Git
===================>
Initialize Git on a folder, making it a Repository=> git init
Git now creates a hidden folder to keep track of changes in that folder named .git
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!
Why Git?
==============>
Over 70% of developers use Git!
Developers can work together from anywhere in the world.
Developers can see the full history of the project.
Developers can revert to earlier versions of a project
Git Install
You can download Git for free from the following website: https://www.git-scm.com/
After downloading the git you can check if git is installed or not.
git --version
How to work with git in an application (working dir=>staging environment=>commit)
=========================================>
1) git init =>To Initialize a hidden git repository
2) Configure Git =>To tell the Git who we are. This is important as each Git commit uses this information:
git config --global user.name "w3schools-test"
git config --global user.email "test@w3schools.com"
Note:Use global to set the username and e-mail for every repository on your computer.
3) git add . => To add all files to a staging environment where git knows about your app files.
Note: Files in your Git repository folder can be in one of 2 states:
Tracked
Untracked - files that are in your working directory, but not added to the repository
4) git status => To views the added,modified and deleted files
5)Git Staging Environment=>Staged files are files that are ready to be committed to the repository you are working on.
As you are working, you may be adding, editing and removing files.
But whenever you hit a milestone or finish a part of the work, you should add the files to a Staging Environment.
we add all our files to stagging environment using git add . command.
6)Git Commit
Adding commits keep track of our progress and changes as we work.
Git considers each commit change point or "save point".
It is a point in the project you can go back to if you find a bug, or want to make a change.
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.
7) Working with Git Branches
===========================>
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.
You can even switch between branches and work on different projects without them interfering with each other.
Commands related branch
===========================>
a) git branch branch_name =>Creating new branch
b) git checkout branch_name =>To move from current branch to another branch named branch_name
c) git branch =>To check the current branch
d) git checkout -b branchName=>Using the -b option on checkout will create a new branch, and move to it, if it does not exist
e) git merge branch_name=> To add the code of branch_name branch to the current branch.
f) git branch -a====>we can use the -a option to see all local and remote branches.
g) git branch -d branch_name ====>To delete a branch named branch_name
8) Git Ignore and .gitignore
===============================>
When sharing your code with others, there are often files/folders of your project, you do not want to share.
Example-log files, temporary files, hidden files, personal files, secret files
To acheive this functionality
==============================>
a) we create a .gitignore file in the working directory.
b) And add the files and folders which we dont't want to share with anyone else.
Writing with .gitignore files to ignore the files/folders
===========================================================>
a) Write *.log in .gitignore file to ignore any files with the .log extension.
b) To write a comment use #
c) To ignore all files in a directory named temp ==> write temp/ in .gitignore file.
d) To ignore ALL .js files====>*.js
e) TO ignore ALL files in ANY directory named node_modules==>node_modules/
Note: It is also possible to have additional .gitignore files in subdirectories. These only apply to files or folders within that directory.
9)Local and Personal Git Ignore Rules
=====================================>
It is also possible to ignore files or folders but not show it in the distributed .gitignore file.
These kinds of ignores are specified in the .git/info/exclude file. It works the same way as .gitignore but are not shown to anyone else.
10) To Push the code in remote repo in GitHub
a) Create a Repository on GitHub and copy the repo URL.
b) git remote add origin URL===>specifies that you are adding a remote repository.
Example: git remote add origin https://github.com/w3schools-test/hello-world.git
c) git push --set-upstream origin master =====>Now, you can check the gihubt repo that has been updated.
11) Git Pull from github
=========================>
a) git pull origin (or) git pull===> To pull the changes from your github repo to local repo
b) git log origin/master===>To view the history of github repo.
c) git diff origin/master===>To view the difference between local and remote repo.
d) git merge origin/master===>An another way to pull the changes from remote repo.
12) Push the local changes to the remote repo
git push remote_variable branch_name===>To push the changes from local repo to remote repo.
git push origin master -u
13) Push a new branch to GitHub
git push origin branch_name ====>To push an another Branch to GitHub
14) GitHub Flow
The GitHub flow is a workflow designed to work well with Git and GitHub.
It focuses on branching and makes it possible for teams to experiment freely,and make deployments regularly.
The GitHub flow works like this:
a)Create a new Branch
b)Make changes and add Commits
c)Open a Pull Request
d)Review
e)Deploy
f)Merge ==>After exhaustive testing, you can merge the code into the master branch.
15) GitHub Fork
A fork is a copy of a repository.
This is useful when you want to contribute to someone else's project or start your own project based on theirs.
a) Clone a Fork from GitHub==>Now we have our own fork, but only on GitHub.
b) git clone URL==>clone on our local Git
A clone is a full copy of a repository, including all logging and versions of files.
c) git push
d) create a pull request
16) git remote -v===>To view list of remote
17) git remote rename origin upstream===>To change the name of the original origin
18)Git Security SSH
=====================>
Up to this point, we have used HTTPS to connect to our remote repository.
HTTPS will usually work just fine, but you should use SSH if you work with unsecured networks.
And sometimes, a project will require that you use SSH.
What is SSH
============>
a) SSH is a secure shell network protocol that is used for network management, remote file transfer, and remote system access.
b) SSH uses a pair of SSH keys to establish an authenticated and encrypted secure network protocol.
c) It allows for secure remote communication on unsecured open networks.
d) SSH keys are used to initiate a secure "handshake". When generating a set of keys, you will generate a "public" and "private" key.
e) The "public" key is the one you share with the remote party. Think of this more as the lock.
f) The "private" key is the one you keep for yourself in a secure place. Think of this as the key to the lock.
g) SSH keys are generated through a security algorithm. It is all very complicated, but it uses prime numbers, and large random numbers to make the public and private key.
h) It is created so that the public key can be derived from the private key, but not the other way around.
Generating an SSH Key Pair
============================>
a) In the command line for Linux, Apple, and in the Git Bash for Windows, you can generate an SSH key.
b) Start by creating a new key, using your email as a label:
Example- ssh-keygen -t rsa -b 4096 -C "rajgupta.ckt22@gmail.com"
Generating public/private rsa key pair.
Enter file in which to save the key (/Users/user/.ssh/id_rsa):
Created directory '/Users/user/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
GitHub Add SSH
====================>
a) Copy the SSH Public Key
b) In the previous chapter, we created an SSH key pair.
c) To open the public key and copy it from terminal.
cat ./ssh/id_rsa.pub
d) Go to GitHub, click your profile, and select: Settings:
e) Then select "SSH and GPG keys". and click the "New SSH key" button:
f) Select a title, and paste the public SSH key into the "Key" field, and click "Add SSH Key":
Test SSH Connection to GitHub
==================================>
ssh -T git@github.com
The authenticity of host 'github.com (140.82.121.3)' can't be established.
RSA key fingerprint is SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added 'github.com,140.82.121.3' (RSA) to the list of known hosts.
Hi w3schools-test! You've successfully authenticated, but GitHub does not provide shell access.
19) Add New GitHub SSH Remote
============================>
Now we can add a new remote via SSH to our Git.
First, get the SSH address from our repository on GitHub:
Get SSH Code Then use that address to add a new origin: git remote add origin SSH_URL
Example-git remote add ssh-origin git@github.com:w3schools-test/hello-world.git
Note: You can change a remote origin from HTTPS to SSH with the command:
git remote set-url remote-name git@github.com:username/repository.git
20) 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.
1) git log --oneline ==> Find the previous commit hash to revert.
2) git revert commit_hash --no-edit ===> Revert to the previous commit and make it as a new commit.
Example
=========>
1) Let's make a new commit, where we have "accidentally" deleted a file:
git commit -m "Just a regular update, definitely no accidents here..."
2) To view the previous commit
git log --oneline
52418f7 (HEAD -> master) Just a regular update, definitely no accidents here...
9a9add8 (origin/master) Added .gitignore
3) We want to revert to the previous commit: 52418f7 (HEAD -> master) and we see that it is the latest commit.
git revert 52418f7 --no-edit
Note: adding the option --no-edit to skip the commit message editor (getting the default revert message):
4) Now let's check the commits again
git log --oneline
e56ba1f (HEAD -> master) Revert "Just a regular update, definitely no accidents here..."
52418f7 Just a regular update, definitely no accidents here...
9a9add8 (origin/master) Added .gitignore
21) Git Reset
===============>
we'll go over git reset, which brings the repository back to an earlier state in the commits without making a new commit.
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.
1) Find the previous commit:
git log --oneline
2) Move the repository back to that step:
git reset commit_hash
3)
Example
=========>
1) git log --oneline
e56ba1f (HEAD -> master) Revert "Just a regular update."
52418f7 Just a regular update, definitely no accidents here...
9a9add8 (origin/master) Added .gitignore
81912ba Corrected spelling error
2) We want to return to the commit: 9a9add8 (origin/master)
git reset 9a9add8
3) Now let's again check the commit.
git log --oneline
9a9add8 (HEAD -> master, origin/master) Added .gitignore
81912ba Corrected spelling error
Warning: Messing with the commit history of a repository can be dangerous.
It is usually ok to make these kinds of changes to your own local repository.
However, you should avoid making changes that rewrite history to remote repositories,
especially if others are working with them.
24) Git Undo Reset
Even though the commits are no longer showing up in the log, it is not removed from Git.
If you know the commit hash you can reset to it:
Example
=========>
git reset e56ba1f
Now let's check the log again:
git log --oneline
e56ba1f (HEAD -> master) Revert "Just a regular update."
52418f7 Just a regular update, definitely no accidents here...
9a9add8 (origin/master) Added .gitignore
81912ba Corrected spelling error
25) Git Amend
==============>
Git commit --amend ==> is used to modify the most recent commit.
It combines changes in the staging environment with the latest commit, and creates a new commit.
Let's update the README.md and commit:
Example
========>
git commit -m "Adding plines to reddme"
Now let's check the log:
git log --oneline
07c5bc5 (HEAD -> master) Adding plines to reddme
9a9add8 (origin/master) Added .gitignore
git commit --amend -m "Added lines to README.md"
And re-check the log:
git log --oneline
eaa69ce (HEAD -> master) Added lines to README.md
9a9add8 (origin/master) Added .gitignore
What is GitHub?
==================>
Git is not the same as GitHub.
GitHub makes tools that use Git.
GitHub is the largest host of source code in the world, and has been owned by Microsoft since 2018.