If you follow through this workshop, you will receive a unique animal avatar 🐱 generated from your user name. Trust me, it’s kinda NFT; it's just not on a block chain.
⌛ Estimated Length: 25 minutes
👤 Author: Jerry Jia
We mostly use mouse, trackpad, and graphical user interfaces (GUI) in nowadays. In fact, there’s another way you can do things on a computer that makes you look like a pro: CLI.
CLI stands for Command Line Interface. It’s a quick and powerful interface for developers to communicate with computers to accomplish a wider set of tasks.
To begin, you need to open your shell in a terminal. A shell program wraps around the operating system to expose a human-friendly command line interface. And the terminal displays a graphical interface for users to interact with shells.
Here’s a quick recap:
- Command Line Interface (CLI): receives text commands from a user to communicate with a computer; alternative to graphical user interface (GUI)
- Shell: a program that exposes an operating system's services to a human user or other programs
- Terminal/Console: a program that displays a GUI for users to interact with the CLI
Each operating system ships with different shells and terminals. Some are easier to work with while some are not.
Please install VSCode as well.
press command + space to launch Spotlight Search, type terminal.app and hit return.
- The default shell on MacOS is called
zsh
Option 1: WSL (Recommended) - Follow this installation guide
Windows Subsystem for Linux (WSL) allows users to install a Linux distribution (e.g. Ubuntu) on a Windows machine. It provides the best overall developer experience with a native Linux environment. Also, Most servers run Linux as well, so it’s good to familiarize yourself with it.
Option 2: Git Bash
Git Bash bundles many UNIX tools with the most commonly used bash shell. It provides the nearest experience to Linux on Windows and was the go-to option before WSL was introduced.
- Download
git - Follow these instructions to make sure that
git bashis installed during the process - Press
windows,typegit bashand pressenter
Option 3: PowerShell
Powershell is the most commonly used shell program on Windows, but many of its syntax is different with Linux’s. So, some of the commands we will use in the following steps won’t work.
- Press
windows, typepowershelland pressenter
You probably know these stuff already. Kudos to you.
echo "hello world"You probably know what this means. echo just prints the string that follows it.
cd ~cd = change directory. This is the command that you will use very often for navigation.
-
~here stands for your home directory. Every user in the system has access to own home directory but usually not others’. -
You can open the current directory in the GUI
- Windows:
explorer.exe . - Mac:
open .
.here stands for the current directory - Windows:
pwdThis prints your current path. It should be something like /home/<your-username>
You can use whoami to get your user name as well.
lsNow you will see what’s in your home directory
- For more verbose output, use
ls -la-luse a long listing format that includes file permissions, owner, date, etc.-aincludes hidden files (e.g. file names that start with a dot.)
mkdir workshopThis creates a folder (directory) in the current location. Now, if you ls again, you should see the workshop folder in the output.
cd workshopNow, you are in the workshop folder.
touch helloThis creates an empty file called hello.
echo "hello world" > hello> redirects the output from echo to the file hello.
cat helloYou can use head or tail to view only a portion of the file.
- Add
-n NUMBERto view a certain number of lines only. For example,tail -n 10 server.logonly prints the last 10 lines ofserver.log.
cp hello worldcp = copy. Now with ls, you should see two files in the current directory.
mv world universemv actually means move. Moving the world file to universe is renaming it.
You can use this command to move files, too (surprise, surprise)
mkdir metaverse
mv universe metaverse
cd metaverse
lsWe’ve just moved universe into metaverse and entered metaverse to verify it.
rm universeNow use ls to verify that it’s removed.
cd .... = parent directory. Now we’re back in the workshop directory.
rmdir metaverseHowever, if this folder is not empty, you will need to use rm -r
-rstands for recursive.- Add
-fto force remove all files without needing to confirm each action.
PRO TIP: be cautious with
rm -rf. Something likerm -rf /could break your system.
man curlThis opens the manual for curl. You can use your arrow key to scroll up and down or type q to quit. This is an alternative to Googling this command.
curl http://example.com --output e.htmlThis downloads the content of this website to a file. You can use ls and cat/head/tail to see what you have just downloaded.
cat e.html | grep h1|pipes the output of the previous command to the next.grephere searches for a line that containsh1in its input.
You should see <h1>Example Domain</h1> in the output.
clearNow everything should be gone!
You can use your up & down arrow keys to find the previous commands you typed.
history will print all your history commands.
With what we’ve just learned, you can use grep to search for a command you typed history.
history | grep "curl"| Command | Description | Example |
|---|---|---|
| echo | Print string | echo “hello world” |
| ls | List the directory (folder) system. | ls -la |
| cd pathname | Change directory (folder) in the file system. | cd ~ |
| cd .. | Move one level up (one folder) in the file system. | cd .. |
| touch | Create an empty file | touch hello |
| cp | Copy a file. | cp hello world |
| mv | Move (rename) a file. | mv world universe |
| mkdir | Creates a new directory (folder). | mkdir metaverse |
| rmdir | Remove a directory (folder). | rmdir metaverse |
| clear | Clears the CLI window. | clear |
| man command | Shows the manual for a given command. | man curl |
| curl | Transfer data to/from a URL | curl https://ipapi.co/json |
| history | View shell command history | history |
| grep | Search for lines that contains certain text | history | grep curl |
If you are ever confused about what a command does, explainshell.com can help you figure it out.
sudheerj/Linux-cheat-sheet: List of Linux commands (github.com)
chubin/cheat.sh: the only cheat sheet you need (github.com)
Linux Command Cheat Sheet (guru99.com)
Git is free and open source software for distributed version control.
Imagine writing a final paper with 3 classmates. Each of you writes a part of it and send multiple copies at different times to different people for edits. You will need to merge all the paragraphs and edits, likely conflicting, into one final draft - if that sounds chaotic already, Git is to your rescue.
- Track changes
- Document changes with commits
- Branch from a commit for changes that won’t affect others
- Merge different branches onto each other
- Manage projects with repositories on a remote
- Clone a project to work on a local copy
- Pull the latest version of the project to a local copy
- Push local updates to the main project
GitHub is a private company owned by Microsoft. It is currently hosts the most number of git repositories and provides the best overall user experience for free. Alternatives include GitLab, Bitbucket, etc.
Set your git user name and email consistent to your GitHub account.
git config --global user.name "YOUR USERNAME"
git config --global user.email "YOUR EMAIL"SSH is the most secure and convenient way to connect your local machine to GitHub.
Checkout this GitHub Docs for using it.
In the workshop folder, run
git initThis initializes the current directory as a Git repository. A hidden .git folder is created to store the information. To delete the repository, remove the .git folder with rm -rf .git.
git statusThis tells you what’s going on in this repository. Now, the hello file should appear as untracked.
git add helloThis allows git to start tracking this file. Now, type git status again to confirm this.
You can use git add * to add all files or git add . to include folders as well.
git diff --cachedYou can see what changes you have made to the files being tracked by git.
git commit -m "added hello"This creates a commit of your changes with a message. Commits can be thought of as snapshots or milestones along the timeline of a Git project.
Source: Git Commit | Atlassian Git Tutorial
It’s a good practice to write a descriptive message with each commit to tell others and remind yourself about what changes are made.
git logYou can now see that your commit is recorded in the logs. Press q to exit.
git branch -M mainThis renames the current branch to main. Some legacy Git clients uses master as the name for the default branch, which is deprecated due to political correctness.
You can branch off from any commit (snapshot) in Git to make changes that won’t affect others. This creates a tree-like structure shown in the diagram below:
Source: Git Branch | Atlassian Git Tutorial
The default branch is called master or main. It represents the base of a repository or intuitively, root of the tree.
git checkout -b testcheckoutswitches to a different branch and carries all previous commits with it.-bcreates new a branch if none exists yet from the default.
Our new branch should have the previous commit. You can use git log to verify this.
git branchYou’ll get a list of all existing branches. Press q to exit.
To continue, make some changes to hello or create a new file and commit the changes to the test branch.
git switch mainSwitches back to the default branch without carrying the commits.
git merge testYour new commit on the test branch now merges back to the main/master branch! If the changes don’t conflict, you’re done. If there are conflicts, git diff can display them. Once you’ve edited the files to resolve the conflicts, add them and create a new commit.
git branch -D testGiven that the merge is successful, we can now safely delete the test branch.
Go to Create a New Repository (github.com).
After you successfully created a repo, GitHub tells you how you can push an existing repository.
git remote add origin https://github.com/<USERNAME>/<REPO_NAME>.gitremote simply means a place that hosts your repository. Here we create a remote called origin and sets its url to what GitHub provides you.
git push -u origin mainNow, commits and branches in your local repository are pushed to GitHub. You can open the URL to see your code there.
You will learn how to work with a public GitHub repository and receive an animal avatar at the end!
To propose changes to someone else's project, we follow these steps:
- Fork the repository
- Make the fix
- Submit a pull request to the project owner
A fork is a copy of a repository. Forking a repository allows you to freely experiment with changes without affecting the original project.
-
Open Jkker/git-animal
-
Give a star for karma (jk)
-
Click fork
You should now have a copy of this repo in your own account. Copy the URL and clone it locally with this command
git clone https://github.com/<YOUR_USERNAME>/git-animal
cd git-animalTry to do these steps on your own what what we’ve just learned. However, if you run into any problem, feel free to peak at the commands below.
- Create a new branch that has the same name as your GitHub account' user name
- Create a new file with your user name
- Add some content
- Add the file
- Commit the changes
- Push the changes
git checkout -b <BRANCH_NAME>
echo "hello world" > FILE_NAME.txt
git add .
git commit -m "created FILE_NAME.txt"
git push -u origin <BRANCH_NAME>Your changes should now be in your GitHub fork already. For the original repository to accept those changes, you need to submit a pull request. It means that you are requesting the original repository to pull the changes from your repository.
-
Open your repository in the browser
-
Go to the Pull Request tab and click New pull request
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Verify that base repository on the left should be the original repository; head repository on the right should be your fork.
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Write a meaningful title & create the pull request!
Now check out the comment section to receive your animal avatar 🐱.
Dangit, Git!?!: Git is hard: messing up is easy, and figuring out how to fix your mistakes is impossible. This project comes to your rescue if you run into problems with Git.
GitLens - Git supercharged - Visual Studio Marketplace
gitignore - Visual Studio Marketplace
Git - gittutorial Documentation
Git It? How to use Git and Github