# Setting up Git ## Version control Git is a very popular version control system. You'll become very familiar with this piece of software throughout the curriculum, so don't worry too much about understanding it at this point. There are multiple lessons focused on Git later in the curriculum. GitHub is a service that allows you to upload your code using Git and to manage your code with a nice web interface. GitHub and Git are not the same thing or even the same company. ## Step 1: Install Git Click the Operating System you have chosen below: ### Linux users ### **Step 1.1: Update the system** Run these commands in the terminal to update the Linux system: ```bash sudo apt update sudo apt upgrade ``` ### **Step 1.2: Install git** It's likely you have `git` installed already, but to make sure that we have the most up to date version of git, run the following commands: ```bash sudo add-apt-repository ppa:git-core/ppa sudo apt update sudo apt install git ``` ### **Step 1.3: Verify version** Make sure your git version is **at least** 2.28 by running this command: ```bash git --version ``` If the version number is less than 2.28, follow the instructions again. ### MacOS users ### **Step 1.0: Install Homebrew** First, you'll need to install Homebrew. Make sure you have checked the requirements [here](https://docs.brew.sh/Installation#macos-requirements). Once you meet the requirements, copy and paste the following into your terminal: ```bash /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)" ``` ### **Step 1.1: Update Git** MacOS already comes with a version of Git, but you should update to the latest version. In the terminal, type ```bash brew install git ``` This will install the latest version of Git. Easy, right? ### **Step 1.2: Verify version** **Open a new terminal window** and then make sure your git version is **at least** 2.28 by running this command: ```bash git --version ``` If the version number is less than 2.28, follow the instructions again. If you are encountering a `no formulae found in taps` error: 1. Run `brew doctor` 2. You must run each command line snippet that Homebrew provides in order to repair your installation of Homebrew, including `brew cleanup` at the end. 3. Run `brew install git`, **open a new terminal window**, then check your version of Git, which should now be the latest version. ## Step 2: Configure Git and GitHub ### **Step 2.1: Setup Git** For Git to work properly, we need to let it know who we are so that it can link a local Git user (you) to GitHub. When working on a team, this allows people to see what you have committed and who committed each line of code. The commands below will configure Git. Be sure to enter your own information inside the quotes (but include the quotation marks)! ```bash git config --global user.name "Your Name" git config --global user.email "yourname@example.com" ``` GitHub recently changed the default branch on new repositories from `master` to `main`, change the default branch for Git using this command: ```bash git config --global init.defaultBranch main ``` To enable colorful output with `git`, type ```bash git config --global color.ui auto ``` To verify things are working properly, enter these commands and verify that the output matches your name and email address. ```bash git config --get user.name git config --get user.email ``` ### **Step 2.2: Create a GitHub account or sign in** Go to [GitHub.com](https://github.com/) and create an account! If you already have an account, sign in. You do not need to use the same email address you used before, but it might be a good idea to use the same one to keep things simple. ### **Step 2.3: Create an SSH key** An SSH key is a cryptographically secure identifier. It's like a really long password used to identify your machine. GitHub uses SSH keys to allow you to upload to your repository without having to type in your username and password every time. First, we need to see if you have an SSH key already installed. Type this into the terminal: ```bash ls ~/.ssh/id_rsa.pub ``` If a message appears in the console containing the text "No such file or directory", then you do not yet have an SSH key, and you will need to create one. If no message has appeared in the console output, you already have a key and can proceed to step 2.4. To create a new SSH key, run the following command inside your terminal. The `-C` flag followed by your email address ensures that GitHub knows who you are. **Note:** The angle brackets (`< >`) in the code snippet below indicate that you should replace that part of the command with the appropriate information. Do not include the brackets themselves in your command. For example, if your email address is `test@example.com`, then you would type `ssh-keygen -C test@example.com`. You will see this convention of using angle brackets to indicate placeholder text used throughout the curriculum and other coding websites, so it's good to be familiar with what it means. ```bash ssh-keygen -C ``` * When it prompts you for a location to save the generated key, just push `Enter`. * Next, it will ask you for a password; enter one if you wish, but it's not required. ### **Step 2.4: Link your SSH key with GitHub** Now, you need to tell GitHub what your SSH key is so that you can push your code without typing in a password every time. First, you'll navigate to where GitHub receives our SSH key. Log into GitHub and click on your profile picture in the top right corner. Then, click on `Settings` in the drop-down menu. Next, on the left-hand side, click `SSH and GPG keys`. Then, click the green button in the top right corner that says `New SSH Key`. Name your key something that is descriptive enough for you to remember where it came from. Leave this window open while you do the next steps. Now you need to copy your public SSH key. To do this, we're going to use a command called [`cat`](http://www.linfo.org/cat.html) to read the file to the console. (Note that the `.pub` file extension is important in this case.) ```bash cat ~/.ssh/id_rsa.pub ``` Highlight and copy the output, which starts with `ssh-rsa` and ends with your email address. Now, go back to GitHub in your browser window and paste the key you copied into the key field. Then, click `Add SSH key`. You're done! You've successfully added your SSH key! ### **Step 2.5 Testing your key** Follow the directions in [this article from GitHub](https://help.github.com/en/articles/testing-your-ssh-connection) to verify your SSH connection **(Don't forget to omit the `$` when you copy and paste the code!)**. You should see this response in your terminal: **Hi username! You've successfully authenticated, but GitHub does not provide shell access.** Fear not the part about not being provided shell access. If you see this message, you've successfully added your SSH key and you can move on. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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