# Installation

## Introduction

Before we start learning, we'll need to install Ruby first. This section is where you could potentially encounter a lot of errors.

Before continuing, let's review a few best practices to keep in mind:

* Copy and paste the commands to avoid typos.
* Follow the directions closely, and don't skip over any sections.
* **Do NOT use `sudo`.** Failing to follow this can cause a lot of headaches, and never run as the `root` user. In some instances you might see a message in the terminal telling you to use sudo and install something with `apt` . Ignore that and follow *our* instructions for now.

Now, let's get started!

## Ubuntu / Xubuntu

### Step 1: Install updates, packages and libraries

Before we can install Ruby, we need to install some base packages.

#### **Step 1.1: Open the terminal**

We'll use the terminal to install all of the programs.

If you're using Ubuntu or Xubuntu, simply press `Ctrl + Alt + T` to open the terminal. (This may work in other Linux distributions; you'll have to try!)

**Quick tip:** In Linux, you can copy from the terminal with `ctrl + shift + c` and paste with `ctrl + shift + v`.

#### **Step 1.2: Update Linux**

The rest of the installation will take place inside the terminal window.

First, we need to make sure your Linux distribution is up to date. Run these commands one by one. Because these commands use `sudo`, you will have to enter your password in order for them to run. When typing your password, you may not get any visual feedback, but rest assured that your password is being entered. Once you're done typing your password, press `enter`.

```bash
sudo apt update
sudo apt upgrade
```

When it prompts you, press `y` and then `enter`.

#### **Step 1.3: Install packages and libraries**

Next, you need to install some required packages that do not come preinstalled. Be sure to copy and paste this command.

```bash
sudo apt install gcc make libssl-dev libreadline-dev zlib1g-dev libsqlite3-dev
```

When it prompts you, press `y` and then `enter`. You may or may not have to type your password after pressing `enter`.

### Step 2: Install Ruby

Now you're ready to install Ruby. We're going to use a tool called `rbenv`, which makes it easy to install and manage Ruby versions.

#### **Step 2.1: Install rbenv**

First, you need to clone the rbenv repository using `git`, which is a version control program you installed with the last command. You will become more familiar with this program later on.

```bash
git clone https://github.com/rbenv/rbenv.git ~/.rbenv
```

Next, we'll add some commands to allow rbenv to work properly. We can use the Linux `echo` command to make it easy.

Note: Run these commands one by one in sequence. They will not provide any output if done properly. Again, be sure to copy and paste these commands.

```bash
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(rbenv init -)"' >> ~/.bashrc
exit
```

After running the final `exit` command, you will need to close and open a new terminal (see Step 1.1 above).

Next, you need to install `ruby-build` to help compile the Ruby binaries. Run these commands in the terminal to create a directory for the ruby-build plugin and then download it to the proper directory.

```bash
mkdir -p "$(rbenv root)"/plugins
git clone https://github.com/rbenv/ruby-build.git "$(rbenv root)"/plugins/ruby-build
```

Finally, run...

```bash
rbenv -v
~
```

...from your terminal to verify that `rbenv` has been installed correctly. You should get an output with a version number **similar** to this:

```bash
rbenv 1.1.2-2-g4e92322
```

#### **Step 2.2: Install Ruby**

It's finally time to install Ruby using `rbenv`!

Inside the terminal, run this command:

```bash
rbenv install 2.7.2 --verbose
```

This command will take 10-15 minutes to complete. The `--verbose` flag will show you what's going on so you can be sure it hasn't gotten stuck. While it installs, take this time to watch [this video](https://youtu.be/X2CYWg9-2N0) or to get a glass of water.

When the last command is finished, set the Ruby version and verify that it's working:

```bash
rbenv global 2.7.2
```

Then,

```bash
ruby -v
```

The above command should return something similar to this:

```bash
ruby 2.7.2pxx (20xx-xx-xx revision xxxxx) [x86_64-linux]
```

where x represents the version available at the time you installed Ruby.

Well done! Pat yourself on the back! The hard part is done, and it's time to move on to the next lesson!

## MacOS

### Step 1: Install packages and libraries

Before we can install Ruby, we need to install some base packages. We will use the terminal to install all of the programs.

#### **Step 1.1: Open the terminal**

In your Applications folder, find "Utilities" and double click "Terminal". Alternatively, using Spotlight (`CMD + Space`) or Launchpad, type "Terminal".

The rest of the instructions are done inside this terminal window.

#### **Step 1.2: Install Xcode**

First, you need to install Xcode, which is a program provided by Apple for programming. Xcode will install many programs that are needed for Ruby and Git and should take 10-15 minutes to install.

Type `xcode-select --install` in your terminal and press `enter`. You may need to click "Install" when prompted.

#### **Step 1.3: Install Homebrew**

The next program you need to install is [Homebrew](https://brew.sh/), which makes it easy to install other programs you'll need. From inside the terminal, type the following:

```bash
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
```

You will be prompted to enter your password. When typing your password, you may not get any visual feedback, but rest assured that your password is being entered. Once you're done typing your password, press `enter`.

Congratulations! You've installed the prerequisites!

### Step 2: Install Heroku

Heroku is a place to host your Rails applications.

```bash
brew install heroku/brew/heroku
```

This command will install the command line interface for Heroku, a free website that can host your Ruby on Rails applications. You'll learn more about this later.

### Step 3: Install Ruby

Now you're ready to install Ruby. We're going to use a tool called `rbenv`, which makes it easy to install and manage Ruby versions.

#### **Step 3.1: Install rbenv**

To install `rbenv`, run the following in your terminal:

```bash
brew install rbenv
```

Then, run this command:

```bash
rbenv init
```

You should see one of two messages after the command has run.

Either:

```bash
# Load rbenv automatically by appending
# the following to ~/.bash_profile:

eval "$(rbenv init -)"
```

Or:

```bash
# Load rbenv automatically by appending
# the following to ~/.zshrc:

eval "$(rbenv init -)"
```

You'll do as it suggests by running either of the following commands in the terminal.

If the previous message stated you should append to your bash\_profile then run:

```bash
echo 'eval "$(rbenv init -)"' >> ~/.bash_profile
```

Otherwise if it mentioned zshrc then run:

```bash
echo 'eval "$(rbenv init -)"' >> ~/.zshrc
```

You'll notice nothing happened in the terminal. That's okay and is typical response for many terminal commands. At this point, take note of the page and step number you are on, close everything, do a full reboot and log back into your profile. After logging back in, re-open the terminal (see Step 1.1).

#### **Step 3.3: Install Ruby**

We can now (finally) install Ruby! Our curriculum currently uses version 2.7.2, which will allow you to complete this path's materials and content without error. We upgrade the material to accommodate newer versions as necessary. Without further ado, let's get going!

```bash
rbenv install 2.7.2 --verbose
```

This command will take 10-15 minutes to complete. The `--verbose` flag will show you what's going on so you can be sure it hasn't gotten stuck. While it installs, take this time to watch [this video](https://www.youtube.com/watch?v=X2CYWg9-2N0) or to get a glass of water.

Once Ruby is installed, you need to tell rbenv which version to use by default. Inside the terminal, type:

```bash
rbenv global 2.7.2
```

You can double check that this worked by typing `ruby -v` and checking that the output says version 2.7.2:

```bash
$ ruby -v
ruby 2.7.2pxx (20xx-xx-xx revision xxxxx)
```

If you don't see the output above, log off and log back on, then try again.

Well done! Pat yourself on the back! The hard part is done, and it's time to move on to the next lesson!

## **Extras**

If you're using Visual Studio Code as your IDE, you can install the "Ruby" extension which will provide you with semantic highlighting and formatting support. This is optional, but it is a quick install; go to the "Extensions" tab in VSC (Ctrl+Shift+X), search "Ruby", and click install on the first one. Congratulations, the extension is now installed (you can also uninstall the extension from here).

If you are using a different IDE, a quick Google search such as "Ruby programming extensions for (your IDE here)" should provide you with the resources to get started. Free support extensions can help make your programming go more smoothly, and there are tons of extensions for all languages (not just Ruby).


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