Setup: The Terminal on a Mac
Open the Terminal app, meet zsh, the shell it opens, then add Homebrew, bash 5 and bats, so every script and exercise check in this course runs on your Mac.
Novice · Unix · Linux · Updated
After this lesson you can
- Open the Terminal app on a Mac and recognize zsh's % prompt
- Choose the Homebrew commands that add bash 5 and bats to a Mac, and check each one with --version
Key takeaways
- The Terminal app is in Applications, then Utilities. Cmd+Space, then typing Terminal, is the fastest way to open it.
- A Mac's Terminal opens zsh, whose prompt ends in %. You type this course's commands into zsh; where it differs from bash, a lesson says so.
- Homebrew is a package manager for the Mac. brew install adds command-line tools by name.
- macOS comes with bash 3.2, from 2006. brew install bash adds bash 5 for your scripts, and bats-core runs the exercise checks.
A class says "open a terminal and run…", a tutorial starts with a command, and you're on a Mac. Good news: the terminal is already on your computer, and so is a shell. This lesson opens it, then adds three free tools the course uses, in about twenty minutes, once. (On Linux or Windows? Setup: The Terminal on Linux or Setup: The Terminal on Windows is your lesson instead.)
Open the Terminal app
Press Cmd+Space to open Spotlight, type Terminal, and press Enter. You can also find it in Finder, under Applications, then Utilities.
You'll open it often, so keep it in the Dock: while it's open, Control-click its icon in the Dock, then choose Options, then Keep in Dock.
zsh, the shell your Mac opens
The window shows one line, something like sam@Sams-MacBook-Air ~ %: your user name, your computer's name, ~ (read "tilde", your home folder) and a %. That line is the prompt, and the % means "ready: type a command".
The program that reads what you type is called a shell, and a Mac's is zsh (read "zee shell"), the default since 2019. zsh and bash are close cousins: nearly every command in this course works the same in both, and where zsh differs, the lesson has a short note. You don't need to change anything. To see your shell's name, type this and press Enter:
echo $SHELL
It prints /bin/zsh. ($SHELL is read "the value of SHELL"; Shell, Terminal, Prompt explains the three words.)
Homebrew: installing tools by name
macOS has no built-in way to add command-line tools. Homebrew is the free package manager most Mac developers use: brew install, followed by a tool's name, downloads it and sets it up.
Its official site, brew.sh, shows one line to copy into your terminal. Before you press Enter, know what it does: it installs software, so it asks for your Mac's password, the one you sign in with. Nothing shows on the screen while you type it; type it anyway and press Enter. It may also offer to install Apple's Command Line Tools; say yes. It takes a few minutes.
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
When it finishes, read its last lines. If they include Next steps with a few commands (they do on Macs with Apple chips), those commands let your terminal find brew: copy them from your own screen and run them. Then check:
brew --version
It prints Homebrew and a version number. If it says command not found instead, the Next steps lines haven't run yet. A good habit for life: copy installer lines only from the tool's own website.
bash 5 for your scripts, and bats
Your Mac has bash too, but an old one. Type bash --version, and its first line says version 3.2.57: bash 3.2 came out in 2006, and Apple stopped updating it when bash's license changed. This course's scripts use features added since then, so add bash 5, along with bats-core, the program that runs the exercise checks:
brew install bash bats-core
Close the Terminal window, open a new one, and check both:
bash --version
bats --version
The first line of bash --version now says version 5.3 or newer, and bats --version prints Bats and a version number, such as Bats 1.14.0.
Your Terminal still opens zsh, and that's what you want. You type commands in zsh, and every script in this course starts with a line, #!/usr/bin/env bash, that runs it in bash 5. Leave your Mac's default shell as it is.
Make your practice folder
Every lesson works in one practice folder, terminal-practice, in your home folder, so nothing you try touches your real files. Make it, go into it, and ask where you are:
mkdir -p ~/terminal-practice
cd ~/terminal-practice
pwd
pwd prints /Users/, your user name and /terminal-practice: for Sam, /Users/sam/terminal-practice. mkdir makes a folder (Module 2 covers it), cd moves you into it, and pwd says where you are (both are in the next chapter). Now type open . and Finder opens the same folder: two doors into one place.
Check yourself
2 questions to try on the lesson page.
So what
Your Mac now has everything this course uses: the Terminal and zsh for typing commands, Homebrew for installing tools, bash 5 for scripts and bats for exercise checks. You set it up once, and it's ready for every lesson.