Summary and Schedule

The Unix shell has been around longer than most of its users have been alive. It has survived because it’s a powerful tool that allows users to perform complex and powerful tasks, often with just a few keystrokes or lines of code. It helps users automate repetitive tasks and easily combine smaller tasks into larger, more powerful workflows.

Use of the shell is fundamental to a wide range of advanced computing tasks, including high-performance computing. These lessons will introduce you to this powerful tool.

Prerequisite

Prerequisites

This lesson guides you through the basics of file systems and the shell. If you have stored files on a computer at all and recognize the word “file” and either “directory” or “folder” (two common words for the same thing), you’re ready for this lesson.

The actual schedule may vary slightly depending on the topics and exercises chosen by the instructor.

Download files

You need to download some files to follow this lesson.

  1. Download shell-lesson-data.zip and move the file to your Desktop.
  2. Unzip/extract the file. Let your instructor know if you need help with this step. You should end up with a new folder called shell-lesson-data on your Desktop.

Install software

Callout

Installation instructions

Follow these install instructions according to your Operating System (OS).

Please install Git for Windows using the instructions below.

  • Download the Git for Windows installer installed.
  • Run the installer and follow the steps below:
    • Click on “Next” four times (two times if you’ve previously installed Git). You don’t need to change anything in the Information, location, components, and start menu screens.
    • From the dropdown menu, “Choosing the default editor used by Git”, select “Use the Nano editor by default” (NOTE: you will need to scroll up to find it) and click on “Next”.
    • On the page that says “Adjusting the name of the initial branch in new repositories”, ensure that “Let Git decide” is selected. This will ensure the highest level of compatibility for our lessons.
    • Ensure that “Git from the command line and also from 3rd-party software” is selected and click on “Next”. (If you don’t do this Git Bash will not work properly, requiring you to remove the Git Bash installation, re-run the installer and to select the “Git from the command line and also from 3rd-party software” option.)
    • Select “Use bundled OpenSSH”.
    • Ensure that “Use the native Windows Secure Channel Library” is selected and click on “Next”.
    • Ensure that “Checkout Windows-style, commit Unix-style line endings” is selected and click on “Next”.
    • Ensure that “Use Windows’ default console window” is selected and click on “Next”.
    • Ensure that “Default (fast-forward or merge) is selected and click”Next”
    • Ensure that “Git Credential Manager” is selected and click on “Next”.
    • Ensure that “Enable file system caching” is selected and click on “Next”.
    • Click on “Install”.
    • Click on “Finish” or “Next”.
  • If your “HOME” environment variable is not set (or you don’t know what this is):
  • Open command prompt (Open Start Menu then type cmd and press Enter)
  • Type the following line into the command prompt window exactly as shown:

    setx HOME “%USERPROFILE%”

  • Press Enter, you should see SUCCESS: Specified value was saved.
  • Quit command prompt by typing exit then pressing Enter

If you prefer, here is a video tutorial with the instructions: https://www.youtube.com/watch?v=339AEqk9c-8

For a Mac computer running macOS Mojave or earlier releases, the default Unix Shell is Bash. For a Mac computer running macOS Catalina or later releases, the default Unix Shell is Zsh. Your default shell is available via the Terminal program within your Utilities folder.

To open Terminal, try one or both of the following:

  • In Finder, select the Go menu, then select Utilities. Locate Terminal in the Utilities folder and open it.
  • Use the Mac ‘Spotlight’ computer search function. Search for: Terminal and press Return.

To check if your machine is set up to use something other than Bash, type echo $SHELL in your terminal window.

If your machine is set up to use something other than Bash, you can run it by opening a terminal and typing bash.

How to Use Terminal on a Mac

The default Unix Shell for Linux operating systems is usually Bash. On most versions of Linux, it is accessible by running the Gnome Terminal or KDE Konsole or xterm, which can be found via the applications menu or the search bar. If your machine is set up to use something other than Bash, you can run it by opening a terminal and typing bash.

Open a new shell

After installing the software

  1. Open a terminal. If you’re not sure how to open a terminal on your operating system, see the instructions below.
  2. In the terminal type cd then press the Return key. This step will make sure you start with your home folder as your working directory.

In the lesson, you will find out how to access the data files in this folder.

Callout

Where to type commands: How to open a new shell

The shell is a program that enables us to send commands to the computer and receive output. It is also referred to as the terminal or command line.

Some computers include a default Unix Shell program. The steps below describe some methods for identifying and opening a Unix Shell program if you already have one installed. There are also options for identifying and downloading a Unix Shell program, a Linux/UNIX emulator, or a program to access a Unix Shell on a server.

If none of the options below address your circumstances, try an online search for: Unix shell [your computer model] [your operating system].

Computers with Windows operating systems do not automatically have a Unix Shell program installed. In this lesson, we encourage you to use an emulator included in Git for Windows, which gives you access to both Bash shell commands and Git.

Once installed, you can open a terminal by running the program Git Bash from the Windows start menu.

For advanced users:

As an alternative to Git for Windows you may wish to Install the Windows Subsystem for Linux which gives access to a Bash shell command-line tool in Windows 10 and above.

Please note that commands in the Windows Subsystem for Linux (WSL) may differ slightly from those shown in the lesson or presented in the workshop.

For a Mac computer running macOS Mojave or earlier releases, the default Unix Shell is Bash. For a Mac computer running macOS Catalina or later releases, the default Unix Shell is Zsh. Your default shell is available via the Terminal program within your Utilities folder.

To open Terminal, try one or both of the following:

  • In Finder, select the Go menu, then select Utilities. Locate Terminal in the Utilities folder and open it.
  • Use the Mac ‘Spotlight’ computer search function. Search for: Terminal and press Return.

To check if your machine is set up to use something other than Bash, type echo $SHELL in your terminal window.

If your machine is set up to use something other than Bash, you can run it by opening a terminal and typing bash.

How to Use Terminal on a Mac

The default Unix Shell for Linux operating systems is usually Bash. On most versions of Linux, it is accessible by running the Gnome Terminal or KDE Konsole or xterm, which can be found via the applications menu or the search bar. If your machine is set up to use something other than Bash, you can run it by opening a terminal and typing bash.