1 - Basic Linux Commands

What are we learning?

Hopefully by the end of this lesson you will be able to:

• Install Linux on a Chromebook (basically turn on dev mode)

• Update Debian-based linux

• Use some basic Linux commands to talk to the Kernel through the BASH shell

The Lesson

• What is an Operating System Kernel

  • "A kernel is a computer program at the core of a computer's operating system that always has complete control over everything in the system."  (wikipedia)

• What is a Terminal or Console

  • It "... provides a way for the kernel and other processes to send text output to the user, and to receive text input from the user. The user typically enters text with a computer keyboard and reads the output text on a computer monitor." (wikipedia)

• What is a Shell

  • "... a computer program that exposes an operating system's services to a human user or other programs. In general, operating system shells use either a command-line interface (CLI) or graphical user interface (GUI), depending on a computer's role and particular operation. It is named a shell because it is the outermost layer around the operating system."  (wikipedia)

So - you use a Shell in a Terminal or Console to communicate with the Kernel.

Technically the colours and "windows" you see in Windows, Mac OS, iOS, Android, etc... are all a "Shell" that allows communication with the Kernel.

• The most common shells are BASH and Command Prompt (CMD).

  • There are many (many) shells available for *nix operating systems. Most are derivatives of SH or BASH.

Turn On Linux in ChromeOS

I would love to have us all install a full Linux distribution but that's not really part of the course. Thankfully ChromeOS is built on top of the Linux kernel (that's right - ChromeOS is another shell).

• Grab a class Chromebook (you will be assigned a number)

• Login using your school account

• Follow the instructions in class to gain access to the Linux features of your Chromebook

• Once you are in the terminal (black screen with green text) full screen it with F11

• Ask for a list of updates using the Advanced Package Tool (apt):  sudo apt update

• Install the updates using the apt package manager:  sudo apt -y upgrade

  • What is that sudo thing?

Some Basic BASH Commands

• ls → list (ls)

• mkdir → make an empty directory (mkdir ICS4U)

• cd → change directory (cd ICS4U)

  • inside here create a "Unit0" directory and then inside that a "Lesson1" directory

• Things to note:

  • cd ..  will go back one directory

  • cd ~  will change to your home directory

  • cd /  will change to the "root" directory

• pwd → print working directory (what directory are you currently in?)

• touch myfirstscript.sh → create an empty file called myfirstscript.sh

  • Now create another file called "some_file.txt"

• rm → remove (rm some_file.txt) to delete a file

• mv → move or rename a file (mv myfirstscript.sh hello.sh) 

• echo → print text or data (echo Hi Mom!)