linux 101

linux101.md

linux 101

Why?

• understanding the basic's of dealing with the os
• throughout your career you will e.g. seciffcily encounter cli regualary
• cli basics are automation basics

What?

• bios vs os (2m)
• gui vs cli (2m)
• terminal vs cl(i) vs shell (5m)
• cli basic commands & exercises (20-30m)
• package manager (5-10m)
• Q&A (10-15m)

How?

• on your local machine, we will see what we can do

bios vs os

bios

• bios = basic input/output system
• first software to run when powered on
• tests the system hardware components, and loads a boot loader
• firmware used to perform hardware initialization during the booting process (power-on startup)
• past:
  • provide runtime services for operating systems and programs
  • (past) manages data flow between os and attached devices
  • such as: hard disk, video adapter, keyboard, mouse and printer
  • most os's access theses components these days directly

os (operating system)

• collection of software
• abstraction over hardware (cpu, mem, devices)
• runs task (based on different layered software)
• provides cli / gui interface for human interaction
• let's you install other software

gui vs cli

• i/o = input / output

gui

• gui = graphical user interface
• interacted via mouse + keyboard + other higher level input devices
• visual graphical feedback
• mostly takes more effort to handle i/o bec of the restrictions of input devices + gui itself

cli

• cli = command line interface
• interaction via keyboard / i/o streams
• runs in a (virtual) terminal (these days)
• works with i/o streams
• can normally handle more i/o / infrmation processing
• a lot of development related task are normally done with a lot less effort than in a gui
• direct information input

terminal vs cl(i) vs shell

• terminal
  • original pysich
  • these days virtual terminal, e.g. iterm / xterm / ...
• cl(i)
  • what runs in a terminal
  • allows you to do i/o (techniclly on one line :D)
• shell
  • interpreter for bash

cli - basic commands

list of commands

• basic commands:

  • pwd
  • ls
  • cd
    • cd ~
  • touch
  • cat
  • mkdir
  • rmdir
  • rm
  • mv / cp
  • mkdir
  • du / df (-h)
  • top / ps / jobs
  • uname -a
  • history
  • clear

• basic tools

  • top
  • head
  • tail
  • nano
  • grep / grep -v
  • diff
  • man / -h

• rights:

  • su / sudo
  • chmod
  • chown
  • useradd, userdel, passwd

• advanced mentions

  • clear (str + l)
  • ctrl + c (close prog)
  • str + R (search history)
  • awk
  • tar
  • kill + detached start programm using "&" at the end (e.g. tail -f)
  • ping
  • curl

• vi / vim

exercises

• open a terminal. do you know what shell interpreter you are running?

• go to your home directory

• ensrue you are in your home directory

• create files:

  • testfile4
  • testfile5
  • testfile6

• create the following directory structure:

  • create the files and directories (starting with / is ment to be a directory, eg. /a)

   /myhome
   	testfile1
   	testfile2
   	testfile3
   	/testdir
   		/a
   			testfile4
   			testfile5
   			testfile6
   		/b
   			testfile7
   			testfile8
   			testfile9
   		/c
  

• move files from ... to ...

• list the files in directory `` without leaving current directory

• ping google dns

packages

• as already mentioned in the os section, you can install other software
• there are different ways to do so
• on way are package managers
• package managers giving you
  • list of available packages
  • install package
    • installs also it's dependencies
    • install specific version
  • delete packages & dependiencies
  • ability to auto update already installed packages

example

• apt / apt-get
  • htop / iotop / ...
  • docker
  • (virtualbox)
  • (k3s / microk8s)
• wget / curl + chmod +x + mv
  • zsh (or use git for this)
• snap
• appimage