UNIX/Linux Quiz 1

Ada Lovelace (1852)

Ada Lovelace (1852)

Regarded as the first computer programmer

Charles Babbage (1871)

• First digital computer

Alan Turing (1954)

• Created the Enigma Code Breaker for WWII

• Turing machine – Every computer program.

• Turing Test – How to define intelligence?

  • Artificial Intelligence

John von Neumann (1957)

Von Neumann Architecture

Analog vs. Digital

• Analog: continuous computing

  • floating point numbers: an approximation of an infiinite amount of values; constant computing

  • values between on/off, more precuse

  • mechanical

• Digital: switches like on/off, 1/0, high/low

  • transistors

programming languages

• Interpreted or Compiled

  • Slow vs. Fast

  • Intuitive vs. Less intuitive

  • Python interpreted vs. C/C++ compiled

• Abstraction

  • High-level-language: Python/C++

  • Assembly: Fundamental instructions

  • Machine Code: Binary (Ewww!)

UNIX

• created in 1969 and originally written in Assembly

Linux

• UNIX-like

• Created by Linus Torvalds in 1991

• Focus on Linux with Ubuntu

4 components

• Hardware

  • CPU, Memory, Storage, I/O Devices, etc.

• Kernel

  • Drivers, memory management, process handling, security, etc.

• Shell/Commandline (what we are focusing on)

  • Bash, Zsh, etc.

• Software

  • GUI (Graphical User Interface), etc.

opening and closing the terminal

• ‘ctrl + alt + t’ opens on some linux displays

• ‘exit’ - exits the terminal or session

• ‘tab’ - attempt to autocomplete and shows matching pattern

• ‘up’ or ‘down’ arrow keys - see recent commands

Directory

like a folder on your computer

File

file, like you are used to but in purely TEXT format

File system

the structure/hierachy of all files and directories

Parent

up or proceding folder/directory

child

down or after folder/directory

working directory

where you are currently located in the file system

gedit command

opens a plain text file in the terminal

commandline interface

the name for the Terminal interface software

path

the locations of a file or directory in the file system’s heirarchy; the way/directions to get to some file

• ‘.’ - single dot refers to place you currently located

• ‘..’ - referes to the parent or upper directory

• ~ tilde refers to home directory

• dont have to use / for pathway when file is already in that area or folder

root directory

the highest level/top of the file system; can be accessed by typing ‘/’

home directory

where all your personal files and directories live called

• use ~ to open a terminal in your home directory

ls (list)

• use along with a path to list the files/directories of that location

• terminal command do we use to show files/directories

• ‘ls ..’ lists the contents of parent

• ‘ln path’ lists the contents of specified directory

pwd (print working directory)

to get the exact location where you are in the file system we use to see our current global/absolute location.

cd (change directory)

• use along with a path to move around in the file-system

• this terminal command is the same as double-clicking on a folder/directory in the GUI to navigate around from one folder/directory to another

• can type ‘cd ..’ to go to the previous two directories that we had

• ‘cd .’ to go to parent

• cd path for specific path

mv (move)

command to move a file to another location in the file-system or rename the file

cp (a copy)

command to duplicate a file and optionally rename the file at the same time

(srcfile = sourcefile)

mkdir dirname (make directory)

creates a directory named dirname in the current working directory

touch filename

creates an empty file or updates timestamp

cat filename

prints the entire contents of file to the terminal

less filename

interactively view a file, use up and down arrows and q to quit

view filename

same as less but in a text editor. type :q and enter to quit

man command (manual)

gives you a detailed list and explanation of the command that you manned

clear

clears the terminal

echo

prints what you give it to stdout (standard output) by default

ex. echo hello world

rm (remove)

rm filename deletes a file

NONREVERSIBLE!!!!

global/absolute pathway

the permanent pathway of where something is

path always begins from the absolute start of your hard drive and describes every step you must take through the filesystem to end up at the target location