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CSE 391

Syllabus

Introduction to Linux

Slides created by Josh Ervin and Hunter Schafer. �Based off slides made by Marty Stepp, Jessica Miller, Ruth Anderson, Brett Wortzman, and Zorah Fung

Now Playing: Sharou

Before class: Say hi to your neighbor! Introduce yourself and something you’re excited about for this quarter!

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AGENDA

Course introduction

Course introduction and syllabus
Learning remotely using Zoom

Intro to Linux

Unix and Linux operating systems
Introduction to Bash shell

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COURSE INTRODUCTION

Course website: https://cs.washington.edu/391
Learning Objectives: A collection of tools and topics not addressed in other classes that all CSE majors should know
Credit/No Credit class, assessed on weekly homework assignments
Textbook - Linux Pocket Guide

Optional, but we can only recommend it

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ASSESSMENT

Homework Assignments

There will be 10 assignments, each worth 2 points
Released after lecture, due the following Tuesday at 1:00pm
1 point for a reasonable attempt on most questions*
2 points for attempting all questions and most are correct*
* For most assignments this is graded by the autograder, and you will receive your score immediately after submission
No late assignments accepted
Collaboration is encouraged, but all submitted work must be your own.

Passing the Class

Of the 20 possible points, you need 14 to pass the class
You may earn one extra point by doing the intro survey!
Recommend doing early assignments! Assignments build off concepts from earlier topics

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DISCUSSION BOARD

Outside of office hours, the best way for you to get help with the class is to post on the course discussion board - Ed

You are encouraged to help other students by pitching into the discussion on their questions!

For personal questions, you can post privately on the Ed discussion board. Otherwise, all questions should be posted to Ed. You may post anonymously to your classmates if you prefer!

If you’re facing a serious personal situation, you can always email Hunter directly.

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COURSE STAFF

Email: hschafer@cs.washington.edu
OH:

Mon: 2:00 - 4:00, CSE 530 and Zoom

Instructor: Hunter Schafer

Email: evanhao@cs.washington.edu
OH:

Mon: 12:00 - 2:00, CSE 5th floor breakout and Zoom

TA: Evan Hao

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CLASS STRUCTURE

Lecture content will be pre-recorded and hosted on a tool called ItemPool.

No account needed to use it!
All the course content is on these videos you can watch at your own pace.
Test your understanding questions to help you learn.
Note: Recorded in a previous quarter, ignore “administrative” details (e.g., due dates) in videos. All correct dates will be shared over EdStem/course website.

Class Sessions

Hunter will host Q&A sessions during the scheduled lecture time. Encouraged to come prepared after watching the pre-recorded lectures to discuss concepts as a class.

Access:

Lessons on ItemPool will be linked on the course calendar.
Class sessions will also be recorded and can be found in the Panopto tab, but those are going to be less useful unless you are there live.
You can attend Office hours in-person or remotely.

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How many points are necessary to earn credit for this course? Enter a number.

14 (out of 20 possible)

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ACCESSING LINUX/UNIX

In a roughly suggested order

ssh into attu (CSE Majors), linuxNN (EE majors), or ovid (all UW students)
Use the Virtual Machine (VM) provided by the CS Department (for all students in 391)

For detailed information, see the Working-At-Home tab on the course website.

There are so many options available out there since Linux is all over the place! However, we do not guarantee any support for using Linux outside of these provided options.

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COURSE TOPICS

Linux command line interface (CLI)
Shell commands, input/output redirection
Version control using git
Users, groups, and permissions
Regular expressions, sed
Basic data processing
Shell scripting
Industry applications of Linux (TBD)

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A BRIEF HISTORY OF LINUX AND UNIX

Unix

First developed in 1969 at Bell Labs by Dennis Ritchie and Ken Thompson
Many key ideas still used today

“Everything is a file”
Multiple users, hierarchical file system
“Glueing” together lots of smaller files
Documentation included

macOS is a unix operating system in disguise!

Linux

Developed in 1992 by Linus Torvalds, who also developed git!

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THE SHELL

Shell: an interactive program that allows the user to interact with the operating system and its applications
Why use a shell vs. the GUI (Graphical User Interface)?

Many complicated tasks are easier to do on the command line
Useful for working on remote servers
Programmable
Customizable

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BASIC SHELL COMMANDS

command	description
pwd	Print current working directory
cd	Change working directory
ls	List files in working directory
man	Bring up manual for a command
exit	Log out of shell

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SYSTEM COMMANDS

command	description
clear	Clears all output from console
date	Output the system date
cal	Output a text calendar
uname	Print information about the current system

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RELATIVE DIRECTORIES

directory	description
.	References the working directory
..	References the parent of working directory
~username	username’s home directory
~/Desktop	Your desktop

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UNIX FILE SYSTEM

directory	description
/	Root directory that contains all directories
/bin	Applications/programs (i.e. binaries)
/dev	Hardware devices
/etc	Configuration files
/home	Contains user’s home directories
/proc	Running programs (processes)
/tmp, /var	Temporary files
/usr	Universal system resources

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DIRECTORY COMMANDS

directory	description
ls	List files in working directory
pwd	Print current working directory
cd	Change working directory
mkdir	Make a new directory
rmdir	Remove the given directory (must be empty)

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COMMAND LINE ARGUMENTS

There aren’t any consistent definitions when it comes to command line arguments, but for this class we will use the following way to describe the anatomy of a command

$ ls -al dir1

Command

Flags

Arguments

(Parameters)

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Assume you are currently in the lecture1 directory. How could you list all of the files in dir1 (including hidden files) such that you get all of the long-form information in human-readable format.

Hint: Check the man pages to see what human-readable might mean!

ls -lah dir1

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COMMAND LINE ARGUMENTS

Much like methods in Java take arguments, so do commands on the command line
Flags are modifiers which change a programs behavior slightly, and they are usually prepended with a -
For example, to list all files in long-list format, run the following

$ ls -l

Flags can be combined, to list all files in long-list format and list hidden files

$ ls -la

Commands also take arguments, such as file names
To view all files , in long-listing format, inside of dir1

$ ls -l dir1

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FILE COMMANDS

Warning: The above commands do not ask for confirmation. Be careful moving or copying files, as you might overwrite existing files!
Check the man pages for flags to prevent this behavior

directory	description
cp	Copy a file
mv	Move a file (also used to rename files)
rm	Remove the given file
touch	Create empty file, or change time-modified

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TEXT EDITORS

In many instances, you will be interacting with a Linux system with a graphical environment so a command-line text-editor is necessary
vim/emacs are powerful text-editors preferred by many experienced Linux users. It’s up to you which one to focus on in this class.

command	description
nano	Very simple editor
vim	More advanced text-editor
emacs	More advanced text-editor

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VIM BASICS

Key stroke	description
:w	Write (save) the current file
:wq	Write (save) the current file and exit
:q!	Quit, ignoring all changes
i	Go into insert mode
Esc	Go back to normal mode
hjkl	Move cursor left, down, up, right
u	Undo last change
x	Delete character

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EMACS BASICS

C = control key

M = alt/meta key

Key stroke	description
C-x C-f	Read a file into emacs
C-x C-s	Save a file to disk
C-x C-c	Exit emacs
C-s	Search forward
C-r	Search backwards
C-v	Scroll to next screen
M-v	Scroll to previous screen
C-x u	Undu

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Can a program write code?

We need YOU!

Assists you in Bash programming tasks
Translates English to Bash
Helps you to learn by example

Reasons to join

Exposure to state-of-the-art research
We pay YOU ($15 Amazon gift card)
Your data is completely anonymous

Requirements

≥18 years old

Give executable permission for all *.sh files in dir/

find /dir/ -type f -name "*.sh" -exec chmod +x {} \;

Questions? @Thomas Schweizer on

Interested? http://bit.ly/en2bash-signup

Sign-up with this link by April 1st

Hello everyone, I’m Thomas, I’m a grad student in the Programming Languages and Software Engineering group working with professors Rene Just and Mike Ernst.

We are recruiting participants for our study where we are evaluating if a translation assistant can help programmers to write Bash scripts using English descriptions.

The motivation is that sometimes you need to write a program like the example in the slide where you want to give the executable permission for all shell scripts in a certain directory. Even if it’s pretty clear in your mind what you want to do, you don’t necessarily know how to write it in the programming language or know every detail, like syntax, to get there.

Finding this information is often quite tedious and prone to errors. This is when a translation assistant can be useful by solving this task for you, which enables you to focus on the important stuff.

We’re trying to find out if computers, neural networks in this case, can write programs that are practically helpful to you. To do so, we need your help evaluating if translation assistants can help developers in programming tasks.

If that sounds interesting to you, please consider participating in the study, it’s a great opportunity to contribute to science and get some exposure to research in Machine Learning and Software Engineering. You will also be compensated for your participation with a 15$ Amazon gift card.

Please note that participating in this experiment is entirely voluntary. If you do decide to participate, the data is kept strictly confidential within the research team and is anonymized so there is no way to identify you personally.

To participate in the study, please sign-up with the link in the slide by the end of week. I will also be posting it in the chat right after. The study will take place later this quarter.

Feel free to contact me on Slack (@Thomas Schweizer) with any questions or concerns. I’ll be more than happy to answer them.

Thank you so much for considering to participate in the study. That would really help us and make a difference for our research. I’m looking forward to see all of you there.

Thank you Hunter for giving me the opportunity to give a brief glimpse of my research here today.

Have a great day and have a great quarter.

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COPY PASTE

Sign-up at http://bit.ly/en2bash-signup

Please answer by Apr. 1st.

If you have any question, feel free to contact me on Slack (@Thomas Schweizer) or by email (tschweiz@cs.washington.edu)

Thanks!