Advanced Programming in the UNIX Environment

CS631 - APUE

Course Outline

In this course, students will learn to develop complex system-level software in the C programming language while gaining an intimate understanding of the Unix operating system (and all OS that belong to this family, such as Linux, the BSDs, and even Mac OS X) and its programming environment.

Topics covered will include the user/kernel interface, fundamental concepts of Unix, user authentication, basic and advanced I/O, fileystems, signals, process relationships, and interprocess communication. Fundamental concepts of software development and maintenance on Unix systems (development and debugging tools such as "make" and "gdb") will also be covered.

Students are expected to have a good working knowledge of the C programming language, have written non-trivial programs before, and to be able to competently use a Unix system with a command-line shell interface. All coursework will be done exclusively on a Unix system from the command-line. All programming is done in C. This is not an introduction to using Unix nor to programming in C!

If you email me to waive the prerequisites, please provide information about how you meet the requirements listed above in bold. (This has the added benefit of showing that you've actually read at least this far on this page.)

Time, Date & Place:

Interactive/synchronous: Mondays, 18:30 Eastern, Gateway South 024 or online via Zoom
Online on-demand: anytime via YouTube video lectures

Instructor:

Jan Schaumann [jschauma@stevens.edu]

Office Hours: by appointment Mondays, 18:00 Eastern, Gateway South

When emailing me, please use your @stevens.edu address. I will likely not even see your email if it is sent from gmail or any other non-stevens address.

Resources:

Content and discussions:

• CS631APUE Mailinglist
  Note: all class communications happen via this mailing list.
  All registered students are subscribed to this list using their @stevens.edu address. It is critical that you read this list.
• Course Slack
• Course Videos / Youtube Channel (RSS feed)

Assignments and meta-information:

• Course Syllabus
• General Homework Guidelines
• Permitted use of (generative) AI technologies
• Source Code Style Guide (see also: Why You Shouldn't Nest Your Code)
• Recommendations To Write (Slightly More) Readable And (Thus) Robust Code
• Code Submission Checklist
• Links to OS Source Code
• Textbooks used in this class
• Systems used in this class
• Grading Policies
• Homework Assignments
• Midterm Project
• Group Project

Related links and documents:

• C99 standard
• Writing ASCII Text
• NetBSD Manual Pages
• Single UNIX Specification (POSIX)
• All Code Examples
• Raw course material on GitHub
• Using git

Tool Tips:

• ctags(1) [slides] [transcript]
• screen(1) [slides] [transcript]
• /usr/share/docs [slides] [transcript]
• sizeof != strlen [slides] [transcript] [sizeof.c] [sizeof manual page]
• Installing NetBSD/evbarm in UTM on Apple M1 [transcript]
• ed(1) is the standard text editor [transcript]

Source Code

You will be writing a lot of code in this class. You may also find the need to read a lot of code not written by you as well as the manual pages accompanying the sources.

Our primary reference platform being NetBSD, you can install the full sources into your VirtualBox or UTM VM via e.g., this script.

To browse or fetch sources for other Open Source Unix variations, please see these links:

• Debian
• FreeBSD
• GNU coreutils
• illumos (OpenSolaris derivative)
• NetBSD
• OpenBSD

Textbooks:

The textbook used in this class is:

• `` Advanced Programming in the UNIX® Environment'', Third Edition
  W. Richard Stevens, Stephen A. Rago
  ISBN: 0-321-63773-9
  Publisher: Addison Wesley Professional
  Code Examples | Safari Online version
  

The following books are recommended purely for your own personal reference. They're not used in the class as a text, but are related and very useful books to have:

• ``The C Programming Language'' -- important: make sure you get the 2nd Edition covering ANSI C.
  by Brian W. Kernighan and Dennis M. Ritchie.
  Prentice Hall, Inc., 1988.
  ISBN 0-13-110362-8 (paperback), 0-13-110370-9 (hardback).
  
• ``The Practice of Programming''
  by Brian W. Kernighan and Rob Pike.
  Addison-Wesley, Inc., 1999.
  ISBN 0-201-61586-X.
  

In addition, please consider MIT's "Missing Semester" a course pre- or co-requisite:

• MIT's Missing Semester -- video lectures

Systems Used

All software development will be done on a NetBSD system. It is your responsibility to gain access to such a system prior to the start of the class. Please see this page for more information. Here are instructions on how to install NetBSD in a VirtualBox or UTM.

All grading will be done on a NetBSD >= 9.3 system. While you may choose to develop on your own personal host, you should make sure that your code compiles and runs flawlessly on this OS version.

Grading:

• course notes, participation and checkpoints: 50 points
• 2 homework assignment, worth 25 points each
• 1 midterm project, worth 100 points
• 1 group project, worth 200 points
• 1 final assignment, worth 100 points
• no make-up assignments
• no extra credit
• no curve

• 90% - 100% of total available points => A
• 80% - 90% of total available points => B
• 70% - 80% of total available points => C
• 0 - 70% of total available points => F

Plagiarism, Cheating and other ways to get an F

Students are responsible for their own work. It is unethical (and in some cases illegal) to present as one's work the ideas, words or representations of another without the proper indication of the source. Therefore, it is the student's responsibility to give credit for any quotation, idea or data (such as statistical data or source code) borrowed from an outside source.

Failure to do so constitutes plagiarism, may imply copyright infringement and license violations and is viewed as cheating in this class.

Note: this also applies to the use of AI such as (but not limited to) e.g., ChatGPT. Please see this document for more details on the permitted use of AI in this class.

Homework Assignments:

Assignments will be posted as the semester progresses.

• HW#1: trivially copy a file
• HW#2: implement the command(3) library function

The following exercises are not graded, but are recommended to be completed before or soon after the given lecture to help you better understand the concepts dicussed.

• Lecture 01 - Generic Warmup Exercise
• Lecture 01 - Compare Code Exercise
• Lecture 02 - File Descriptor Warmup Exercise
• Lecture 02 - File Descriptor and Stdout Exercise
• Lecture 03 - Compare stat(1) Exercise
• Lecture 04 - File System Exercise: Implement the cd(1) and pwd(1) commands
• Lecture 06 - Process Execution Exercise: Inspect the call stack
• Lecture 06 - Program Startup Exercise
• Lecture 06 - Environment Exercise
• Lecture 07 - Play the Signals Game of Thrones
• Lecture 08 - Bi-directional communications using pipe(2)
• Lecture 08 - How do multiple pipe(2) readers/writers behave?
• Lecture 10 - HTTP Code Reading
• Lecture 11 - libgreet
• Lecture 12 - write a tool to encrypt/decrypt data using AES

Midterm Project:

Implement the "ls(1)" command as decribed in the manual page provided to you. See the full midterm project description for details.

Group Project:

Implement the "sws(1)" command as decribed in the manual page provided to you. See the full group project description for details.

Syllabus: