Source: C Systems Lab Companion PDF

Repo: VHCosta/llc-companion-pdf Stack: Typst Author: VH Costa Status: All 11 chapters + appendices A–C complete; Gumroad live; all 3 tiers uploaded

Value Proposition

Paid companion to the free web app, sold on Gumroad. Adds:

• Exercises with full annotated solutions (primary value)
• Deeper “why” explanations behind design decisions
• Real-world codebase connections (SQLite, Redis, CPython, Linux kernel)
• Debugging chapter (GDB, Valgrind, ASan/TSan workflows, core dumps)
• Interview prep mapped to chapters with model answers

Three-Tier Build System

• Base (typst compile src/main.typ) — exercises with placeholder solution boxes
• Solutions (--input solutions=true) — full annotated solutions
• Complete (--input solutions=true --input extended=true) — solutions + extended projects

Structure

src/
├── main.typ          ← entry point, tier flags, page layout
├── template/lib.typ  ← block types: chapter-intro, callout, exercise, solution, realworld
├── chapters/         ← ch01.typ – ch11.typ
└── appendix/         ← debug.typ, interview.typ, repo.typ
content/
├── SCHEMA.md         ← canonical exercise schema
└── chNN/exN_M/       ← 43 exercises (starter/, solution/, shared/, prompt.md, meta.json)
scripts/
├── validate.sh       ← compiles all solution/ trees; 43/43 PASS
└── export.sh         ← exports/public/ (stubs) or exports/paid/ (full solutions)

Note: content/ is the canonical exercise source. scripts/validate.sh replaced the old tests/ validation approach.

Chapter Status

Note: PDF chapters have their own structure independent of the web module numbering.

Chapter	PDF Title	Web Module	Status
ch01	Setup and the Compilation Model	m01-c-is-not-java (lessons 1-1, 1-2)	Written
ch02	Types, Operators, and Control Flow	m01-c-is-not-java (lesson 1-3)	Written
ch03	Pointers and the Memory Model	m02-pointers-memory-model	Written
ch04	Dynamic Memory	m03-dynamic-memory	Written
ch05	Structs, Unions, and Bit Fields	m04-structs-unions-bitfields	Written
ch06	The C Preprocessor	m05-c-preprocessor	Written
ch07	File I/O and System Calls	m06-file-io-syscalls	Written
ch08	Processes and Signals	m07-processes-signals	Written
ch09	Sockets and Networking	m08-sockets-networking	Written
ch10	Concurrency	m09-concurrency	Written
ch11	Going Below C	m10-going-below-c	Written

Status: Shipped

All publishing tasks complete as of 2026-04-11:

• Gumroad listing live at vhcosta.gumroad.com/l/c-systems-lab ($18/$28 / $38)
• All 3 PDF tiers uploaded
• VHCosta/c-systems-lab-exercises public repo live; README updated with Gumroad URL
• Appendix C URL correct in src/appendix/repo.typ

Next planned additions: Game Boy emulator ch12 (PDF-exclusive capstone) — see meta-gb-emulator.