Day 19: The Mask
Section 2.7, bitwise operators, and why the same 8 bits mean different things depending on who's reading them.
Posts
Day 18: Why 'A' Is Not A Character
Closed the overnight question on why character constants are int, worked through sections 2.3 through 2.5, and wrote exercise 2-2 — the one where short-circuit evaluation turns out to be a security guarantee.
Day 17: The Break Day That Wasn't
Took a day off from K&R and spent it getting a dead 3D printing lab alive. Turns out debugging firmware and tracing undocumented wiring is just hacking with different stakes.
Day 016 The Type System Bites
Chapter 2 opens and the type system immediately starts lying to you.
Day 015 The Chapter 1 Test
Testing everything from Chapter 1. Feynman gauntlet, code tracing, security connections, and closing gaps I did not know I had.
Day 014 The Parser's Dilemma
Finishing Chapter 1 with the two hardest exercises. Comment stripping, bracket matching, and why parsers that don't understand context create entire vulnerability classes.
Day 013 Lucky Number
K&R exercises 1-20 through 1-22. Tab expansion, tab compression, line folding. A bug that hid in plain sight.
Day 012 Two Counters
Exercises 1-16 through 1-18. Dual counters, GDB investigations, and what happens when zero means two things.
Day 011: The Quiet Byte
K&R 1.8 and 1.9. Call by value, character arrays, and the single byte that holds all of C together.
Day 010: The Memory Next Door
K&R 1.6 and 1.7. Arrays, character arithmetic, functions. And the first time I watched a bug disappear into memory that wasn't mine.
Day 009: Shortcut Tax Repaid
Rebuilding ten exercises from scratch on a different machine. No peeking. No shortcuts. Proof of ownership.
Day 008: Consistency
Day 007.5: The Exploit Lab
Day 007 Earning It Clean
Rebuilding exercise 1-10 from scratch, word counting with state machines, and threat modeling a 20-line program.
Day 006 The Shortcut Tax
Line counting, state tracking, and the cost of reaching for someone else's answer.
Day 005 The Program Listens
C stops printing and starts listening. getchar, putchar, and the precedence trap that has ruined code for fifty years.
Day 004 What They Didn't Know
K&R section 1.4. Symbolic constants. The preprocessor. And the realization that every layer was built by people who could not see what was coming.
Day 003 The For Statement
Day 002 the Type System
Day 001 the Foundation
Starting Point
First post. What this is about.