C

C Programming

A modular C library: foundations through systems topics, with a separate workbook for extra drills and projects.

This book uses C17 as the default dialect. Examples prefer:

gcc -std=c17 -Wall -Wextra -Wpedantic -o prog prog.c
./prog

Clang is fine as a drop-in for learning:

clang -std=c17 -Wall -Wextra -Wpedantic -o prog prog.c

Who this is for

Path A — Beginner (language first)
Start at Module 1 and move in order through Module 5 before jumping ahead. Type every full program. Treat warnings as errors in practice (-Werror once you are comfortable). Goal: confident control flow, functions, arrays/strings, and a first honest encounter with pointers.

Path B — Systems-oriented (already know some C syntax)
Skim Module 1 for the compile/link mental model and warning flags, then prioritize Modules 6–8 (pointers, structures, file/system I/O). Use Modules 11–15 when you need sockets, embedded patterns, performance, testing, or threads. Still run Module 1’s multi-file and I/O labs if those habits are rusty.

Both paths should enable warnings early and avoid treating “it compiled” as “it is correct.” Undefined behavior is introduced early for a reason.

How to use this book

1. Read a section, then type the programs (do not only read them).
2. Compile with -std=c17 -Wall -Wextra -Wpedantic.
3. Break one thing on purpose; read the diagnostic; fix it.
4. Do the chapter exercises before moving on.
5. Use the workbook when you want more reps or a larger project—not as a substitute for chapter work.

How to compile examples

From any directory where you saved a single-file example:

gcc -std=c17 -Wall -Wextra -Wpedantic -o hello hello.c
./hello

Multi-file:

gcc -std=c17 -Wall -Wextra -Wpedantic -o app main.c util.c
# or
gcc -std=c17 -Wall -Wextra -Wpedantic -c main.c
gcc -std=c17 -Wall -Wextra -Wpedantic -c util.c
gcc -o app main.o util.o

Useful extras:

Flags	Purpose
-g -O0	Debug builds
-O2	Optimized builds
-fsanitize=address,undefined	Runtime checks (GCC/Clang, host-dependent)

Workbook demos live under content/99-workbook/examples/ (per module). Some multi-file folders include a Makefile—read it, then still know how to issue the raw gcc line yourself.

Workbook (content/99-workbook)

Area	Path	Use for
Examples	content/99-workbook/examples/0N-…/	Runnable demos aligned to modules
Exercises	content/99-workbook/exercises/0N-…/	Extra problem sets
Projects	content/99-workbook/projects/	Beginner → capstone project prompts

Suggested rhythm: finish the module chapters → attempt workbook exercises for that module → pick a project only when the drills feel mechanical.

Appendices under content/100-appendices/ hold resources, quick reference material, and solution notes.

Related books

Book	Overlap
Linux	Toolchain, make, and systems environment
Go	Contrasting memory and concurrency models
Maths	Discrete math and complexity behind algorithms chapters

Modules (15 + workbook + appendices)

1. Foundations and Environment — history and process model, toolchain, first programs, console I/O
   
2. Data Types and Variables — types, storage, conversions, operators
   
3. Control Flow — decisions, loops, non-local flow
   
4. Functions and Modularity — design, linkage, library overview
   
5. Arrays and Strings — contiguous data and text
   
6. Pointers and Memory — addresses, dynamic allocation, pitfalls
   
7. Structures and Types — struct, union, enum, simple ADTs
   
8. File I/O and System Programming — streams and system-facing I/O
   
9. Modern C Standards — C99 through C23 and modern practice
   
10. Data Structures and Algorithms — lists, trees, tables, graphs, sorting
    
11. Network Programming — sockets and protocols
    
12. Embedded Systems — constrained and hardware-oriented C
    
13. Performance Optimization — measure, then improve
    
14. Testing and Debugging — quality, debug, error handling
    
15. Advanced Topics and Capstone — concurrency, systems topics, capstone

Plus 99-workbook (examples, exercises, projects) and appendices.

Prerequisites

• Comfort using a text editor and a terminal
  
• Ability to install a C compiler (GCC, Clang, or MSVC/MinGW on Windows)
  
• No prior programming required for Path A; Path B assumes basic syntax familiarity

Getting started

1. Introduction to C — mental model and first mini-programs
   
2. Development Environment — install and verify the toolchain
   
3. Your First C Program — compile, multi-file, labs
   
4. Basic I/O — printf / scanf / fgets

Then continue through the modules in order (Path A) or jump to pointers and systems modules (Path B) once foundations are solid.