Low-Level Programming Guide

This repository is a learning guide for low-level programming concepts, with an emphasis on C and the underlying computer systems that make code work.

What this repository is

• A theory-driven curriculum for beginners and intermediate learners.
• A collection of lessons explaining how code, memory, pointers, data, and system calls work at a low level.
• A reference for developers who want to understand C programming without relying on high-level libraries.

What you will learn

• Fundamental computer concepts and how programs are built.
• Data representation in binary, characters, strings, arrays, and types.
• Pointer operations, pointer arithmetic, and pointer-related pitfalls.
• Function definitions, arguments, return values, and execution flow.
• Memory management: stack, heap, allocation, reallocation, and freeing memory.
• OS interaction through system calls, file descriptors, and standard I/O using low-level interfaces.
• Core math and algorithm topics, including arithmetic, Fibonacci, primes, square root, N-Queens, and bitwise operations.

Repository structure

• theory/ - main content folder.
• theory/01-fundamentals/ - basic computer, compilation, and toolchain concepts.
• theory/02-data/ - data types, characters, strings, and arrays.
• theory/03-pointers/ - pointer usage, pointer arithmetic, and behavior.
• theory/04-functions/ - functions, parameters, return values, and function pointers.
• theory/05-memory-management/ - malloc, calloc, realloc, free, and memory layout.
• theory/06-systems/ - system headers, file descriptors, standard I/O, and system calls.
• theory/07-math/ - algorithms, arithmetic, and bitwise programming examples.

How to use it

1. Start in theory/README.md to see the category overview.
2. Open a numbered topic folder like theory/01-fundamentals/.
3. Read the LESSON.md file for detailed theory.
4. Use CHEATSHEET.md for quick reference.
5. Review EXAMPLE.md for practical examples and code snippets.

Notes

• All C examples are designed to use low-level I/O and system-level behavior, avoiding stdio.h and printf() where possible.
• This repo is for learning how C programs behave at a lower layer, including memory and OS interactions.