Lecture Examples

ABSTRACT

This repository is a structured journey through systems-level development in C. It spans the gap between raw hardware bits and high-level network communication, focusing on how a programmer manages memory, interacts with the Operating System, and builds robust, performance-oriented software.

1. Intro to Systems Programming

The entry point. This module establishes the basic relationship between the programmer and memory addresses.

• Core Tools: Understanding sizeof, pointer vs. value references, and the mechanics of SHA256 hashing.
• Memory Safety: Why returning pointers from the stack leads to undefined behavior.

2. Strings and Data

Understanding the binary representation of information.

• Bitwise Logic: Masking and shifting to manipulate data at the lowest level.
• Interpretation: The difference between signed/unsigned interpretation and the traps of character signedness.
• Internationalization: The variable-width mechanics of UTF-8 and Unicode.

3. Systems and Processes

The interface between your code and the Operating System kernel.

• Process Management: How the OS creates execution units via fork().
• The Shell Loop: Tokenizing user input and executing commands using the Fork-Exec-Wait pattern.
• Virtualization: The illusion of private memory via Virtual Memory and Copy-on-Write.

4. Memory Management

The deep-dive into the “Heap.” Learn how to build the memory management tools that modern languages take for granted.

• Struct Design: How padding and alignment affect memory footprint.
• Custom Allocators: Implementing malloc, free, and realloc using block metadata and coalescing logic to fight fragmentation.

5. Digital Communication

Scaling your C knowledge to talk to other computers.

• Network I/O: Sockets, reading/writing across buffers, and handling connection state.
• HTTP Protocol: Parsing request paths, managing query parameters, and serving dynamic content.

Technical Mapping Reference

Suggested Learning Path

1. The Foundations: Intro $\to$ Strings
2. The Environment: Systems & Processes
3. The Internals: Memory Management
4. The Application: Digital Communication