C Memory Lab

An interactive educational web application for exploring C concepts behind Operating Systems and Computer Security. Version 0.1 makes pointer operations visible, one statement at a time.

Run locally

No package installation or build step is required. From the project directory:

python3 -m http.server 8000

Open http://localhost:8000. You can also open index.html directly in a modern browser. The Python command only serves static files; the application has no backend.

Current functionality

• Responsive dark dashboard with six learning modules and clear availability labels.
• Interactive Pointers lab for int x = 10;, int *p = &x;, and *p = 20;.
• Current-statement highlighting, explanations, simulated variable values and addresses, and a visual pointer relationship.
• Next, Back, Reset, and Replay controls. Each step shows memory after its highlighted statement executes; Back reconstructs the preceding state.
• Address-of and dereference explanations, plus context for OS and security.
• Keyboard-accessible controls, visible focus indicators, a skip link, live announcements, and reduced-motion support.

Addresses are illustrative, not real runtime addresses. The spacing between addresses does not imply a portable C object size or layout. A pointer has its own address and stores the address of another object. This app does not compile or execute arbitrary C.

Planned modules

1. Arrays: contiguous storage, indexing, and pointer relationships.
2. Stack Frames: function calls, local variables, and lifetimes.
3. Heap: dynamic allocation, ownership, and freeing memory.
4. Strings & Buffers: character arrays, null termination, and boundaries.
5. Memory Bugs: out-of-bounds access, dangling pointers, use-after-free, and other common errors.

These modules are labeled “Coming later” and do not yet have interactive lessons.

Architecture

• index.html: semantic page structure and learning content.
• styles.css: responsive layout, dark theme, and component styling.
• app.js: module metadata and a small, deterministic three-step simulation.

Uses plain HTML, CSS, and JavaScript with no framework, runtime dependencies, backend, or build tooling. Google Fonts provides optional DM Sans and IBM Plex Mono; system sans-serif and monospace fallbacks work offline. Future lessons can follow the same explicit state-driven approach without introducing a general C interpreter.