C Programming Basics Notes for Beginners PDF

01. Systems Architecture

Virtual Memory Layout (Text, Data, BSS, Heap, Stack), 4-Stage Compilation (gcc -E, -S, -c, -o), main(int argc, char *argv[])

SVG Memory & Toolchain Diagrams, Stack vs Heap growth

02. Types & Data Representation

Primitive types, Fixed-width <stdint.h> (int8_t..uint64_t, size_t), Two's Complement, IEEE-754 Floats, const, enum, Explicit Type Casting

Limits reference table, Signed overflow UB vs Unsigned wrap

03. Operators & Bitwise

Prefix vs Postfix (++i vs i++), Short-Circuit evaluation, 4 Golden Bitmask Idioms (Set, Clear, Toggle, Check), Precedence & Associativity

Precedence hierarchy table, Bitwise binary register tracer

04. Standard I/O Operations

printf flags/width/precision/modifiers, scanf buffer mechanics & whitespace handling, fgets vs unsafe gets, snprintf, sscanf

In-memory stream parsing, Input buffer drain routines

05. Control Flow & Branching

if-else ladders, Dangling Else trap, switch-case jump tables, intentional fallthrough, <stdbool.h>

Jump table assembly mapping, Multi-condition tests

06. Iteration Architectures

Pre-test while, Post-test do-while, Multi-variable for headers, break, continue, Linux-style single-exit goto cleanup

Loop comparison matrix, Resource cleanup pattern

07. Functions & Stack Frames

Pass-by-Value vs Address Pointers, Stack Activation Records (Parameters, Return RIP, Saved RBP, Locals), Recursion & Base cases

SVG Stack Frame Layout diagram, Recursive stack growth trace

08. Scope & Storage Classes

auto, register, static local persistence vs global internal linkage, extern, const, volatile, restrict

Storage classes comparative table, MMIO register polling

09. Arrays & Matrices

1D contiguous allocation, Array decay to pointer (*(arr+i)), Bounds safety, Row-Major 2D formula Base + (r*C + c)*sz

SVG 2D Matrix Memory diagram, Subscript decay equivalence

10. Strings & Buffers

Null-terminator \0, Read-only literals (.rodata) vs mutable stack arrays, <string.h> (strlen, strncpy, strncat, strcmp, strstr)

Safe bounded copy idioms, String search offset calculation

11. Pointers Masterclass

Address-of &, Dereference *, Pointer Arithmetic scaling (sizeof(T)), Double pointers (**ptr), void*, const Pointer Matrix, Function Pointer callbacks & qsort

Pointer arithmetic SVG diagram, const pointer taxonomy

12. User-Defined Types

struct definition, direct . vs pointer ->, CPU word alignment & padding bytes, typedef, union shared memory, Bit-fields

SVG Alignment Byte map, Struct layout optimization

13. Dynamic Heap (DMA)

malloc(), calloc(), realloc(), free(), Safe reallocation pattern, Memory leak prevention, Dangling pointers, Double-free traps

DMA comparison table, Defensive heap pointer zeroing

14. File Handling & Streams

FILE* streams, fopen() modes ("rb", "wb", "r+b"), Text vs Binary I/O, fread(), fwrite(), fseek(), ftell(), perror()

Binary struct serialization & deserialization pipeline

15. The C Preprocessor

Object-like vs Function-like macros, Parentheses encapsulation rule, Stringification (#), Token pasting (##), Header guards (#ifndef), Predefined macros

Preprocessor expansion traces, Canonical header design

16. Defensive C & Debugging

Undefined Behavior (UB) matrix, <assert.h> runtime invariants, -Wall -Wextra -Wpedantic flags, AddressSanitizer & Valgrind

Diagnostic checklist, Memory corruption defense