C Programming — Overview

What is C?

C is a general-purpose, procedural programming language developed by Dennis Ritchie at Bell Labs in 1972. It is the foundation of modern computing: the Linux kernel, Python interpreter, MySQL database, and most operating systems are written in C.

Why Learn C?

•Understand how computers actually work — memory, pointers, hardware interaction

•Foundation for C++, Rust, Go — all are influenced by C

•Embedded systems and IoT — microcontrollers (Arduino) use C

•GATE/Competitive exams — C is a core subject in all CS curricula

•Operating systems — understanding C is essential for kernel development

C vs C++ vs Python

Feature	C	C++	Python

|---|---|---|---|

Paradigm	Procedural	Multi-paradigm (OOP + procedural)	Multi-paradigm
Speed	Fastest	Very fast	Slower (interpreted)
Memory management	Manual (malloc/free)	Manual + RAII	Automatic (GC)
Use case	OS, embedded, systems	Games, system software, HPC	Scripting, ML, web
Learning curve	Moderate	Steep	Easy

Install a C Compiler

bash

# Ubuntu/Debian
sudo apt update && sudo apt install gcc build-essential
gcc --version

# macOS
xcode-select --install      # Installs Clang (Apple's C compiler)
gcc --version               # Points to Clang

# Windows: MinGW-w64 or WSL (Windows Subsystem for Linux)

# Verify
echo '#include<stdio.h>
int main(){printf("Hello\n");return 0;}' > test.c && gcc test.c -o test && ./test

Hello World

c

#include <stdio.h>    // Standard Input/Output header

int main() {
    // Print to stdout
    printf("Hello, World!\n");

    // Variables
    int age = 25;
    float price = 99.99;
    char initial = 'A';
    char name[] = "Alice";

    printf("Name: %s, Age: %d, Price: %.2f\n", name, age, price);

    return 0;  // 0 means success
}

bash

# Compile and run
gcc hello.c -o hello    # Compile to executable
./hello                 # Run
# With debugging:
gcc -g -Wall hello.c -o hello  # -g=debug info, -Wall=all warnings

Why C is in DevOps

•Understanding memory — helps diagnose memory leaks in any language

•Reading system source code — Linux kernel patches, libc

•Writing kernel modules — custom drivers, BPF programs

•Debugging — understanding how C programs crash helps with any language

Course Sections

•Fundamentals — syntax, data types, control flow, functions

•Intermediate — arrays, strings, pointers, structures

•Advanced — dynamic memory, file I/O, linked lists, system calls

•Labs — coding exercises with automated testing

•Interview — pointer questions, memory management, common patterns