C++ Programming

1. Introduction & Use Cases

C++ is a powerful, high-performance programming language used for system/software development and competitive programming. In Termux, C++ allows you to build lightning-fast utilities and exploit proof-of-concepts.

• System Programming: Building low-level tools that interact with the Linux kernel.
• Performance: Developing resource-intensive applications like scanners or crackers.
• Game Development: Using libraries like SDL2 or SFML (via X11).
• Cybersecurity: Writing memory-efficient exploits and security tools.

2. Basic Syntax & Variables

C++ is a statically typed, compiled language. To install the compiler in Termux, use pkg install clang.

#include <iostream>
#include <string>

int main() {
    std::string platform = "Termux Hub";
    int year = 2026;
    
    std::cout << "Welcome to " << platform << std::endl;
    std::cout << "Academy Year: " << year << std::endl;
    return 0;
}

3. Control Flow & Functions

Structured programming with loops and conditional logic in C++.

#include <iostream>

void checkPort(int port) {
    if (port == 80 || port == 443) {
        std::cout << "Port " << port << " is standard web port." << std::endl;
    } else {
        std::cout << "Port " << port << " is a custom port." << std::endl;
    }
}

int main() {
    int ports[] = {80, 8080, 443};
    for(int p : ports) {
        checkPort(p);
    }
    return 0;
}

4. Core Commands Cheat-sheet

• g++ -o output file.cpp - Compile a C++ file.
• ./output - Run the compiled binary.
• pkg install clang - Install the C++ compiler.
• std::cin >> var; - Get user input.
• std::cout << var; - Print to console.

5. Popular Libraries & Frameworks

• STL: Standard Template Library for data structures and algorithms.
• Boost: A massive set of high-quality peer-reviewed libraries.
• POCO: Powerful C++ class libraries for network-centric applications.
• OpenCV: Real-time computer vision library.
• Crow: A fast and easy-to-use micro web framework for C++.

6. Advanced Practical Example: File Reader

A C++ program that reads and displays the content of a file, simulating a basic 'cat' command.

#include <iostream>
#include <fstream>
#include <string>

int main(int argc, char* argv[]) {
    if (argc < 2) {
        std::cout << "Usage: ./reader [filename]" << std::endl;
        return 1;
    }
    
    std::ifstream file(argv[1]);
    std::string line;
    
    if (file.is_open()) {
        while (getline(file, line)) {
            std::cout << line << std::endl;
        }
        file.close();
    } else {
        std::cout << "Unable to open file" << std::endl;
    }
    
    return 0;
}