Book Image

Hands-On System Programming with C++

By : Dr. Rian Quinn
Book Image

Hands-On System Programming with C++

By: Dr. Rian Quinn

Overview of this book

C++ is a general-purpose programming language with a bias toward system programming as it provides ready access to hardware-level resources, efficient compilation, and a versatile approach to higher-level abstractions. This book will help you understand the benefits of system programming with C++17. You will gain a firm understanding of various C, C++, and POSIX standards, as well as their respective system types for both C++ and POSIX. After a brief refresher on C++, Resource Acquisition Is Initialization (RAII), and the new C++ Guideline Support Library (GSL), you will learn to program Linux and Unix systems along with process management. As you progress through the chapters, you will become acquainted with C++'s support for IO. You will then study various memory management methods, including a chapter on allocators and how they benefit system programming. You will also explore how to program file input and output and learn about POSIX sockets. This book will help you get to grips with safely setting up a UDP and TCP server/client. Finally, you will be guided through Unix time interfaces, multithreading, and error handling with C++ exceptions. By the end of this book, you will be comfortable with using C++ to program high-quality systems.
Table of Contents (16 chapters)

Trying out an example for processing packets

In this example, we will discuss how to process the following packet from the client to the server:

struct packet
{
uint64_t len;
char buf[MAX_SIZE];

uint64_t data1;
uint64_t data2;
};

The packet consists of some fixed-width integer data and a string (fields in a network must always be fixed width, as you might not have control of the type of computer your application is running on and non-fixed width types, such as int and long, might change depending on the computer).

This type of packet is common among many programs, but as will be demonstrated, this type of packet has challenges with respect to safely parsing.

The server is identical to the previous TCP examples, minus the recv_packet() function (and the recv() function processes packets instead of std::arrays):

class myserver
{
...

void recv_packet()
{
if...