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)

Error handling POSIX-style

POSIX-style error handling provides the most basic form of error handling possible, capable of being leveraged on almost any system, in almost any program. Written with standard C in mind, POSIX-style error handling takes the following form:

if (foo() != 0) {
std::cout << errno << '\n';

Generally, each function called either returns 0 on success or -1 on failure, and stores the error code into a global (non-thread safe) implementation-defined macro, called errno. The reason 0 is used for success is that on most CPUs, comparing a variable to 0 is faster than comparing a variable to any other value, and the success case is the expected case. The following example demonstrates how this pattern is used:

#include <cstring>
#include <iostream>

int myfunc(int val)
if (val == 42) {
errno = EINVAL;