Book Image

Hands-On Network Programming with C

By : Lewis Van Winkle
Book Image

Hands-On Network Programming with C

By: Lewis Van Winkle

Overview of this book

Network programming enables processes to communicate with each other over a computer network, but it is a complex task that requires programming with multiple libraries and protocols. With its support for third-party libraries and structured documentation, C is an ideal language to write network programs. Complete with step-by-step explanations of essential concepts and practical examples, this C network programming book begins with the fundamentals of Internet Protocol, TCP, and UDP. You’ll explore client-server and peer-to-peer models for information sharing and connectivity with remote computers. The book will also cover HTTP and HTTPS for communicating between your browser and website, and delve into hostname resolution with DNS, which is crucial to the functioning of the modern web. As you advance, you’ll gain insights into asynchronous socket programming and streams, and explore debugging and error handling. Finally, you’ll study network monitoring and implement security best practices. By the end of this book, you’ll have experience of working with client-server applications and be able to implement new network programs in C. The code in this book is compatible with the older C99 version as well as the latest C18 and C++17 standards. You’ll work with robust, reliable, and secure code that is portable across operating systems, including Winsock sockets for Windows and POSIX sockets for Linux and macOS.
Table of Contents (26 chapters)
Title Page
About Packt


libssh is a widely used open source C library implementing the SSH protocol. It allows us to remotely execute commands and transfer files using the SSH protocol.

libssh is structured in a way that abstracts network connections. We won't need to bother with the low-level networking APIs we've been using so far. The libssh library handles hostname resolution and creation of the needed TCP sockets for us.

Testing out libssh

Before continuing with this chapter, it is essential that you have the libssh library installed and available. Please refer to Appendix B, Setting Up Your C Compiler on WindowsAppendix C, Setting Up Your C Compiler on Linux, and Appendix D, Setting Up Your C Compiler on macOS, for libssh installation.

Our first program using libssh is designed to ensure that it's installed correctly. This program merely prints the libssh library version. The program is as follows:


#include "chap11.h"

int main()
    printf("libssh version: %s\n", ssh_version(0))...