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
Dedication
About Packt
Contributors
Preface
Index

What's in a URL


Uniform Resource Locators (URL), also known as web addresses, provide a convenient way to specify particular web resources. You can navigate to a URL by typing it into your web browser's address bar. Alternately, if you're browsing a web page and click on a link, that link is indicated with a URL.

Consider the http://www.example.com:80/res/page1.php?user=bob#account URL. Visually, the URL can be broken down like this:

The URL can indicate the protocol, the host, the port number, the document path, and hash. However, the host is the only required part. The other parts can be implied.

We can parse the example URL from the preceding diagram:

  • http://: The part before the first :// indicates the protocol. In this example, the protocol is http, but it could be a different protocol such as ftp:// or https://. If the protocol is omitted, the application will generally make an assumption. For example, your web browser would assume the protocol to be http.
  • www.example.com: This specifies...