Book Image

Linux System Programming Techniques

By : Jack-Benny Persson
Book Image

Linux System Programming Techniques

By: Jack-Benny Persson

Overview of this book

Linux is the world's most popular open source operating system (OS). Linux System Programming Techniques will enable you to extend the Linux OS with your own system programs and communicate with other programs on the system. The book begins by exploring the Linux filesystem, its basic commands, built-in manual pages, the GNU compiler collection (GCC), and Linux system calls. You'll then discover how to handle errors in your programs and will learn to catch errors and print relevant information about them. The book takes you through multiple recipes on how to read and write files on the system, using both streams and file descriptors. As you advance, you'll delve into forking, creating zombie processes, and daemons, along with recipes on how to handle daemons using systemd. After this, you'll find out how to create shared libraries and start exploring different types of interprocess communication (IPC). In the later chapters, recipes on how to write programs using POSIX threads and how to debug your programs using the GNU debugger (GDB) and Valgrind will also be covered. By the end of this Linux book, you will be able to develop your own system programs for Linux, including daemons, tools, clients, and filters.
Table of Contents (14 chapters)

Unix socket – creating the client

In the previous recipe, we created a Unix domain socket server. In this recipe, we'll create a client for that socket and then communicate between the client and the server.

In this recipe, we'll see how we can use the socket to communicate between a server and a client. Knowing how to communicate over a socket is essential to using sockets.

Getting ready

Before doing this recipe, you should have finished the previous recipe; otherwise, you won't have a server to talk to.

You'll also need the GCC compiler, the Make tool, and the generic Makefile for this recipe.

How to do it…

In this recipe, we'll write a client for the server that we wrote in the previous recipe. Once they are connected, the client can send messages to the server, and the server will respond with Message received. Let's get started:

  1. Write the following code in a file and save it as unix-client.c. Since this code...