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 server

Unix sockets are similar to TCP/IP sockets, but they are only local and are represented by a socket file on the filesystem. But the overall functions that are used with Unix sockets are more or less the same as for TCP/IP sockets. The complete name for Unix sockets is Unix domain sockets.

Unix sockets are a common way for programs to communicate locally on a machine.

Knowing how to use Unix sockets will make it easier to write programs that need to communicate between them.

Getting ready

In this recipe, you'll only need the GCC compiler, the Make tool, and the generic Makefile.

How to do it…

In this recipe, we'll write a program that will act as a server. It will receive messages from a client and respond with "Message received" every time a message is received. It will also clean up after itself when either the server or the client exits. Let's get started:

  1. Write the following code in...