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)

Why error handling is important in system programming

This recipe is a short introduction to what error handling is. We will also see an example of a common error: insufficient access rights. Knowing these basic skills will make you a better programmer in the long run.

Getting ready

For this recipe, you'll only need the GCC compiler, preferably installed via the meta-package or group install, as we covered in Chapter 1, Getting the Necessary Tools and Writing Our First Linux Programs. Make sure that the Makefile mentioned in the Technical requirements section is placed in the same directory as the source code for this recipe.

How to do it…

Follow these steps to explore a common error and how to handle it:

  1. First, we will write the program without any error handling (except the usual sanity checks for the arguments). Write the following program and save it as simple-touch-v1.c. The program will create an empty file that the user specifies as an argument...