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)

Chapter 6: Spawning Processes and Using Job Control

In this chapter, we'll learn about how processes are created on the system, which process is the very first one, and how all processes are related to each other. We'll then learn the many terms involved in processes and process management in Linux. After that, we'll learn how to fork new processes and what zombies and orphans are. At the end of this chapter, we'll learn what a daemon is and how to create one, before learning about what signals are and how to implement them.

Knowing how processes are created on the system is key to implementing good daemons, dealing with security, and creating efficient programs. It will also give you a better understanding of the overall system. In this chapter, we will cover the following recipes:

  • Exploring how processes are created
  • Using job control in Bash
  • Controlling and terminating processes using signals
  • Replacing the program in a process with execl...