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)

Using job control in Bash

Not only will job control give you a better understanding of foreground and background processes, but it will also make you more efficient when working on a terminal. Being able to put a process in the background frees up your terminal to do other tasks.

Getting ready

Nothing particular is required for this recipe, except for the Bash shell. Bash is most often the default shell, so it's likely that you already have it installed.

How to do it…

In this recipe, we will start and stop several processes, send them to the background, and bring them back to the foreground. This will give us an understanding of background and foreground processes. Let's get started:

  1. Previously, we have seen how to start a process in the background with an ampersand (&). We will repeat that here, but we will also list the current jobs running and bring one of them to the foreground. The first background process we'll start here is sleep...