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)

Communicating between child and parent with shared memory

In this recipe, we'll learn how to use shared memory between two related processes—a parent and a child. Shared memory exists in various forms and can be used in different ways. In this book, we'll focus on the POSIX shared memory functions.

Shared memory in Linux can be used between related processes, as we are about to explore in this recipe, but also between unrelated processes using file descriptors to shared memory. When we use shared memory in this way, the memory is backed by a file in the /dev/shm directory. We'll look at this in the next recipe.

In this recipe, we'll be using anonymous shared memory—memory not backed by a file.

Shared memory is just what it sounds like—a piece of memory that is shared between processes.

Knowing how to use shared memory will enable you to write more advanced programs.

Getting ready

For this recipe, you'll only need the GCC...