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 8: Creating Shared Libraries

In this chapter, we will learn what libraries are and why they are such a big part of Linux. We also learn the differences between static libraries and dynamic libraries. When we know what libraries are, we start to write our own—both static and dynamic ones. We also take a quick peek inside a dynamic library.

The use of libraries has many benefits—for example, a developer doesn't need to reinvent functions over and over again as there's often an existing function already in a library. A big advantage with dynamic libraries is that the resulting program gets much smaller in size, and the libraries are upgradable even after the program has been compiled.

In this chapter, we'll learn how to make our own libraries with useful functions and install them on the system. Knowing how to make and install libraries enables you to share your functions with others in a standardized way.

In this chapter, we'll cover...