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)

Linking against libraries using GCC

In this recipe, we will learn how to link a program to an external library, both one that's installed system-wide and one that resides in our home directory. Before we can link to a library, however, we need to create it. This is also something that we are going to cover in this recipe. Knowing how to link against libraries will enable you to make use of a wide variety of ready-to-use functions. Instead of writing everything by yourself, you can use libraries that are already available. Often, there is no need to reinvent the wheel, thus saving you a lot of time.

Getting ready

For this recipe, you'll only need what's listed under the Technical requirements section of this chapter.

How to do it…

Here, we will learn how to link against both a shared library installed on your system and a library from your home directory. We will begin with a library already on your system: the math library.

Linking against the math...