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)

Creating a static library

In Chapter 3, Diving Deep into C in Linux, we saw how to create a dynamic library and how it was linked from the current working directory. In this recipe, we'll make a static library instead.

A static library is included in the binary during compilation. The advantage is that the binary gets a bit more portable and independent. We can remove the static library after compilation, and the program will still work.

The downsides are that the binary will be slightly larger and that we can't update the library after it has been compiled into the program.

Knowing how to create static libraries will make it much easier to distribute and reuse your functions in new programs.

Getting ready

For this recipe, we'll need the GCC compiler. We will also use a tool called ar in this recipe. The ar program is almost always installed by default.

How to do it…

In this recipe, we'll make a small static library. The library will...