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)

Installing GDB and Valgrind

GDB and Valgrind are two useful debugging tools that we'll use later on in this book.

GDB is the GNU debugger, a tool that we can use to step through a program and see what's happening inside it. We can watch over variables, see how they change during runtime, set breakpoints where we want the program to pause, and even change variables. Bugs are inevitable, but with GDB, we can find these bugs.

Valgrind is also a tool we can use to find bugs, though it was made explicitly for finding memory leaks. Memory leaks can be challenging to find without a program such as Valgrind. Your program might work as expected for weeks, but then suddenly, things may start to go wrong. That's probably a memory leak.

Knowing how to use these tools will make you a better developer and your programs more secure.

Getting ready

Since we will be installing software here as well, we'll need to execute these commands with root privileges. If our...