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)

Handling some common errors

In this recipe, we will look at some common errors we can handle. Knowing what errors to look for is step one of mastering error handling. A police officer can't catch the bad guys if they don't know which crimes to look for.

We will look at both errors that can occur due to resource limitations on a computer, permission errors, and mathematical errors. It's important to remember, though, that most functions return a special value (often -1 or some predefined value) when errors occur. The actual data is returned when no errors occur.

We will also briefly touch on the subject of handling buffer overflows. Buffer overflows are a vast subject that deserves a book of its own, but some short examples can help.

Getting ready

In this recipe, we'll write shorter code samples and compile them with GCC and Make. We'll also read some man pages from the POSIX Programmer's Manual. If you are using Debian or Ubuntu, you have to...