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 PTY

In this recipe, we'll create a PTY using a C program. A PTY consists of two parts: a master (referred to as a pseudo-terminal master, or PTM) and a slave, or PTS. The program will create a PTY and print the path to the slave on the current terminal. We can then connect to that PTS with an application called screen and type away, and the characters will be printed to both the master and the slave. The slave is where the screen program is connected to, which is our terminal in this case. The master is usually quiet and runs in the background, but for demonstration purposes, we'll print the characters on the master as well.

Knowing how to create a PTY enables you to write your own terminal applications, such as xterm, Gnome Terminal, tmux, and so on.

Getting ready

For this recipe, you'll need the GCC compiler, the Make tool, and the screen program. Installation instructions for screen are found in the Technical requirements section of this chapter...