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)

Chapter 9: Terminal I/O and Changing Terminal Behavior

In this chapter, we learn what a TTY (short for TeleTYpewriter) and a PTY (short for Pseudo-TeletYpewriter) are and how to get information about them. We also learn how to set their attributes. Then, we write a small program that takes input without echoing the text—perfect for a password prompt. We also write a program that checks the size of the current terminal.

A terminal can take many forms—for example, a terminal window in X (the graphical frontend); the seven terminals accessed with Ctrl + Alt + F1 through F7; an old serial terminal; a dial-up terminal; or a remote terminal such as Secure Shell (SSH).

A TTY is a hardware terminal, such as the consoles accessed with Ctrl + Alt + F1 through F7, or a serial console.

A PTY, on the other hand, is a pseudo-terminal, meaning it's emulated in software. Examples of PTYs are programs such as xterm, rxvt, Konsole, Gnome Terminal, or a terminal multiplexer...