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)

Searching the manual for information

If we don't know the exact name of a particular command, function, or system call, we can search all the manuals in the system for the correct one. In this recipe, we will learn how to use the apropos command to search the manual pages.

Getting ready

The same requirements apply here that applied for the previous recipe.

How to do it…

Let's search the manual for different words, narrowing our result for each step:

  1. Type in apropos directory. A long list of manual pages will present itself. After each manual, there is a number inside parentheses. This number is the section that the manual page is located in.
  2. To narrow the search down to only section 3 (library calls), type in apropos -s 3 directory.
  3. Let's narrow down the search ever further. Type in apropos -s 3 -a remove directory. The -a option stands for and.

How it works…

The apropos command searches the manual pages descriptions...