Linux Yourself

Concept and Programming

Sunil K. Singh

• Publisher: Chapman and Hall/CRC
• Year: 2021
• ISBN:
  9780429820519
• Edition: 1
• Topic: Computer Science
• Subtopic: Systems Architecture
• Index: Computer Science

Numerous people still believe that learning and acquiring expertise in Linux is not easy, that only a professional can understand how a Linux system works. Nowadays, Linux has gained much popularity both at home and at the workplace. Linux Yourself: Concept and Programming aims to help and guide people of all ages by offering a deep insight into the concept of Linux, its usage, programming, administration, and several other connected topics in an easy approach. This book can also be used as a textbook for undergraduate/postgraduate engineering students and others who have a passion to gain expertise in the field of computer science/information technology as a Linux developer or administrator.

The word " Yourself " in the title refers to the fact that the content of this book is designed to give a good foundation to understand the Linux concept and to guide yourself as a good Linux professional in various platforms. There are no prerequisites to understand the contents from this book, and a person with basic knowledge of C programming language will be able to grasp the concept with ease. With this mindset, all the topics are presented in such a way that it should be simple, clear, and straightforward with many examples and figures.

Linux is distinguished by its own power and flexibility, along with open-source accessibility and community as compared to other operating systems, such as Windows and macOS. It is the author's sincere view that readers of all levels will find this book worthwhile and will be able to learn or sharpen their skills.

KEY FEATURES

• Provides a deep conceptual learning and expertise in programming skill for any user about Linux, UNIX, and their features.
• Elaborates GUI and CUI including Linux commands, various shells, and the vi editor

• 
  
  

• Details file management and file systems to understand Linux system architecture easily

• 
  
  

• Promotes hands-on practices of regular expressions and advanced filters, such as sed and awk through many helpful examples

• 
  
  

• Describes an insight view of shell scripting, process, thread, system calls, signal, inter-process communication, X Window System, and many more aspects to understand the system programming in the Linux environment

• 
  
  

• Gives a detailed description of Linux administration by elaborating LILO, GRUB, RPM-based package, and program installation and compilation that can be very helpful in managing the Linux system in a very efficient way

• 
  
  

• Reports some famous Linux distributions to understand the similarity among all popular available Linux and other features as case studies

• 
  
  

Section I

Linux Concept

1

Getting Started

Many people still believe that learning, and acquiring expertise in, Linux is an uphill task or only professionals can understand how a Linux system works. However, due to the advancements in development, Linux has gained much popularity both at home and at the workplace. This book uses an easy approach and aims to help and guide people of all age-groups to gain knowledge of Linux which is useful for all purposes. The term Linux system refers to a system which runs on a Linux-based operating system (OS). There exist a large number of flavors or distributions of Linux. Before we can explore the details of Linux, we need to explain the basic concepts of an OS and its features in subsequent sections.

1.1 Getting Started with OS

An OS is an essential part of a computer system. Sometimes, users refer to OS as the heart of the computer. An OS serves as an interface between the user and computer hardware. The job of an OS is to offer an environment in which users can execute application programs in an interactive and efficient way. An OS is also defined as a set of software that supervises computer hardware resources, offers common resources, and controls the execution of various computer programs. If a computer is in running state, then the OS is the only program that is always executing and is referred to as the kernel, while all other programs are called application programs.

Before addressing the various features and operations of Linux OS, we must explore the underlying structure of a computer system. The fundamental modules of a computer system are OS, computer hardware, application programs, and users. All such modules are arranged as shown in Figure 1.1.

FIGURE 1.1 Arrangement of fundamental modules of a computer system.

The whole computer system is broadly divided into three parts: user: end users and developers; software: application software and OS; and hardware: central processing unit (CPU), input/output (I/O) devices, and memory. According to Figure 1.1, the OS synchronizes and controls the utilization of computer hardware between the various application software packages for different users.

Further, to identify the various features of an OS, we must look at its facilities. An OS gives facilities equally to users and application programs to perform various operations such as input/output operations, program execution, file system manipulation, network communication, error detection and correction, resource distribution, safety, and security. Therefore, the size of an OS varies according to the numbers of services provided. OS’s development is split into smaller modules because of its complexity and large size. The functionality of each module should be well defined so that it can effectively coordinate with other modules.

1.2 A Brief Overview of Unix and Linux

Linux Yourself demonstrates how to build your concepts and programming skills to become an advanced Linux user or developer or both. Linux and Unix are other OSs such as Windows, DOS, and macOS. Linux, in many ways, is a clone of Unix. In recent years, Linux has become an observable fact and experience in the world of technology.

Unix is one of the most popular multitasking, secure, portable, and multiuser OSs. It was invented and developed by Ken Thompson and Dennis Ritchie at AT&T Bell Labs in the early 1970s. Initially, the basic objective was to create Unix for their personal use. Primarily, the code of Unix was written in B language and became operational on a PDP-7 in 1970. The first noteworthy achievement was changing the Unix system from the PDP-7 to the PDP-11. It gave the first intimation to everyone that Unix would act as an OS for all computer systems. In 1972, the subsequent major achievement was attained by altering (rewriting) the whole Unix programming code in C language. After converting, the C programming code of Unix confirmed the benefits of utilizing a high-level language, and presently, all Unix module implementations are written in C programming language.

Although Bell Labs was not in the computer business, even after 1974, Unix OS was first described in a technical journal. This prompted a great interest in various commercial institutions and universities. After this, Unix was distributed to commercial institutions as well as universities under AT&T (Bell Labs) licenses for their modified value-added version. After that, brilliant researchers started writing their own software and utility programs which were added to the Unix code. As a result, the most significant non-AT&T Unix system was developed at the University of California, Berkeley, known as Unix Berkeley Software Distribution (BSD). Subsequently, 1976 onward, like BSD, some other Unix flavors came into existence, such as IBM-AIX, SCO Unix, SunOS, HP-UX, FreeBSD, Linux, Mac OS X, SGI IRIX, and Sun Solaris. Unix is one of the utmost achievements in computer science, and for this supreme contribution, Dennis Ritchie and Ken Thompson received ACM Turing Award in 1983.

In 1990, 21-year-old Linus Torvalds, a computer science undergraduate, needed to purchase Unix OS for his own computer, but due to its high cost, he could not afford to buy it. Thereafter, he started writing his own Unix-like OS; later, it was announced as “Linux.” He posted the Linux on the Internet in 1991, so that anyone can use it without paying any money. Linux is a free and stable open-source OS because its source code is available publicly. The Linux kernel operates on several different platforms including Intel, IBM, and Alpha and even some handheld PDAs and others. Linux is available under the GNU General Public License (GPL) that comprises a complete set of development tools, graphical user interfaces (GUIs), hardware support, and application programs extending from office suites to multimedia applications. Linux has turned into one of the most important OSs and been operated for years on mainframes and minicomputers. The Linux OS is widely used for a broad range of systems such as personal computers (PCs), workstations, network servers, and high-performance computing systems.

Linux takes the Unix system ...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Preface
• Acknowledgments
• Author
• Section I Linux Concept
• Section II Linux Programming
• Section III Case Studies
• Index