Chapter 1: Background


Overview

The UNIX computer operating system has had a fascinating history and evolution. Starting as a research project begun by a handful of people, it has become an important product used extensively in business, academia, and government. Today, people use operating systems with many different names that are variants of UNIX. Many of the commands and utilities in these different variants are identical and others are extremely similar. The differences between these variants often lie in the inner workings of the operating system, not seen by the user, as well as in special added capabilities for advanced users or system administrations.

This chapter provides a foundation for understanding what UNIX is and how it has evolved. It describes the structure of UNIX and introduces its major components, including the shell, the file system, and the kernel. You will see how the applications and commands you use relate to this structure. Understanding the relationships among these components will help you read the rest of this book and use any version of UNIX effectively.

To gain an insight into how the relationships between the different components of UNIX evolved, you should learn something about the history of UNIX from its birth at Bell Laboratories to the early twenty-first century Understanding this history will also help you understand the origins of different UNIX variants and help you see how they are related. The chapter also describes the standards that have been developed and are now used as the yardstick for determining whether an operating system can be called “UNIX.”

This chapter also includes a description of the most widely used UNIX variants. In particular, you will read about the history and philosophy of Linux, an open-source version of UNIX that has become exceedingly popular. You will also learn about the most widely used UNIX variants, including Solaris, AIX, and HP-UX, as well as FreeBSD, NetBSD, OpenBSD, Mac OS X, UnixWare, and IRIX. You will also find an extensive timeline that displays how the important variants of UNIX have evolved. Important contributors to the development of UNIX are also noted.

Because UNIX variants often compete with versions of Windows NT, this chapter compares these two operating systems. The chapter concludes with a discussion of the future of UNIX and some words of advice about which UNIX version you might want to choose.




UNIX. The Complete Reference
UNIX: The Complete Reference, Second Edition (Complete Reference Series)
ISBN: 0072263369
EAN: 2147483647
Year: 2006
Pages: 316

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