Monday,
August 25, 2003 |
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Book
Review |
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World Wide Web relies
heavily on Unix
Laxmi Kant Verma
UNIX,
developed by Kenneth Thompson and Dennis Ritchie in 1969 at AT&T’s
Bell Labs, is one of the most powerful, versatile, and flexible
operating system (OS). It was then revised many times and made
commercially available by Interactive Systems Corporation in1977. Its
popularity is due to many features including, portability, multi-user
environment, and real-time sharing of resources.
The book authored by
Sumitabha Das, an electronics engineer from Calcutta University, has
been divided into two parts. Part I covers the fundamental concepts of
the system useful for the beginners. The intermediate and advanced
concepts are explained in the second part. The author has covered Linux
also and has discussed a few commands that are different for Linux and
Unix.
The beginning of each
chapter describes what a reader will learn in that particular chapter
and also delves on topics of special interest. In the end of each
chapter conclusion, wrap up, and questions for revision are given.
Important note, tips and cautions are provided wherever needed.
In Part I, the concepts of
Unix Operating System, architecture, commands, utilities, file system,
filters have been discussed with examples. For text editing, Unix
provides a useful editor i.e. vi editor, which makes use of a number of
internal commands. The features of vi editor has been explained in
detail in a separate chapter. One of the most important features
available in the Unix is the shell. Shell is a command interpreter and a
programming language rolled in one. This topic has been discussed at a
number of places in the book, which includes shell process and shell
programming.
Unix provides multi-user
environment. There is a need for proper system administration to
maintain the user accounts, security, disk space management and
performing backups. These have been explained in the chapter, Essential
System Administration. Multi-user environment of this OS facilitates
the use of a few communication tools. These could be used to know what
others are doing and includes executing commands like finger, talk, mesg
and mailx.
Part II covers the
advanced concepts, X Window system, TCP/IP networking, the Internet,
system programming, advanced system administration and TCP/IP
administration.
Like Windows, this OS also
provides graphical environment called X Window system that provides
client/server-oriented base for displaying windowed graphics. Window
manager is the best example. It is an essential component that controls
the appearance of window and provides the means by which the user
interacts with them. Virtually everything that appears on the screen in
X is in a window and a window manager quite simply manages them.
A set of standard
protocols that could be used by all machines and networks to communicate
is called TCP/IP. TCP/IP is a vendor independent suite of protocols that
connects various machines in a network. It is described with the help of
four layers of the TCP/IP networking model.
Various freeware and
shareware programs available on the Net use Unix for exchange of
information. The World Wide Web is the Internet’s latest and finest
technology service. Large networks and Internet use the Domain Name
System (DNS) and details about DNS have been given using a table.
Due
to multiprogramming nature of Unix, multiple processes share a single
resource. If you have some programming experience, you can use your C
knowledge to develop programs and applications to ensure that the
resources are shared in the way they are meant to without conflict. All
aspects of systems programming have been described in the chapters on
systems programming.
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