Learning the Korn Shell

by Arnold Robbins

The Korn shell is an interactive command and scripting language for accessing Unix® and other computer systems. As a complete and high-level programming language in itself, it's been a favorite since it was developed in the mid 1980s by David G. Korn at AT&T Bell Laboratories. Knowing how to use it is an essential skill for serious Unix users. Learning the Korn Shell shows you how to use the Korn shell as a user interface and as a programming environment. Writing applications is often easier and quicker with Korn than with other high-level languages. Because of this, the Korn shell is the most often used shell in commercial environments and among inexperienced users. There are two other widely used shells, the Bourne shell and the C shell. The Korn shell, or ksh , has the best features of both, plus many new features of its own. ksh can do much to enhance productivity and the quality of a user's work, both in interacting with the system, and in programming. The new version, ksh93 , has the functionality of other scripting languages such as awk, icon, Perl, rexx, and tcl. Learning the Korn Shell is the key to gaining control of the Korn shell and becoming adept at using it as an interactive command and scripting language. Prior programming experience is not required in order to understand the chapters on basic shell programming. Readers will learn how to write many applications more easily and quickly than with other high-level languages. In addition, readers will also learn about Unix utilities and the way the Unix operating system works in general. The authors maintain that you shouldn't have to be an internals expert to use and program the shell effectively. The second edition covers all the features of the current version of the Korn shell, including many new features not in earlier versions of ksh93, making it the most up-to-date reference available on the Korn shell. It compares the current version of the Korn shell to several other Bourne-compatible shells, including several Unix emulation environments for MS-DOS and Windows. In addition, it describes how to download and build ksh93 from source code. A solid offering for many years, this newly revised title inherits a long tradition of trust among computer professionals who want to learn or refine an essential skill.

Genres: Computers, Technology, Technical, Nonfiction, Programming

396 pages, Paperback

First published January 1, 1993

Reviews

[Andy · Rating 5 out of 5]

Many happy hours being paid to write ksh programs and utilities over the years, with this trusty tome by my side to illuminate the way. If you need to write ksh you need look no further.

[Bernie4444 · Rating 5 out of 5]

Learning the Korn Shell (2nd Edition)

I once was blind. Spending decades in the UNIX world I spent time with several shells. Down through the years, I visited many shells and even bought a book on the Korn Shell by the designer David Korn. I sort of got complacent (know-it-all).

Now obtaining a position supporting AIX I once again find that the preferred supported shell is the Korn shell; even sh is linked to ksh93. Several times I came across unexplainable anomalies; sometimes paths would be absolute and at other times they would follow links. Traps seemed to work a tad differently and other outcomes seemed to be hit or miss.

The purchase of this book has been a real eye-opener. What seemed to be arbitrary was in reality lack of personal knowledge of the latest version of the Korn shell.

I could not believe that a book by David Korn of AT&T did not even mention signals.

Some of the highlights of the book are:
Job control
Functions
Command history
Command-line editing
Integrated programming features
Control structures
Debugging primitives
Regular expressions
Advanced I/O features
New options and variables
Increased speed
Security features
Major features
Security features
POSIX compliance
Arithmetic for loops
Floating-point arithmetic
Structured variable names
Indirect variable references
Associative arrays
Additional text manipulation facilities
More built-in commands

[Daniel · Rating 5 out of 5]

I have been programming Korn shell scripts for a year and decided I needed a formal training on this subject. There are many internet courses or tutorials on this topic but none of them beats the contents of this book and its very clear and precise - but not abusively long - explanations.

Authors cut to the chase, without adorning text with less objective text. It goes step by step from start to the more advanced tasks painless.

Mandatory.

[Islefaye · Rating 3 out of 5]

very helpful once upon a time