Learning the Korn Shell

Reviewed by: Jim Huddle CNE CNE5 CBS MCSE ES-RC, send e-mail Published by: O'Reilly & Associates, Inc., go to the web site Requires: Casual Unix users MSRP: $34.95 While kids, newbies and “Windows only” users may not know it, there's a world of power available at the lowly command prompt. One of the most powerful command line interfaces is the Korn Shell. In “Learning the Korn Shell” the authors have attempted to present Korn's power and flexibility in a manner that even the most die hard GUI user should find compelling. The authors don't spend much time with fluff either. The book weighs in at 412 numbered pages, with 336 of them being direct explanation and samples of shell use. The reading is easy for those new to a command line shell, while not being condescending. Experienced Unix shell users will find it an excellent resource for creating sophisticated scripts.

The first three chapters cover the basics and Unix shell history. They include information on Unix file systems, how input and output (I/O) works in Unix, command line editing and customizing the Unix environment.

Chapters four through nine cover programming with the shell. I mean just the shell - not perl, not php, not python, just the Korn shell itself. It's amazing what a user can do with no more than the command line and scripts.

The last chapter is mainly for Unix administrators. It details how to set up the Korn shell as the default shell along with customizing the environment and editing modes. There's also about seven and a half pages on making shell scripts more secure.kickstartnews.com is an online web publication and newsletter

If you are used to using one of the other myriad shells available for Unix/Linux then you will want to read Appendix A. It compares features of the major shells with Korn and references chapters in the book to illustrate Korn's differences.

If your flavor of Unix doesn't come with the Korn shell, Appendix C shows you how to get it. There are URLs showing where to go and a table showing what types are supported. Linux is there of course, along with versions for Solaris, MVS, AIX and even Unixware.

The back of the book contains a removable quick reference. It contains a good listing of the shell's control commands, built in variables, expressions and commands.

This is a must read for folks using Unix/Linux. Even if you can never imagine yourself using the command line, you will find that the power inherent in the Korn shell will allow you to do things the GUIs either can't do at all, or at best only manage with lesser functionality.

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