Learning the Korn Shell

by Rosenblatt, Bill

• ISBN13: 9780596001957
• ISBN10: 0596001959
• Edition: 2nd
• Format: Paperback
• Copyright: 2002-04-01
• Publisher: Oreilly & Associates Inc

Summary

The Korn shell is an interactive command and scripting language for accessing Unixreg; 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 Shellshows 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, orksh, has the best features of both, plus many new features of its own.kshcan 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 Shellis 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.

Author Biography

Arnold Robbins, an Atlanta native, is a professional programmer and technical author. He has worked with Unix systems since 1980, when he was introduced to a PDP-11 running a version of Sixth Edition Unix. He has been a heavy AWK user since 1987, when he became involved with gawk, the GNU project's version of AWK. As a member of the POSIX 1003.2 balloting group, he helped shape the POSIX standard for AWK. He is currently the maintainer of gawk and its documentation. He is also coauthor of the sixth edition of O'Reilly's Learning the vi Editor. Since late 1997, he and his family have been living happily in Israel.

Table of Contents

Preface	p. viii
Korn Shell Basics	p. 1
What Is a Shell?	p. 2
Scope of This Book	p. 2
History of Unix Shells	p. 3
Getting the 1993 Korn Shell	p. 5
Interactive Shell Use	p. 7
Files	p. 8
Input and Output	p. 18
Background Jobs	p. 22
Special Characters and Quoting	p. 25
Command-Line Editing	p. 33
Enabling Command-Line Editing	p. 34
The History File	p. 35
Emacs Editing Mode	p. 36
Vi Editing Mode	p. 47
The hist Command	p. 60
Finger Habits	p. 63
Customizing Your Environment	p. 65
The .profile File	p. 66
Aliases	p. 68
Options	p. 71
Shell Variables	p. 73
Customization and Subprocesses	p. 86
Customization Hints	p. 90
Basic Shell Programming	p. 91
Shell Scripts and Functions	p. 91
Shell Variables	p. 99
Compound Variables	p. 105
Indirect Variable References (namerefs)	p. 107
String Operators	p. 108
Command Substitution	p. 127
Advanced Examples: pushd and popd	p. 131
Flow Control	p. 135
if/else	p. 136
for	p. 154
case	p. 160
select	p. 164
while and until	p. 167
Command-Line Options and Typed Variables	p. 172
Command-Line Options	p. 172
Numeric Variables and Arithmetic	p. 183
Arithmetic for	p. 193
Arrays	p. 194
typeset	p. 200
Input/Output and Command-Line Processing	p. 209
I/O Redirectors	p. 209
String I/O	p. 218
Command-Line Processing	p. 236
Process Handling	p. 257
Process IDs and Job Numbers	p. 258
Job Control	p. 259
Signals	p. 263
trap	p. 270
Coroutines	p. 278
Shell Subprocesses and Subshells	p. 286
Debugging Shell Programs	p. 290
Basic Debugging Aids	p. 291
A Korn Shell Debugger	p. 300
Korn Shell Administration	p. 321
Installing the Korn Shell as the Standard Shell	p. 321
Environment Customization	p. 323
Customizing the Editing Modes	p. 327
System Security Features	p. 329
Related Shells	p. 337
Reference Information	p. 366
Building ksh from Source Code	p. 386
AT&T ast Source Code License Agreement	p. 390
Index	p. 397
Table of Contents provided by Syndetics. All Rights Reserved.