New Kornshell Command and Programming Language

This second edition of the KornShell book is the specification of the revised KornShell language and a reference handbook for ksh, the program that implements the KornShell language. The language has undergone major changes and additions since the first edition. The new features of the language have increased the scope of applications that are suitable for writing in ksh. In addition, command completion and a key binding mechanism have been added to this version of ksh. This book also contains a Tutorial that describes both of the functions of ksh: as an interactive command language, and as a programming language. It contains numerous examples illustrating the features of ksh, and many chapters have exercises. It also contains a Quick Reference summary of the KornShell language, including page references to the book. The format of this second edition is similar to that of the first edition. This makes it easy for readers familiar with the first edition to use this book. In addition to describing the new features of the language, many reader suggestions have been incorporated. This book is intended both for new users with little computer or shell experience, and for experienced computer users who are familiar with ksh and/or other shells. For new users, it has considerable tutorial material. For all users, it is a comprehensive reference handbook. What is the KornShell Language? The KornShell language was designed and developed by David G. Korn at AT&T Bell Laboratories. It is an interactive command language that provides access to the UNIX system and to many other systems, on the many different computers and workstations on which it is implemented. The KornShell language is also a complete, powerful, high-level programming language for writing applications, often more easily and quickly than with other high-level languages. This makes it especially suitable for prototyping. There are two other widely used shells, the Bourne shell developed by Steven Bourne at AT&T Bell Laboratories, and the C shell developed by Bill Joy at the University of California. ksh has the best features of both, plus many new features of its own. Thus ksh can do much to enhance your productivity and the quality of your work, both in interacting with the system, and in programming. ksh programs are easier to write, and are more concise and readable than programs written in a lower level language such as C. The new version of ksh has the functionality of other scripting languages such as awk, icon, perl, rexx, and tcl. For this and many other reasons, ksh is a much better scripting language than any of the other popular shells. The code size for ksh is larger than the Bourne shell or C shell programs. The revised version is even larger. In spite of its increased size, ksh provides better performance. You can write programs to run faster with ksh than with either the Bourne shell or the C shell, sometimes an order of magnitude faster. ksh has evolved and matured with extensive user feedback. It has been used by many thousands of people at AT&T since 1982, and at many other companies and universities. A survey conducted at one of the largest AT&T Bell Laboratories computer centers showed that 80% of their customers, both programmers and non-programmers, use ksh. ksh is compatible with the Bourne shell. Virtually all programs written for the Bourne shell run with ksh. If you are familiar with the Bourne shell, you can use ksh immediately, without retraining. The new version of ksh is compatible with earlier versions of ksh. ksh is readily available. It is sold (source and binary) by AT&T and Novell, and by other companies under license from AT&T both in the USA and abroad. It has been purchased by dozens of major corporations, and by many individuals for use on home computers. ksh is extensible. The KornShell language uses the same syntax for built-in commandBolsky, Morris is the author of 'New Kornshell Command and Programming Language', published 1995 under ISBN 9780131827004 and ISBN 0131827006.