Learning the Korn Shell by Bill Rosenblatt

This Nutshell Handbook(R) is a thorough introduction to the Korn shell, both as a user interface and as a programming language. The Korn shell is a program that interprets UNIX commands. It has many features that aren't found in other shells, including command history. This book provides a clear and concise explanation of the Korn shell's features. It explains ksh string operations, co-processes, signals and signal handling, and command-line interpretation. The book also includes real-life programming examples and a Korn shell debugger called kshdb, the only known implementation of a shell debugger anywhere.