The Korn shell, like the C and Bourne shells, is a program that interprets UNIX commands. It has many features that aren't found in other shells, including command history (the ability to recall and edit previous commands). The Korn shell is also faster; several of its features allow you to write programs that execute more quickly than their Bourne or C shell equivalents.
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 one of the worst "dark corners" of
shell programming: command-line interpretation. It does this by
introducing simple real-life examples and then adding options and
complexity in later chapters, illustrating the way real-world script
development generally proceeds. An additional (and unique)
programming aid, a Korn shell debugger (kshdb), is also included.
Learning the Korn Shell is an ideal resource for many UNIX users and
programmers, including software developers who want to
"prototype" their designs, system administrators who want to write
tools for their own use, and even novices who just want to use some
of ksh's more advanced interactive features.