The Bourne Again Shell is based on the Bourne Shell (an early UNIX shell that this book refers to as the original Bourne Shell to avoid confusion), which was written by Steve Bourne of AT&T's Bell Laboratories. Over the years the original Bourne Shell has been expanded and is still the basic shell provided with many commercial versions of UNIX.
tip || Shell Programming
Because many users prefer the Bourne Again Shells programming language to that of the TC Shell and because it shares many common features with the Z Shell programming language, this and the following chapter describe bash (and zsh) programming in detail.
Because of its long and successful history, the Bourne Shell has been used to write many of the shell scripts that ...