Bourne Shell Scripting (wikibooks)

This book will cover the practical aspects of using and interacting with the Bourne Shell, the root of all shells in use in the Unix world. That includes interacting with the shell on a day-to-day basis for the purposes of operating the computer in normal tasks, as well as grouping together commands in files (scripts) which can be run over and over again. Since it's not practical to talk about the Bourne Shell in complete isolation, this will also mean some short jaunts into the wondrous world of Unix; not far, just enough to understand what is going on and be able to make full use of the shell's very wide capabilities.