Bash Pocket Reference. Arnold Robbins

This pocket reference covers Bash, particularly version 4.1, the primary shell for GNU/Linux and Mac OS X. Bash is available for Solaris and the various BSD systems, and can be easily compiled for just about any other Unix system. The following topics are covered:
History
Overview of features
Invoking the shell
Syntax
Functions
Variables
Arithmetic expressions
Command history
Programmable completion
Job control
Shell options
Command execution
Coprocesses
Restricted shells
Built-in commands
Resources