O'Reilly Media book: bash Pocket Reference

bash Pocket Reference:
You need to know how to work with the bash shell if you want to get to the heart of Unix systems, including Linux and Mac OS X. Now covering the most recent version of bash, this concise little book puts all of the essential information about bash at your fingertips. You'll quickly find answers to annoying questions that always come up when you're writing shell scripts -- What characters do you need to quote? How do you get variable substitution to do exactly what you want? How do you use arrays? -- and much more.