The first thing users of the Linux operating system come face to face
with is the shell. "Shell" is the UNIX term for a user interface to the
system -- something that lets you communicate with the computer via the
keyboard and display.
Bash, the Free Software Foundation's
"Bourne Again Shell," is the default shell for Linux, the popular free
UNIX-like operating system. It's also a replacement for the standard
UNIX Bourne shell, which serves both as a user interface and as a
programming language. Like the FSF's other tools,
bash is more
than a mere replacement: it extends the Bourne shell in many ways.
Features include command line editing, key bindings, integrated
programming features, command completion, control structures
(especially the select construct, which enables you to create menus
easily), and new ways to customize your environment.
Whether you want to use
bash for its user interface or its programming features you will find
Learning the bash Shell a valuable guide. The book covers all of
bash's features, both for interactive use and programming. If you are new to shell programming,
Learning the bash Shell
provides an excellent introduction, covering everything from the most
basic to the most advanced features, like signal handling and command
line processing. If you've been writing shell scripts for years, it
offers a great way to find out what the new shell offers. The book is
full of examples of shell commands and programs that are designed to be
useful in your everyday life as a user, not just to illustrate the
feature being explained. All of these examples are freely available to
you online on the Internet.
Shell scripting skills never go out of style. It's the shell that unlocks the real potential of Unix. Shell scripting is essential for Unix users and system administrators-a way to quickly harness and customize the full power of any Unix system. With shell scripts, you can combine the fundamental Unix text and file processing commands to crunch data and automate repetitive tasks. But beneath this simple promise lies a treacherous ocean of variations in Unix commands and standards. Classic Shell Scripting is written to help you reliably navigate these tricky waters. Writing shell scripts requires more than just a knowledge of the shell language, it also requires familiarity with the individual Unix programs: why each one is there, how to use them by themselves, and in combination with the other programs. The authors are intimately familiar with the tips and tricks that can be used to create excellent scripts, as well as the traps that can make your best effort a bad shell script. With Classic Shell Scripting you'll avoid hours of wasted effort. You'll learn not only write useful shell scripts, but how to do it properly and portably. The ability to program and customize the shell quickly, reliably, and portably to get the best out of any individual system is an important skill for anyone operating and maintaining Unix or Linux systems. Classic Shell Scripting gives you everything you need to master these essential skills. 
UNIX For Dummies has been the standard for beginning UNIX
references for nearly ten years, and this latest edition continues that
tradition of success