The second edition introduces new features of bash 4.x, such as new redirection operators and substitution operators. You'll learn timeless command-line skills: navigating the file system, customizing your environment, chaining commands, and matching regular expressions. You'll understand the philosophy behind many command-line tools, understand the rich heritage of Unix supercomputers, and tap into the knowledge accumulated by generations of gurus who have eliminated the mouse from their toolbox. Once you get over the initial shell shock, you will realize how natural and logical this way of interacting with your computer is.