While the bash shell includes a large number of commands, the details of the bash shell are fairly straightforward. Interactivity makes it easy to recall previous commands. Command completion allows you to find the command that you need with just a couple of strokes of the Tab key.
Shell and environment variables are maintained in some basic configuration files in the /etc and individual users home directories. These variables determine the basic setup of the command-line interface. Other variables determine the size of your history, the default terminal, standard e-mail directories, and more.
There are a number of secrets associated with the shell. They include the three basic data streams: standard input, standard output, and standard error. Also, you can run commands in the background. Special shell characters set terminal parameters and allow you to use the Ctrl key to do different things on your keyboard. The tilde ( ~ ) represents any user s home directory.
Dots and double dots can help you navigate through the Linux filesystem hierarchy. Wildcards help you identify files and commands even when you don t know the complete name . While forward slashes help you navigate directories, backslashes escape the meaning of characters such as asterisks and spaces. Single, double, and back quotes let you process variables and commands in different ways. Aliases make it possible to rename commands that you might otherwise forget.
That completes Part II, where we have examined the fundamentals of Linux. In Part III, we ll look at a number of basic administrative functions. Chapter 09 begins this process by looking at how you administer users and groups. Red Hat Linux promotes security by helping you administer users and groups with the Shadow Password Suite, quotas, and the User Private Group scheme.