This chapter presents a view of Linux from the shell. The shell is a command-line interpreter that lets you access some of the most critical Linux tools. The shell is powerful, complex, and almost completely unintuitive.
Although at first it isn't obvious how to use the shell, with the right help you can quickly learn many of the most important shell features. In CentOS,
bash is the shell command interpreter used by default, and therefore, the one used for most of the examples in this chapter. Other shells, such as
csh, ksh, sh, and others, are also available and are therefore also noted in this chapter.
This chapter is your guide to working with the Linux system commands, processes, and file system from the shell. It describes the shell environment and helps you tailor it to your needs. It also describes how to use and move around the file system.
Throughout this book, there are procedures that require you to use a shell to run commands. How you first get to a shell depends on whether your computer is configured to have a graphical user interface (GUI) or not. A desktop system, by its nature, starts with a GUI. Server systems often are run entirely from the command line. Here are ways of reaching a shell, depending on whether you have a desktop GUI running or not:
No Desktop—If your Linux system has no GUI (or one ...