IN THIS CHAPTER
Understanding the Linux shell
Using the Linux shell
Working with the Linux file system
Using the vi text editor in Linux
Before icons and windows took over computer screens, you typed commands to interact with most computers. On UNIX systems, from which Linux was derived, the program used to interpret and manage commands was referred to as the shell.
No matter which Linux distribution you are using, you can always count on one thing being available to you: the shell. It provides a way to create executable script files, run programs, work with file systems, compile computer code, operate a system, and manage the computer. Although the shell is less intuitive than common graphic user interfaces (GUIs), most Linux experts consider the shell to be much more powerful than GUIs. Shells have been around a long time, and many advanced features have been built into them.
The Linux shell illustrated in this chapter is called the bash shell, which stands for Bourne Again Shell. The name is derived from the fact that bash is compatible with the first UNIX shell: the Bourne shell (named after its creator, and represented by the
sh command). While bash is included with most distributions, and considered a standard, other shells are available. Other popular shells include the C shell (csh), which is popular among BSD UNIX users, and the Korn shell (ksh), which is popular among UNIX System V users. Linux also has a tcsh shell (a C shell look-alike) ...