|
Shells and Utilities
Most UNIX
users are familiar with "the shell";
it is where you input commands
and get output on your screen. Often, the only contact users have with the shell
is logging in and immediately starting some application.
Some administrators, however, have modified the system to the point where users never even see the
shell, or in extreme cases, have eliminated the shell completely for the users.
Because the Linux GUI has become so easy to use, it is possible that you can go for
quite a long time without having to input commands at a shell prompt. If your only interaction
with the operating system is logging into the GUI and starting applications,
most of this entire site can only serve to satisfy your curiosity. Obviously, if all you ever do
is start a graphical application, then understanding about shell is not all that important. However, if you are
like most Linux users, understanding the basic workings of the shell
will do wonders to improve your ability to use the system to its fullest extent.
Up to this point, we have referred to
the shell as an abstract entity.
In fact, in most texts, it is usually referred to as simply "the shell", although there
are many different shells that you can use, and
there is always a program that must be started before you can interact
with "the shell". Each has its own
characteristics (or even quirks), but all behave in the same general fashion.
Because the basic concepts are the same, I will avoid talking about specific
shells until later.
In this chapter, we are going to cover the basic aspects of the shell.
We'll talk about how to issue commands and how the system
responds. Along with that, we'll cover how commands can be made to interact with
each other to provide you with the ability to make your own commands. We'll also
talk about the different kinds of shells, what each has to offer, and some
details of how particular shells behave.
|
Back to Top
