TheLinuxGurus.org: Incredibly Simple Shell Programming

[ Thanks to David Culp
for this link. ]

All to often the main complaint I have heard from people
who have newly switched to Linux is the command line. Most complain
that Linux MUST be an inferior OS because it relies much to heavily
on the command line. You will also hear detractors of Linux say the
same thing.
They do not realize that in the command line lies
true power, only once you have mastered the art of the command
line, and the shell, can you truly begin to extract real power and
flexibility from the machine.”

“If you are not familiar with the term ‘shell’ I will explain.
The shell is your interface to the machine, it is how you interact
and communicate with Linux. In DOS this is most often called a
command interpreter, however the DOS command line and the Linux
shell are only distant third cousins at best, the Linux shell blows
away the DOS command line. In fact, the DOS command line under
todays Windows OS is pretty much unusable except for very simple
tasks (well its never been that great to begin with). Put simply,
when you type in a command the shell interprets it and spits out a
result. You can combine many of these commands into a file, called
a shell script, and execute them at once. This is called shell
programming and is a powerful feature of Linux (and all Unix’s).
You may also combine many of the commands on a single line in order
to execute multiple statements at a time, simply use plenty of ;’s
to seperate the individual commands!”

“If you are coming from MS Windows, you know there is only one
shell prompt available, and that is the DOS prompt. There are many
shells available for Linux and which one you use depends on your
personal preferences. The most common shell is use today is the
BASH shell, which stands for Bourne Again Shell and is a free
implementation of the Bourne shell.”