Chapter7.Using the Command Line

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Chapter 7. Using the Command Line

The command line is a blank line where you type a command. No icons, no menus, no buttons. Well, not totally blank. A few characters, called the system prompt, display at the beginning of the line, followed by a blinking square, called a cursor. If you haven't worked in DOS or at the command prompt in Windows, a command-line interface (CLI) may be new territory for you.

The blinking cursor signals that the shell is waiting for you to type a command. The shell, a computer program, provides the interface between you and the part of Linux that executes the commandthe kernel. The shell provides the command line where you enter the command, accepts your input, interprets it, processes it, and executes the resulting command. Several shells are available for Linux. The default shell is called Bash. Bash stands for Bourne again shell, because Bash is a descendent of an earlier shell called the Bourne shell. Only the Bash shell is discussed in this book. You are unlikely to need to use a different shell unless you become a system administrator or an advanced programmer.

The shell communicates with the kernel, the core of Linux. All the computer magic occurs in the kernel. It's the kernel that transfers data to and from the peripherals (printer, screen, mouse), writes files to the hard disk, sends data across the network, and all the other low-level tasks that make a computer work. It is not the function of this book to explain the workings of the kernel. Perhaps some of you will delve into this magic after you learn the basics, but most of you will not.

Many Linux users can perform all their required tasks from the desktop, without using the command line. However, working directly in the shell is almost always faster. In addition, the command line provides more functionality. Some tasks that are difficult or impossible to accomplish from the desktop become simple when working in the shell. Even for parallel functions, commands often have many more options, providing more functionality than the desktop feature that performs a similar function. System administrators and programmers need to work in the shell frequently. After you become familiar with the shell, you may find it faster and easier to work in the shell for many of your tasks.

Many of the command descriptions in this chapter refer to files and directories. If you aren't familiar with these terms, they are explained in detail in Chapter 9.

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    Spring Into Linux
    Spring Into Linux
    ISBN: 0131853546
    EAN: 2147483647
    Year: 2005
    Pages: 362
    Authors: Janet Valade

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