Linux shell command Line Operations Guide

The Linux shell refers to a program that allows users to manipulate computers by typing instructions to the keyboard. The shell executes the command http://www.aliyun.com/zixun/aggregation/18678.html "> user input and displays the execution results on the monitor." The whole process of this interaction is text-based and differs from the graphical operations described in other chapters. This command-line-oriented user interface is called the CLI (command line interface). Before the advent of the graphical user interface (GUI), people used the command line interface to manipulate computers. Now, with more and more tools based on the graphical interface, a lot of work doesn't have to be done with a shell. However, professional Linux users think Shell is a very useful tool, learn Linux must learn to shell, at least to master some basic knowledge and basic commands.

Start shell

After starting the Linux desktop system, the shell has been running in the background, but it has not been shown. If you want it to be displayed, press the key combination below to:<ctrl> + <Alt> + <F2> F2 can be replaced with F3, F4, F5, F6. If you want to return to the graphical interface, press the following key combination:<ctrl> + <Alt> + <F7>

In addition, running the system terminal in a graphics desktop environment can also execute shell commands, which is equivalent to a command-line interface that switches out with a combination of keys. "System Terminal" after the start is a command-line operation window, you can zoom in at any time, close at any time, more convenient, recommended use. To start the system terminal method is: "Start" → "Application" → "attachment" → "System terminal"

As shown in Figure 9-1, the interface of the system terminal. The software allows the creation of multiple shell clients that are independent of each other and can switch between each other through labels.

Shell Command Basic rules

General format

The general format of the shell command is as follows: command name "Options" "Parameter 1" "Parameter 2" ... "Options" is a special definition of a command, starting with a minus sign (-), and multiple options can be connected with a minus sign (-), such as LS-A and ls-la. Parameters provide the information that the command runs, or the name of the file used during the execution of the command.

Use semicolons (;) can separate two commands so that you can enter multiple commands in one row. Commands are executed in the same order as they were entered.

Command completion

At any point in the Feed command, you can press the <Tab> key, and when you do so, the system will attempt to complete the command you have entered at this time. If the string you have entered is not sufficient to uniquely determine the command it should use, the system emits a warning sound. Press the <Tab> key again and the system gives a list of strings that can be used to complement it. With command completion, it makes sense to improve the use of long commands or files or folders that operate longer names.

History command

The system remembers the commands that were entered in the past, just by pressing the up and down arrows in the arrow keys, you can select the commands you have previously entered.

Online Help

The man command allows you to view online Help information for any command. It takes the command name as an argument, and the syntax format of the command is:

Man "command name"

You can also display Help for this command by giving the--HELP parameter after any command.