Linux operating system and command knowledge Rollup _linux

What is an operating system? This question is very simple! The software that manages the computer's hardware and software is the operating system. The operating system is the interface between the user and the computer, as well as the computer hardware and other software. Operating system functions include the management of computer system hardware, software and data resources, control program operation, improve the Man-machine interface, to provide support for other applications, so that all resources of the computer system to maximize the role of providing various forms of user interface, so that users have a good working environment, Provide the necessary service and the corresponding interface for other software development. In fact, the user is not exposed to the operating system, the operating system manages the computer hardware resources, at the same time, according to the application resource requests, allocation of resources, such as: dividing the CPU time, the opening of memory space, call printers and so on. So what is the structure of the operating system? Here I give you a picture to make an understanding.

From the above we can clearly see in our hardware based on the kernel, the core is shell, did not see the operating system we said. In fact, the kernel plus shell is the operating system, it can be said that the operating system has the kernel and shell composition.
What does the kernel do? The kernel is responsible for abstracting our computer hardware and then servicing the top application through system calls and library files.

The shell is our interactive window. Just like our Microsoft System has a desktop, we can know how to operate. The shell is the same as the desktop, except that he is a command-line mode rather than a graphics mode.

The application is that we install the service, like we use QQ is an application, but the application on the server is a service, because he wants to provide services to other computers. It must be easy for everyone to understand that. C_0016.gif
We must keep in mind the above figure, why? Because he is we engaged in the operation of the work of a large sum! If we want to play Linux well, we must know what we do and what we do. Now that we understand the architecture of the operating system. Next we'll look at the Linux operating system. In the front we have a simple knowledge of the Linux operating system and his Origin and branch development. We choose CentOS operating system Today, why choose CentOS? Because now the market he is Big Brother mainstream. His advantage is that it is not only open source, stable and free, so it is used by many enterprises. We have learned Linux, the other version is the same, there is a slight change, so people do not worry.

The structure and installation of Linux operating system we will, and then we will learn how to play the Linux operating system. To play a good Linux operating system, we must be very familiar with the command, Linux commands about thousands of, but we only have more than 100 to use enough. So don't worry, first make an understanding of the command structure as shown below

Note that Linux commands are strictly case-sensitive

Below I will do a simple classification of this more than 100 commands: File directory class, view class, Lookup class, help class, System Information class, user class, disk class, network class, Process class, installation class, time class, Timer task class, file operation Class A total of 13 categories. Note that the following is a brief introduction to the command, which we will discuss in detail about which command to use.

This chapter is first introduced here, the next section, based on the above command classification to do a detailed introduction. Children's shoes may feel how I give other ways to tell different, a lot of teaching is the first scattered introduction command, and finally let you summarize. Here I say why I write, command this thing is I learn Linux the biggest obstacle, he is very difficult to remember, I learn when the inductive classification, and then the way of rote, to the final collapse. The so-called understanding of memory is difficult. Here I help you summed up the good, children's shoes as long as the effort to remember them, you learn Linux is very easy! We begin to master these commands first. I'll add some later. Everyone must take notes well!