Common Linux Commands Explanation (fourth day)--bash section

When I was learning Linux, I skipped something very important. such as partitioning. There is also vim in-depth learning. Partition did not learn because I installed a virtual machine, do not know what the reason, the format of the partition does not display properly. As for vim, simple additions and deletions I already know. Be able to edit the files smoothly under Linux. I don't want to go deep in this. When I put this "bird's private food" to chew over the time, I go back to see these questions, it may be a lot easier.

Thinking of this place, I think of the days of leave. I have hardly shine to learn. I am not as inspirational as I planned, so I use my ascetic, to be an inspirational object, to move myself and others. Stick to the right direction if nothing unexpected happens. Can quickly go to success, realize their own value. But every day to bury themselves in the study, not happy at all. It is only after years of hard work that we enjoy happiness. It's better to be happy every day. Don't push yourself so hard every day. As long as the daily effort, just pure study, do not pressure too much baggage. Weekly weekend to give yourself a little vacation, complete indulgence. Don't want to study, just want to play. No, it's pretty good, too.

Always believe that no brain nonsense: love to laugh, the luck will not be too bad. Happy people, bad luck will be far away.

An operating system includes

Hardware

Kernel

Shell

Hardware is just a bunch of non-thought parts. Only the hardware, the computer is completely unable to work. Just like a bunch of men, if there is not a good standard of good leader, the disunity is unable to form a fighting force.

The kernel is the ability to identify each hardware, the ability to manipulate the hardware, let the hardware according to the instructions to work. But not every user can dictate to the kernel to let the hardware work directly through the kernel. First of all, most users will not command line, no professional knowledge background. Secondly, if the user can operate the kernel arbitrarily, it will bring great security hidden trouble to the system. Hack back more easily to invade your computer.

Based on the above reasons. The shell appears. The shell is on top of the kernel, and various applications are on the shell. For example, cool dog music This software: you click on the software to play music. The clicked behavior is first translated to the kernel through the shell. The kernel then communicates this behavior to the hardware, and the music is played out.

It's a big innovation for Microsoft to use a graphical shell,shell that has been integrated with the graphical interface in Windows. We used to think that Linux is not very good, it is very difficult to use. The first reason is that because Linux is a text interface, dark commands make people look scared. The second reason: too few Linux software. There is no way to meet the needs of our entertainment. But these things have changed a lot in recent years. There are also very stunning graphics to meet in various distributions of Linux. It's no less than Windows. such as the Bantu system, such as the Centos7 series, as well as my domestic deep Linux. As for the application software, I feel that compared with Windows is a lot less. However, if you do not play games, Linux provides software that is sufficient.

It's a little far away, get back to the chase. Linux has not only a graphical shell, but also a shell with a command interface.

When I installed Linux, it was the smallest installation, and the GUI was not installed by default.

The meaning of the Command interface shell is as follows (refer to bird's view)
1, installed forcing the first, installed forced the town building.

2, learn command line shell, can understand the essence of the command. Able to locate and solve problems accurately and quickly.

3, command interface, in the remote management than the graphical interface faster and more secure. Because the company has overseas business, the server is not Hong Kong, is the United States, the United Kingdom. Because of the international speed problem, you remotely use the graphical interface control to try.

As mentioned earlier, the shell is a translation of the user's behavior. Therefore, since it is a translator, then there can be no one interpreter. In the history of the development of Linux there are many translation officers. Bash,c Shell, K shell, TCSHL and so on. The shell we normally use is the Bourne Again Shell (bash), and why is that a name? That's because the first popular shell, written by Steven Bourne, was developed. To commemorate it, so get up a shell like this. The main idea is a shell starting from Bourne. It's a long history. Think about it, foreigners also have a feeling of it.

You can use Cat/etc/shells to see the following shells in your system that you can use.

Bash is the default shell in Linux, the official interpreter. The main advantages are the following points:

Command memory function: That is the Historyde function. By default, more than 1000 can be recorded.

The tab command and the completion function of the path. is simply the favorite of the lazy egg, a line often path, only need to press a few TAB key can complete the success, mother no longer have to worry about my memory.

The Settings feature of the command alias. Alias This I use not much, it is said to be very useful.

Job control, foreground, background control.

program scripting features. The OPS Engineer's favorite.

Common Linux Commands Explanation (fourth day)--bash section