Linux study notes super detailed 0 basics (medium)

Vi/Vim editor

Everything is a file under Linux. Vi editor and Vim editor can directly edit and operate text files. There is no big difference. Vim has color distinction and is more beautiful. Vim file path + file name can enter the general mode, the general mode It is a read-only file and cannot be manipulated.

Three modes of Vim editor

vim click to enter the file

i Click i to enter edit mode

esc exit edit mode

:w To save the changed content, you need to enter the command mode, click: and then click w, write

u If you don't want to write, you can press u to undo the edited content

:q Exit the three modes and switch to the directory

Commonly used editing commands under vim

In normal mode:

dw deletes a word, move the cursor to a certain word position, it will delete the characters behind the beginning of this character, if you want to delete a complete word, you need to move the cursor to the first position of the word.

edit mode:

command mode:

: or / Enter the command mode and perform an editing operation on the entire document.

Network configuration and system management operations

Use ifconfig to view the IP under Linux, and you can ping the IP of the virtual machine under the host.

You can see the IP of my host:

The IP under my virtual machine is:

It can be seen that the two are not in the same network segment, but they can communicate with each other. What is the reason?

This is to talk about the network connection mode in the virtual machine, as shown in the figure below, the virtual machine provides three network connection modes.

Bridge mode:

The mode in which the virtual machine is directly connected to the external physical network, and the host acts as a bridge. In this mode, the virtual machine can directly access the external network and is visible to the external network.

NAT mode:

The virtual machine and the host build a private network, and convert the IP through the virtual network address translation device, and the virtual machine shares the host IP

The external network can be accessed, but the virtual machine cannot be accessed from the external network.