Most of those using linux use the command line mode, which is also more convenient for remote maintenance, because the command mode transmission takes up very little resources. X windows (graphical user interface) exists as a plug-in of linux graphical interface, which is not necessary. If you are playing with graphics, the graphical interface of unbuntu linux is gorgeous, which is biased towards individual users.

How to connect linux remotely

First, we need to get the IP address of linux.

Here, after logging into centOS (explained on the basis of the previous article "linux Installation and hard disk partition"), right-click the desktop "open terminal port" ------ type in: ifconfig command to view the local IP

What I marked with a red line is the ip address of the linux system.

Let's choose the remote login tool.

There are many remote login tools. You can use any remote login tool you like. The author recommends two for novices:

PuTTY: free, very small (only a few hundred KB), easy to operate, supports ssh1 and SSH2 (Protocol), and basically meets the requirements.

SecureCRT: charging. Compared with PuTTY, the volume is larger, more than ten MB. The large volume brings powerful functions and less ugly interface. It supports SSH (ssh1 and ssh2) telnet and rlogin protocols. It is used for connection and operation, including Windows,UNIX And VMS are ideal tools for remote systems.

The author uses the first paragraph to introduce tools in the same way.

Tips:

SSH protocol is similar to ftp and telnet protocols, but ftp and telenet are plaintext transmission. The database is encrypted during SSH transmission, so it is more secure. Another feature is that the transmitted data is packaged to make the data transmitted on the network in a smaller volume.

Click the Open button to log in. Enter the user name (root) and enter the password (the * sign is not displayed in the input process). If the user name and password are correct, the login is successful.

Solution to the garbled code problem of PuTTY terminal:

http://jingyan.baidu.com/article/3aed632e5f00ae701080913a.html

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linux common commands

On the study of linux commands, I believe no one will come up with a complete list of linux commands! So many orders are killing you. And bad memory, easy to forget. My method is to remember what I use. It won't be used much. Naturally, it will be recorded.

Tip: I don't know how many people have used gadgets like Youdao notes. You can save some commonly used commands in your notes with instructions, and check which one you use during operation. Don't try to remember.

Here are the commands that novices must know:

Switch between folders

ls     Displays all files and folders in the current directory   
cd  /user  open user folder
 If you do not know the full name of the folder you want to open or the name is too long, you can press tab The keyboard is automatically supplemented, such as: cd  /u + table Key, the system will help us fill it up automatically /user 
cd ..    ((followed by a space plus two points) return to the previous level directory

It's super simple. It's no problem to remember the above several and jump around between folders.

File operation

establish

mkdir  test    create folder
touch  test.txt   create a file

edit

vi test.txt  open test.txt file

c   Press on the keyboard C Key to switch from read-only to edit
Esc   Switch from edit state to read-only state
: q    Yes exit (when the file has not changed)
: q!    Exit without saving (when the file changes)
: wq   Save and exit

copy
cp test.txt  test2.txt   hold test.txt Files copied from the current folder test2.txt

cp test.txt  /hzh/test   take test.txt Copy to/hzh/test  Under the directory 

delete
rm  aa.txt  delete aa.txt file
rm  -r  bb  delete bb Directory (including all files in the directory) 

move
mv dd.txt ..  take dd.txt Move files to the upper directory (note the two points at the end)
mv bb.txt  /hzh/test/  take bb.txt Move files to hzh/test/Under the directory

Rename
mv  dd.txt  dd2.txt  take dd.txt Renamed dd2.txt

lookup
locate  aa.txt   Check the information in the whole system aa.txt Documents, locate\slocate The command is followed by a file or folder. However, you need to update the database before executing this command, so choose execute updatedb Command.

how?! Just remember the above commands. Congratulations! You can add, delete, modify, check and move files and folders.

View system information command

df -lh  View disk information

lsb_release -a   View all version information of the system

free  View memory information

             total       used       free     shared    buffers     cached
Mem:       1034536     294568     739968          0      15636     174944
-/+ buffers/cache:     103988     930548
Swap:      1052248          0    1052248

The following is an explanation of these values:
　　total:Total physical memory size.
　　used:How large has been used.
　　free:How many are available.
　　Shared:The total amount of memory shared by multiple processes.
　　Buffers/cached:The size of the disk cache.
　　Third line(-/+ buffers/cached):
　　used:How large has been used.
　　free:How many are available.
　　The fourth line doesn't explain much. 


ps View currently running processes
kill -9 QQ.exe   Terminate the process,-9 Indicates that the process is forced to stop immediately 

Shutdown command

shutdown now  Turn it off immediately
shutdown +5   5 Shutdown in minutes
shutdown 23:10  Set the system to shut down at 23:10
shutdown -r now  Shut down and restart the system immediately

Concept of pipeline: connect the front output with the rear input

For example, I have to take off my clothes before I go to bed. I can execute two commands, 1. Take off your clothes 2. sleep But through the pipe, I can write two steps together: undressing and sleeping. Of course, I can also write three or four steps (commands) together, but the former command must be a prerequisite for the latter command. Like the example I gave, I can't go to bed before I take off my clothes.

For example: # ls -l | more -l displays all the results, "|" is connected, and more is displayed in separate screens

There are so many linux commands that you can't finish learning. If you want to understand the usage of a command, you can follow a command with -- help to view the parameters. My view is to use which Google and which, and then record it in the notebook for future reference.

The above is Liangxu tutorial network Share Linux related knowledge for all friends.