1. What is linux
1. linux refers to the linux kernel
2. The operating system is the kernel of linux and the software of the GNU organization.
2. Open the terminal under the redhat system
1. Right click the mouse--->open terminal
2.Application--->Utilities--->Terminal
3.ctrl+shift+n ##Open a shell in a new window
4.ctrl+shift+t ##Open a new tab in the same window
3. About the shell
1. The shell is an interpreter
2. It is a file that protects the system kernel from being tampered with
3. Execute the command in the shell
(1) The command must be entered after the line prompt. Ctrl+C can end the program occupying the current prompt and release the line prompt.
(2) Command format: command+space+parameter+space+object
(3) The command is the program, the parameter is a function specified by the program (-a -b -c = -abc ), and the object is the operation target
(4)-parameter ##Word abbreviation
--parameter ##word full spell
4. The meaning of the line prompt
[kiosk@foundation2 Desktop]$
kiosk #user who opened the shell
@ #delimiter
foundation2 #Open shell host name
Desktop #Working directory name (the name of the current folder)
$ #User level ($ means normal user, # means super user)
Fourth, the control of the virtual machine
System shutdown: "poweroff" forced shutdown without reminder; "shutdown" has shutdown reminder, suitable for enterprises.
shutdown #shutdown
shutdown -c #Cancel shutdown
Power on the virtual machine
Ordinary user login: click student user--->enter password
Super user login: Click not listed?--->uaername to enter the super user name -->passwd to enter the password
Five, set the system language and input method
application--->systemctl tools--->settings--->region & lanuage--->Select the required input method
Click "+" to add different languages
6. Switch users
[kiosk@foundation2 Desktop]$ su - username
Switching from an advanced user to a low-level user does not require a password. Switching from a low-level user to an advanced user or switching to a level user requires a password. Both logout and exit can indicate that the user returns from the iy user to the last user.
su - / su - root both means switch to super user root
Seven, simple system commands
（1）date
watch -n 1 date ##Let the date command be executed every second, Ctrl+C launches the monitoring command
date 11181115 ##Set the system time to 11:15 on November 18 Format: xx month xx day xx hours xx minutes
date 111811152016.55 ##November 18, 2016 11:15:50
date +xday -xday ##View the time before or after x days
date +%... ##Set the output format of date
