1. What is linux
linux operating system #GNU /linux
#GUN is an open source organization
#linux refers to the linux kernel
Kernel##System Core Program
## Equivalent of Human Brain
##Responsible for system program and hardware allocation and scheduling
2. What is a shell
shell ##Provide the external operating system communication interface
##Internal implementation to protect the kernel
##The shell used by default in RHEL8 is bash
3. The meaning of shell prompt
shell
Types of
The shell used by default in rhel8 is bash
bash=GNU Bourne-Again SHell
How to open the shell
1. Right-click to open
2. Application ---->favorites------>terminal
3. gnome-terminal
4. When the shell is already open, you need to open a new shell, you can use + in the shell + Open
5. You can set any shortcut key in the settings to execute gnome-terminal
The line prompt of the shell command
[root@westoslinux Desktop]#
1 3 4 [5]
[5]: Identity prompt # indicates that the current user is a super user, $ the current user is a normal user
####4.Shortcut keys in shell###
1. Use of shortcut keys in the shell
++ ##Open multiple windows in one terminal
++ ##Reopen a terminal
+ ##Cancel command execution
+ ##Close the shell
++<mouse selected>+ ##Copy selected text
++ ## Paste
## Select the mouse to copy
##Press the mouse wheel to paste
2. How to execute commands in shell
1) Command execution format
Command parameter object
The command is the program. The
parameter represents the special function of the command. The
object is the operation target.
2) How to execute
commands Some commands can be executed individually.
Multiple parameters can be added
-a -b -c =-abc =-cba = -acb
parameter -s means the abbreviation
parameter -size means full spelling
The command must be entered after the prompt, otherwise the command cannot be executed.
When the command line is occupied, you usually use + to end the program executed by the command to release the command line.
**
5. Get help from the command line
**
whatis command RM ## See the basis of the use of
## view occurred during the
## RM: Nothing Appropriate
. # 1 pledged to view the contents without the help of
# 2 system helps update data is not updated with the mandb command.
"Note: When executing the whatis command, there is nothing appropriate in most cases because "
"The help database of the system is not updated, how to solve this problem, you need to execute mandb under the root user"
su-
mandb
rm --help ##View the basic usage of the command
[] ##The content can be added or not
... ##The number of content is arbitrary
<> ##Elements that must be added when the command is executed
man rm ##Detailed explanation of command usage man is the abbreviation of manual
man -k passwd ##passwd keyword how many levels of man
##man's level
#1 command
#2 system call
#3 function library call
#4 special files (device files, etc.)
#5 files
#6 games
#7 special Package
#8 System Management Command
#9 Kernel Information Rules
man rm ##Enter the command help of rm
q ##Exit
/Keywords##Search keywords, n matches down, N up matches
G ##Quickly move to the end of
mang ##Quickly move to the forefront of man
**
6.Linux command line history call
**
The shell we are currently using can record the history commands that have been executed in the system
##Refer to the history command
history -c ##Clear the current history command
##Clear the history permanently and need to clear the file.bash_history
263 westos-vmctl start westos_node1
264 westos-vmctl view westos_node1
265 rm -fr /etc/sysconfig/network-scripts/route-br0
266 su - root
267 wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-8.repo
268 su - root
269 westos
270 westos-vmctl start westos_node1
271 westos-vmctl view westos_node1
272 flame config
273 flameshot config
274 flameshot gui
275 flameshot config
276 flameshot gui
277 history
[kiosk@foundation40 Desktop]$ history
Invoke historical commands
上建|下key## Invoke line by line
! Number##Call the specified line history
! The character ##calls the recent history beginning with this character
+ ##Open the history search mode, the command line will become:
##（reverse-i-search): Enter the keyword
## will display the most recent one containing this keyword history
7.
Padded present in the system of commands, files, and parameters of certain commands
when you press tab does not work, this information represents the beginning of the characters are not the only press twice
as that will start with this character with the contents of the display
if 2 If this item is not displayed, it means that there is no command beginning with this character