Summary of Linux common commands (recommended collection)

Summary of Linux common commands (recommended collection)

Some commonly used commands are collected here for viewing when needed, welcome to add. (The operations mentioned here are based on the CentOS system by default)

file management

directory operations

switch directorycd

view catalogls

• -lList file details or directly ll
• -aList all files and directories in the current directory, including hidden a(all)

Create a directorymkdir

• -pCreate a directory, if there is no parent directory, create p(parent)

output informationecho

print file to command line (view file)cat

Change the user who owns the filechown

change file groupchgrp

download filewget

Find a string in a text filegrep

Count the number of lines, words, and characters in the textwc

partially displayedmore/less

find filesfind / -name ‘auto.cnf’

create empty filetouch

copy filescp

move or renamemv

Delete Filesrm

• -rRecursive deletion, can delete subdirectories and files
• -fforce delete

delete empty directoryis rm

The tree structure displays the directory, and the tree package needs to be installedtree

show current directorypwd

Create link fileln

Display text file contents in pagesmore、less

Display file header and tail contenthead、tail

vim operation

enter the editorvi/vim, vim three modes: command mode, insert mode, edit mode. Use ESC or i or : to switch modes.
enter edit mode inserti
exit edit modeesc
Save: enter laterw
Exit: enter laterq
Exit without saving: enter laterq!
show line numberset number
Find the key==/xxxx== Press n to jump to the next one, shift+n to the previous one
Copy the line where the cursor is and paste ityyp
h (move one character left ←), j (next line ↓), k (up line ↑), l (move one character right →)

Packing and compression related commands

Compressiontar\gzip\bzip2
-carchive files
-xCompressed file
-zgzip compressed file
-jbzip2 compressed files
-vShow compression or decompression process v(view)
-fUse the file name
Example:
only package, no compression:tar -cvf /home/abc.tar /home/abc
Pack and compress with gzip:tar -zcvf /home/abc.tar.gz /home/abc
Pack and compress with bzip2:tar -jcvf /home/abc.tar.bz2 /home/abc
If you want to decompress, just replace the above command directlytar -cvf / tar -zcvf / tar -jcvfJust replace the "c" with "x".

Linux pipeline

Use the standard output of one command as the standard input of another command. That is to use several commands in combination, and the latter command divides the result of the previous command.
Example:
grep -r "close" /home/* | more Search all files in the home directory, including close files, and output them in pages.

File permission management

Three Basic Permissions

R: read, the value is expressed as 4
W: Write, the value is expressed as 2
X: Executable, the value is 1

[root@VM-16-2-centos ~]# ll
total 597952
-rw------- 1 root root  12387614 Aug 29  2021 apache-zookeeper-3.7.0-bin.tar.gz
-rw-r--r-- 1 root root 113304268 May  3 12:22 jdk-8u281-linux-x64.rpm

As shown above,jdk-8u281-linux-x64.rpmThe permissions of the file are ==-rw-r–r–, a total of ten characters, divided into four paragraphs.
The first character "-" indicates an ordinary file; this location may also appearlLink;dIndicates
the second, third and fourth characters of the directoryrw-Indicates the authority of the current user, so it is expressed as 4+2=6,
the fifth, sixth and seventh characters in numerical valuesr–Indicates the permissions of the current group, so it is expressed as 4,
the eighth and ninetieth characters in numerical valuesr–== indicates other user permissions, so it is expressed as 4 in numerical value,
so the authority to operate this file is expressed in numerical value as 644

change permissions

Change permissions:sudo chmod[u belongs to the user g belongs to the group o other users a all users] [+increase authority-decrease authority] [rwx] directory name

For example: there is a file filename, the permission is ==-rw-r----x==, change the permission value to ==-rwxrw-rx==, expressed as 765 in numerical value

sudo chmod u+x g+w o+r filenameIt can also be expressed numericallysudo chmod 765 filename

run the program

command line run

Run ==./filename==

quitctrl+c

Background process

runnohup command >out.file 2>&1 &

quitps -ef |grep keyword|awk '{print $2}'|xarg kill -9

Run as a service

Set bootsystemctl enable

start upsystemctl start

closuresystemctl stop

system related

system management commands

Display the detailed information of the specified file, more detailed than lsstat

Show online login userswho

Display the current operating userwhoami

show hostnamehostname

show system informationuname

Dynamically display information about the process that currently consumes the most resourcestop

Show momentary process statusps\ps-aux

View directory sizeyou -h /home(with unit display catalog information)

View disk sizedf -h(display disk information with units)

Check network statusifconfig

Test network connectivityping

Show network status informationnetstat

The command will not be used anymore, see the document such as:man seized

[root@VM-16-2-centos ~]# man grep
GREP(1)                    General Commands Manual                       GREP(1)
NAME
       grep, egrep, fgrep - print lines matching a pattern

SYNOPSIS
       grep [OPTIONS] PATTERN [FILE...]
       grep [OPTIONS] [-e PATTERN | -f FILE] [FILE...]
……

clear screenclear

Rename the commandalias,like:alias showmeit="ps -aux", deactivate the use ofunaliax showmeit

kill processkill, you can first usepsortopcommand to view the id of the process, and then use the kill command to kill the process.kill -9force delete

firewall

View firewall statusfirewall-cmd --state

stop firewallsystemctl stop firewalld.service

Prohibit firewall from bootingsystemctl disable firewalld.service

shutdown and restart

shutdownshutdown -h now
-r shut down and restart
-h shut down without restarting
now shut down and
restart immediatelyreboot

shutdownhalt

Network Configuration

View network card informationifconfig

Network Configuration/etc/sysconfig/network-script/ifcfg-eth0

Configure network card/etc/udev/rules.d/70-persistent-net.rules

User Management

create useruseradd

set passwordpasswd
storage group account/etc/group
System User Profile/etc/passwd

Store passwords for user accounts/etc/shadow

Store the password of the user group account==/etc/gshadow==

usernameuseradd

usernameuserdel

usernameadduser

group namegroupadd

group namegroupdel

Set a password for rootpasswd root

su root

su - root

System environment variable==/etc/profile==

user environment variablesbash_profile

User environment variable ==.bashrc==

su userSwitch users, load the configuration file .bashrc

su - userSwitch user, load configuration file /etc/profile, load bash_profile

Change the user and user group of the file

sudo chown [-R] owner[:group] {File|Directory}

-rw-r--r-- 1 root root 113304268 May  3 12:22 jdk-8u281-linux-x64.rpm

For example: returnjdk-8u281-linux-x64.rpmas an example. Belongs to user root, group root

To switch the user and group to which this file belongs. command can be used.

sudo chown daley:java jdk-8u281-linux-x64.rpm

install software

How to download the rpm installation package

Installrpm -i jdk-XXX_linux-x64_bin.rpm

look uprpm -qa | grep jdk

the listrpm -qa | more

ubuntu dpkg 方式

查找dpkg -I | grep jdk

列表dpkg -I | more

安装dpkg -i jdk-XXX_linux-x64_bin.deb

yum way

searchyum search jdk

Installyum install java-11-openjdk.x86_64

deleteyum erase java-11 -openjdk.x86 64

configuration file/etc/yum.repos.d/CentOS-Base.repo

ubuntu apt-get 方式

搜索 apt・cache search jdk

安装apt-get install openjdk-9-jdk

删除apt-get purge openjdk-9-jdk

配置文件/etc/apt/sources. Iist

How to download compressed files

edit .bashrc

Environment variable configuration
Open the environment variable filevi /etc/profile
Configure environment variablesexport JAVA_HOME=/root/j d k-XXX_lin ux-x64
export PATH=$JAVAHOME/bin:$PATH
refresh configurationsource /etc/profile
Finally, everyone is welcome to ask questions and communicate.