Developers must have a Linux command

Linux developers commonly used commands necessary to master these commands absolutely enough, based on CenterOS7.6.

System Management Services

systemctl

Output status of each service system:

systemctl list-units --type=service

View the running status of the service:

systemctl status firewalld

Close Services:

systemctl stop firewalld

Start the service:

systemctl start firewalld

Restart the services (regardless of the current service is started or shut down):

systemctl restart firewalld

Reload the configuration information without interrupting service:

systemctl reload firewalld

Prohibit service boot from the start:

systemctl disable firewalld

Set service boot from the start:

systemctl enable firewalld

Document Management

ls

Lists the current directory (/) all the files under:

ls -l /

pwd

Gets the current working directory where the absolute path

cd

Change the current working directory:

cd /usr/local

date

Display or modify the system time and date;

date '+%Y-%m-%d %H:%M:%S'

passwd

Used to set user passwords:

passwd root

its

Change the user identity (switch to superuser):

su -

clear

Clears the screen information

man

Displays help information for the specified command:

man ls

who

Discover what the system is run level:

who -r

Displays the current user logged on to the system:

who -buT

free

Displays the system memory status (in MB):

free -m

ps

Dynamic Display System processes running:

ps -ef

View sshd running dynamic process:

ps -ef | grep sshd

top

View real-time dynamic process, similar to Windows Task Manager

mkdir

Create a directory

When the paging file is too long for viewing the contents of the file 10 lines per page View boot.log file

more -c -10 /var/log/boot.log

cat

View Linux boot log file and line number indicate:

cat -Ab /var/log/boot.log

touch

Create a file text.txt:

touch text.txt

rm

Delete Files:

rm text.txt

Forced to delete a directory and its subdirectories:

rm -rf testdir/

cp

Test1 test2 to copy the directory to the directory

cp -r /mydata/tes1 /mydata/test2

mv

Move or overwrite the file:

mv text.txt text2.txt

Compression and decompression

takes

The file / etc folder to the archive file etc.tar (not compressed):

tar -cvf /mydata/etc.tar /etc

File / etc are compressed with gzip folder to the etc.tar.gz:

tar -zcvf /mydata/etc.tar.gz /etc

With bzip2 compressed folder / etc to file /etc.tar.bz2:

tar -jcvf /mydata/etc.tar.bz2 /etc

Page View archive content (gzip):

tar -ztvf /mydata/etc.tar.gz |more -c -10

Unzip the file to the current directory (gzip):

tar -zxvf /mydata/etc.tar.gz

Disk and network management

df

Check disk space occupancy:

df -hT

ie

View the current file and share files in a directory folder size:

du -h --max-depth=1 ./*

ifconfig

Displays the current status of network interfaces

netstat

View the current routing information:

netstat -rn

View all active TCP connections:

netstat -an

View the system start listening service:

netstat -tulnp

View system resources in a connected state:

netstat -atunp

wget

Download the file from the network

Installation and management software

rpm

Install the package: rpm -ivh nginx-1.12.2-2.el7.x86_64.rpm
Fuzzy Search packages: rpm -qa | grep nginx
Exact Match packages: rpm -qa nginx
Query package installation path: rpm -ql nginx-1.12.2-2.el7.x86_64
View summary information package: rpm -qi nginx-1.12.2-2.el7.x86_64
Verify the contents of the package and installation files are consistent: rpm -V nginx-1.12.2-2.el7.x86_64
Update Packages: rpm -Uvh nginx-1.12.2-2.el7.x86_64
Remove a package: rpm -e nginx-1.12.2-2.el7.x86_64

yum

Install the package: yum install nginx
Checks can be updated package: yum check-update
Updates the specified package: yum update nginx
Look for package information repository: yum info nginx *
All listed packages already installed: yum info installed
Lists the package name: yum list nginx *
Fuzzy Search packages: yum search nginx