Linux basic commands and linux basic notes

Linux basic commands and linux basic notes

Today, we are building a Linux production environment. This is a complex task that has to be done. Although I have done it many times, there are still many steps and commands that I don't remember. Every time I find information everywhere, it is very troublesome. So I wrote down some steps for searching.

Log on to the remote MySQL database

mysql -h 192.168.1.100 -u root -p

Assign permissions to non-root accounts of MySQl

Grant select, insert, update, and delete permissions to all tables in the testDB database of the user whose user1 password is 123456:

grant select,insert,update,delete on testDB.* to user1@'%' identified by '123456';

Refresh permission:

flush privileges;

View the maximum number of connections in MySQL

show variables like 'max_connections';

Modify the maximum number of connections

vi /etc/my.cnf

Findmax_connections=100(If not, add it), and change:

max_connections=1500

Password-free logon to Linux servers

Use your computer to log on to the Linux server without a password (You are a Windows system)

On windows

Run the following command in cmd:

ssh-keygen -t rsa

Press enter under 3, which can be in the user directory of drive C..sshFolder,

Id_rsa is the private key and id_rsa.pub is the public key.

On linux

Run,

ssh-keygen -t rsa

Press enter three times, and thencd .ssh/As you can see,

id_rsa  id_rsa.pub

Create a public key used to save the login-free host,authorized_keys

touch authorized_keys

Change his permissions to 600

chmod 600 ~/.ssh/authorized_keys

Finally, write the id_rsa.pub public key of the windows computer to authorized_keys and save it.

File rename

The downloaded JDK file name looks like thisjdk-8u65-linux-x64.rpm\?AuthParam\=1445848743_f162eddc392f630f3b14bcded3bc3f19Change itjdk-8u65-linux-x64.rpm. The command is as follows:

mv jdk-8u65-linux-x64.rpm\?AuthParam\=1445848743_f162eddc392f630f3b14bcded3bc3f19 jdk-8u65-linux-x64.rpm

Install JDK

Download JDK

wget http://download.oracle.com/otn-pub/java/jdk/8u65-b17/jdk-8u65-linux-x64.rpm?Auth Param=1445848743_f162eddc392f630f3b14bcded3bc3f19

Download and rename it to jdk-8u65-linux-x64.rpm, and grant 777 permissions.

`chmod 777 jdk-8u65-linux-x64.rpm`

Install

rpm -ivh jdk-8u65-linux-x64.rpm

View

java -version

Configure Environment Variables

Modify the system environment variable File

vi + /etc/profile

Append the following content to the file:

JAVA_HOME=/usr/java/jdk1.8.0_65JRE_HOME=/usr/java/jdk1.8.0_65PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/binCLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JRE_HOME/libexport JAVA_HOME JRE_HOME PATH CLASSPATH

Make the modification take effect immediately:

source /etc/profile 

Install nginx directly using centos yum

Processing Source:

rpm -ivh http://nginx.org/packages/centos/6/noarch/RPMS/nginx-release-centos-6-0.el6.ngx.noarch.rpm

View the nginx information of yum:

yum info nginx

Installation:

yum install nginx

Start nginx:

service nginx start

Enter the host address to view the information:

Http: // 192.168.1.100/

See,

Welcome to nginx!If you see this page, the nginx web server is successfully installed and working. Further configuration is required.For online documentation and support please refer to nginx.org.Commercial support is available at nginx.com.Thank you for using nginx.

It indicates the operation is successful.

*Write down these records for now, and sort out the updates later. (Some Linux versions may not be fully applicable)