Linux foundation 06

Linux There are three ways to install software in

 Installation mode 
	1.rpm install 
		rpm The installation is similar to windows Installation package in , Download it and install it directly .
		 The disadvantage is that you can't solve the dependence by yourself 
	2.yum install 
		yum The installation is based on rpm install , That is to say rpm The function of automatically resolving dependencies is added to the .
	3. Source code compilation and installation 
		 Source code installation by compiling source code , Get the package . The advantage is that you can customize the software package ,
		 The disadvantage is that it's more complicated 

1.rpm install

 install ：rpm -ivh [ Package name ]
	 uninstall ：rpm -e [ Package name ]
	 upgrade ：rpm -Uvh [ Package name ]

	1、 Download installation package 
	
	2、 install 
        [[email protected] ~]# rpm -ivh zsh-5.0.2-34.el7_8.2.x86_64.rpm 
        Preparing...                          ################################# [100%]
        Updating / installing...
        1:zsh-5.0.2-34.el7_8.2             ################################# [100%]
	
	3、 uninstall 
		[[email protected] ~]# rpm -e zsh
	
	4、 to update 
        [[email protected] ~]# rpm -Uvh zsh-5.0.2-34.el7_8.2.x86_64.rpm 
        Preparing...                          ################################# [100%]
        Updating / installing...
        1:zsh-5.0.2-34.el7_8.2             ################################# [100%]

	5、 Package name 
		zsh-5.0.2-34.el7_8.2.x86_64.rpm 
             Package name ：zsh
             Version number ：5.0.2
             How many times to compile ：34
             Applicable platforms ：el7_8（CentOS 7）
             Applicable system digits ：x86_64
             Extension ：rpm

	6、 View the configuration file of the package 
		[[email protected] ~]# rpm -qc zsh
	
	7、 Check whether a software is installed 
		[[email protected] ~]# rpm -q zsh

	8、 Check which software is currently installed in the system 
		[[email protected] ~]# rpm -qa
		
	9、 Check the installation path of the software , See what's installed 
		[[email protected] ~]# rpm -ql zsh

2.yum install

 Upload and download ：yum install lrzsz -y
	 You can drag the physical machine software directly into the virtual machine 

 be based on rpm install , Resolve dependencies automatically .

1、 install 
	yum install [ The name of the package ] 
	
	 Parameters ：
		-y :  No interaction 
		--nogpgcheck :  Ignore public key authentication 

2、 uninstall 
	yum remove [ Package name ] 
	
	 Parameters ：
		-y :  No interaction 

3、 to update 
	yum update [ Package name ]
	 Parameters ：
		-y :  No interaction 
	
	 Be careful ： If it is followed by the specific package name , The specified package will be updated ; If not specified , Then update all software packages that need to be updated in the system .
	
4、yum Installation lifecycle 
	
	1、 perform yum install zsh -y
	2、 Go to  /etc/yum.repos.d/  Find out  .repo  Final document 
	3、 adopt  .repo  Links in files , Find the corresponding software warehouse 
	4、 Download the specified software package in the corresponding software warehouse 
	5、 Cache to  /var/cache/yum/
	6、 According to cache , Install package 
	7、 Remove package （keepcache  Whether to save the cache ,0  Means not to save  , 1  Save on behalf of ）
	
	 notes ：/etc/yum.conf  yes yum Configuration file for .

3. System security optimization

1、selinux
	 close selinux
		1. Permanent ban  		 System restart takes effect 
		 Get into vim /etc/selinux/config Edit... In the configuration file 
			 The function is permanently turned on ：enforcing
			 Function temporarily off ：permissive
			 The function is permanently closed ：disabled
		2. Temporarily Closed 	
		setenforce o			

2、firewalld
	 Permanently shut down firewall 
		systemctl disable --now firewalld
		--now :  Execute now 
firewalld   --->  iptables  --->  System security framework 
 At the top                Bottom 				 At the bottom 
 Security group 
vpn iptables

4. Prevent system garbled code optimization

en_US.UTF-8		:  U.S. English ,utf-8
zh_CN.UTF-8
zh_HK.UTF-8

 Temporary optimization 
export LANG=zh_CN.UTF-8  :  Set encoding 

 Permanent optimization 
vim /etc/locale.conf