What tool is linux yum?

In Linux, yum is a software package manager that exists specifically to solve package dependencies; yum is an improved RPM software manager, which can well solve the software package problems faced by RPM. Dependency issues. When the administrator uses yum to install an RPM package, yum will first download the dependency file of the package from the server side, and then download and install all related RPM packages from the server side at once by analyzing this file.

#The operating environment of this tutorial: linux7.3 system, Dell G3 computer.

What is yum tool

yum, the full name is "Yellow dog Updater, Modified", is a tool that exists specifically to resolve package dependencies. package manager. Just like on Windows systems, you can use 360 ​​Software Manager to achieve one-click installation, upgrade, and uninstallation of software. Linux systems also provide such a tool, which is yum.

It can be said that yum is an improved RPM software manager, which well solves the software package dependency problem faced by RPM.

yum stores all RPM packages on the server side and records the dependencies between each package in files. When the administrator uses yum to install the RPM package, yum will first download the package from the server side. Dependency file, by analyzing this file, download all related RPM packages from the server at once and install them.

The yum software can be installed using the rpm command. Before installation, you can check whether yum has been installed by running the following command:

[root@localhost ~]# rpm -qa | grep yum
yum-metadata-parser-1.1.2-16.el6.i686
yum-3.2.29-30.el6.centos.noarch
yum-utils-1.1.30-14.el6.noarch
yum-plugin-fastestmirror-1.1.30-14.el6.noarch
yum-plugin-security-1.1.30-14.el6.noarch

You can see that yum has been installed on the system.

yum source detailed explanation

Definition

Before using yum to install the software package, you need to specify it The location where yum downloads the RPM package. This location is called the yum source. In other words, the yum source refers to the source of the software installation package.

When using yum to install software, at least one yum source is required. The yum source can either use the network yum source or use the local CD as the yum source.

Network yum source construction

Under normal circumstances, as long as the host network is normal, you can directly use the network yum source without making any modifications to the configuration file.

The network yum source configuration file is located in the /etc/yum.repos.d/ directory, and the file extension is ".repo" (as long as the file with the extension "*.repo" is the yum source configuration document).

[root@localhost ~]# ls /etc/yum.repos.d/
CentOS-Base.repo
CentOS-Media.repo
CentOS-Debuginfo.repo.bak
CentOS-Vault.repo

You can see that there are 4 yum configuration files in this directory. Normally, the CentOS-Base.repo file takes effect. We can try to open this file with the following command:

[root@localhost yum.repos.d]# vim /etc/yum.repos.d/ CentOS-Base.repo
[base]
name=CentOS-$releasever - Base
mirrorlist=http://mirrorlist.centos.org/? release= $releasever&arch=$basearch&repo=os
baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
…省略部分输出…

This file contains 5 yum source containers. Only the base container is listed here. The other containers are similar to the base container. The meanings of each parameter in the base container are:

• [base]: container name, must be placed in [].

• name: Container description, you can write it yourself.

• mirrorlist: Mirror site, this can be commented out.

• baseurl: The address of our yum source server. The default is the official CentOS yum source server, which can be used. If you feel it is slow, you can change it to your favorite yum source address.

• enabled: Whether this container is valid. If it is not written or written as enabled, it means that this container is valid. If it is written as enable=0, it means that this container is not valid.

• gpgcheck: If it is 1, it means that the digital certificate of RPM is valid; if it is 0, it means that the digital certificate of RPM is not valid.

• gpgkey: The location where the public key file of the digital certificate is saved. No need to modify.

Local yum source

If the Internet is not available, yum can consider using a local CD (or installation image file) as the yum source.

Related recommendations: "Linux Video Tutorial"

The above is the detailed content of What tool is linux yum?. For more information, please follow other related articles on the PHP Chinese website!