Basic use of Linux CentOS (on)

Objective

For an operating system, the amount of software determines the ecological integrity of an operating system. The tools for managing the software help the operating system improve its own system.

In Windows, we can install software through EXE installation package or run green software, and now for the computer less skilled users, use?? The computer steward is a good choice, although the computer steward is convenient, but the related problems brought by it can not be ignored, these windows problems we press not to talk about.
On Mac, we have the App Store as our main tool for installing software. Apple's control over its own software ecosystem is in place, but we can also install the software using the Drag app file.

In Linux, the package manager plays an important role in this chapter, and later on, the Yum tool in CentOS, for example, describes how to install the software and how to do it.

It is important to note that if you use the Ubuntu system, package management software for Apt-get (older version) or apt (newer edition), the use of the same way and Yum is very different, but there are similarities, after the use of Yum to use apt in fact, there is virtually no learning cost.

Package Manager

Let's revisit what is Package Manager?

Package Manager is actually a package manager, it has a directory in the cloud or on-premises, listing all the software under the jurisdiction. When you need to install, uninstall, or inquire, it lists the software and installs it directly by default.
Usually different environments have different package managers, such as Mac has brew Package Manager, node has NPM Package Manager, Ruby has gem Package Manager and so on.
As one of the most stable systems, Cent's default Yum manager is well known and easy to use. You can say that 70% of the software can be installed and run flawlessly with Yum.

Where's the rest of the 30%?

Yes, the remaining part of the software can actually be installed with Yum. But sometimes there are some special cases.

For example, Yum installs the software version is usually older (in order to stabilize), sometimes the old unbearable, even if you change the Yum source has no way to upgrade, at this time we have to use a compile installation and other methods
Also, if you install different software that is dependent on each other, yum will usually handle it yourself, but if you have previously installed the software manually, the new software needs to rely on it, and so on, these Yum automation programs will not help you. Related questions we'll talk about it later.

Yum Install software

The installation process of Yum is briefly described below:

1. According to the user input, the possible user wants to install the software through regular matching.
2. Lists the software and waits for the user to confirm that it is installed.
3. Install the software and output to the default directory.
4. Configure the relevant environment variables.

In fact, these processes do not require user intervention, the user only need to confirm the installation at the time of installation is possible.
While installing the software, it is simple, for example we want to install VIM, only need:

[email protected] ~]# Yum install vim

• 1

In this case, the system will automatically give the software and ask you to confirm

..... Installing: vim-enhanced                 x86_64                 2:7.4.160-1.el7_3.1                 updates                 1.0 m Transaction summary ================================= ====================================================================================== Install  1 Packages total Downloads: 1.0 M installation Size: 2.2 MIs This OK [y/d/n]:

At this point, select Confirm.
Of course you can enter more packages to install at the same time

[email protected] ~]# Yum install vim gem

For the software, each system requires you to confirm, if you are bored, you can use the-y parameter.

[email protected] ~]# Yum install vim gem-y

If you can determine that the software is updated, we can update the first software with check and update

[[email protected] ~]# yum check-update vim[[email protected] ~]# Yum update vim

　　

Yum Management software

After the software is installed, we need to manage the software, how to manage it?
Use the list parameter to list

[email protected] ~]# Yum List installed

Of course, if you want to list a specific software or a class of software, you can use simple expressions.

[[email protected] ~]# Yum list yum* installed packages Yum.noarch                                                        3.4.3-150.el7.centos                        @anacondayum-metadata-parser.x86 _64                                        1.1.4-10.el7                                @anacondayum-plugin-fastestmirror.noarch                                   1.1.31-40.el7                               @ Anaconda Installable Packages Yum-networkmanager-dispatcher.noarch                              1.1.31-40.el7                               baseyum-cron.noarch                                                   3.4.3-150. El7.centos                        baseyum-langpacks.noarch                                              0.4.2-7.el7   

Note that it will list installed packages and packages that can be installed.
Of course, Yum also supports the use of some other parameter management software, such as the Info,search parameter

[email protected] ~]# Yum info vim[[email protected] ~]# Yum search vim

Yum Delete Software

Yum Delete Software is also very simple, using the Remove parameter can be,

[email protected] ~]# Yum remove vim

　　

End

This is roughly about Yum's common use.
You can install some software, such as PHP Java python vim net-tools, and so on, according to this issue. There are other interests can leave a message ah ~

Basic use of Linux CentOS (on)