Chapter23: Software Installation rpm,srpm and Yum (1)-Introduction to Software Manager

From the front we see, if the use of tarball for installation, each time the installation to detect the system, shunting compilation parameters, the actual compilation, and finally to see personal preferences to set the location of the software installation. This is very complicated,

If our Linux system is the same as a software company's system, then they can publish the executable software directly to the user after compiling it on their own system. There are some methods that are similar to window.

We add some information related to these programs in the installation time, set it up as a database, we can manage the software (installation, anti-installation, upgrade, etc.), there are two of these aspects on Linux, namely centos,red hat rpm and Debian dpkg.

I. RPM and DPKG

Linux developers first set up the software on a fixed system, the software related files packaged into a special format of the file, the file has a preview detection system and software-dependent script. Once the user obtains this software, the software file will be installed according to the internal

The script detects the presence of the relevant precursor software and installs it if the installation environment complies with it. After the installation is completed, the information of this software is also recorded in the software management mechanism, so as to facilitate the later removal of the upgrade.

Whether it is RMP or dpkg, we have to solve the problem of software attribute dependency, they make the data of trust attribute list, through the dependency list, the management mechanism will get the data automatically.

Distribution	Software Management mechanism	Using commands	Online Upgrade command
Red Hat/centos	Rpm	Rpm	Yum
Debian/ubuntu	DPKG	Dpkg	Apt-get

Two. RPM

RedHat package Manager, a mechanism for installing the software you want into your Linux system in a database way.

RPM Features:

The software is compiled and packaged into an RPM installation package with the extension xxx.rpm. The default database in the system records the software to be installed, and if the dependency property is satisfied when we install it, it is installed, otherwise it is not installed. When installed, The information for this software is written to the RPM database. So easy to install, and easy to query, anti-installation and so on.

But there are also problems:

This kind of software can only be installed in the original default hardware and system, The similarity requirement is very high. So the software published by different distribution is not used in any other distribution. Even different versions of the same distribution are not interoperable. So we need another way:

SRPM:

SOURCE RPM. The file contains the source code, and the extension is xxx.src.rpm. Unlike Tarball, the srpm content is the source code, but it contains the software's dependent software description and the data provided by all RPM files. And it's different from RPM, It also provides the parameter settings file (configure and Makefile). So when we install srpm, we need to

(1) First compile the software in RPM management, at which time the SRP is compiled into RPM.

(2) Install the completed RPM file into Linux.

So we install the environment can be different from the original author, this is the role of srpm.

Chapter23: Software Installation rpm,srpm and Yum (1)-Introduction to Software Manager