Understanding of RPM applications

Article Title: Understanding of RPM applications. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.
Author: Yu Yiqi Zhao Jianli
　　
RPM is the abbreviation of RedHat Package Manager, which is the RedHat (red hat) Package Manager. (RedHat is a famous American LINUX company, website: http://www.redhat.com)
　　
For an operating system, there cannot be a similar package manager. Without the help of the software package manager, the producer of the operating system release version will face one or more difficulties. it will be very troublesome for users to install, upgrade, uninstall and release software packages, system management is also prone to problems. On the contrary, with a dedicated software package manager, software producers can easily create and release their own software. for common users, installation and maintenance of software packages will become very convenient. In this case, it will also play a good role in promoting the promotion of an operating system. With the popularity of the RedHat LINUX release, RPM has been quickly promoted.
　　
RPM pioneer
　　
At first, the release of the LINUX system did not use any software package manager. Over time, the redhatm Linux developer realized the importance of developing a software package manager and developed the RPP manager.
　　
RPP is simple compared with RPM, but there are several important functions. for example, you can install and uninstall the software by running a simple command, the package can contain script programs executed before and after installation and uninstallation, and can verify installed software packages at any time. the query function is also very powerful.
　　
The disadvantage of RPP is that RPP packaging is based on specially modified (for RPP) source code, so these source code is not pure source code. For this reason, when software package developers want to build a large number of different software packages, they will face many technical problems. RPP cannot guarantee that the current execution program is based on the packaged source program, and RPP does not support the multi-processor architecture.
　　
PMS (package management system, software package management system), which is developed together with RPP, is another group of LINUX enthusiasts. PMS uses pure source code, which allows the software package maker to release the latest version of the software quickly, and can immediately see the changes to the software. RPM adopts this wise practice, which is also a significant contribution of PMS to RPM. The disadvantage of PMS is that the query function is not strong, there is no package verification function, and multi-architecture is not supported, and the database design is not good.
　　
After RPP and PMS, Rik Faith and Doug Hoffman developed the PM manager. The manager integrates many functions of RPP and PMS, but the database design is not strong yet and does not support multi-architecture.
　　
RPM Development
　　
Afterwards, Marc Ewing and Erik Troan developed the RPM Package Manager (RPM1.0) in PERL based on their experience in RPP, PMS, and PM design.
　　
Its success lies in:
　　
· The configuration file can be automatically processed;
　　
· A large number of software packages can be rebuilt;
　　
· Easy to use.
　　
Its shortcomings are:
　　
· The program is large and runs slowly because it is written in an interpreted language such as PERL;
　　
· The database features are too weak;
　　
· Multi-architecture is not supported;
　　
· The Package File format cannot be expanded.
　　
To address the weakness of RPM1.0, RPM developers once again strive to upgrade RPM to version 2.0, 3.0, and the current version 4.0. They mainly do the following:
　　
· Rewrite the program with C, which greatly improves the RPM running speed.
　　
· The RPM database format is re-designed, focusing on improving both performance and reliability.
　　
· The software package format is also re-designed to facilitate future expansion and upgrade.
　　
· Rpmlib (RPM function library) is created to facilitate other programs to call RPM.
　　
· Multi-system support is added to facilitate cross-platform use of RPM (whether it is x86 or other systems such as Linux or Linux ).
　　
Online RPM
　　
RPM official website for http://www.rpm.org, the site published the latest RPM news, instructions on RPM documentation, you can also download the latest RPM software source code and execution code, may wish to go to see.
　　
Summary
　　
Nowadays, RPM makes it easier to install and uninstall software packages. it also makes it easier to verify whether installed software packages are normal. it also makes packaging programs (source programs or execution programs) simple and supports cross-platform, following the source code published by GPL copyright, RPM is widely used and promoted. RPM is popular in the LINUX and non-LINUX worlds. If you want to know or even master RPM, please come with me!