First, Introduction
When we install the software on the Windows system, we add some information related to these programs, and set him up as a database, we can implement software installation, uninstall, upgrade and verification, similar to the "Add Remove Program" of Windows. Because the source package is used to set up compilation parameters on Linux systems, the actual compilation, and finally the necessary way to install the program, this process is cumbersome, and for users unfamiliar with the entire system is a burden, so later in our Linux system to have two common suite management procedures, RPM and Debian are the dpkg, of which RPM is the most common, so late we are below to introduce the next RPM.
The full name of RPM is "RedHat Package Manager", as the name suggests it was developed by the RedHat company. RPM is a database record to install the required suite to the Linux host a set of management program, it is the biggest feature of the package will be installed first compiled and packaged, through the packaged suite in the default database records, the package at the time of installation of the property module. At the time of installation, RPM will query the host's dependency property suite for the information of the records in the kit, and install it if satisfied. If you are not satisfied with the installation, installation, the package will be written to all the data in the RPM database, to facilitate future query, verification and uninstall. The advantages of doing this:
1, due to the completion of the compilation and packaging, all easy to install.
2, because the package information has been recorded in the Linux host database, easy to query, upgrade and uninstall.
Of course, it also has its drawbacks, because all the data has been compiled, so the installation must be installed when the host environment, that is, the original installation of this suite environment, must be on the user host, if not appear can not be installed. The main disadvantages are as follows:
1, the installation environment must be packaged with the environment in line
2, need to meet the dependency property requirements of the suite
3, unloading needs to be particularly careful, the bottom of the package can not be deleted first, or the entire system may cause problems.
The RPM program's database location is/var/lib/rpm, which defines all the attributes of RPM management, of course, if we can update this database,
RPM--REBUILDDB: Rebuilding the database is sure to be re-established.
RPM--INITDB: Initialization of the database, not only to build, there is no need to build.