Yellowdog Updater, Modified
History
To make it easier to install RPM packages and administer the program YUP was written and placed under the GNU General Public License for Yellow Dog Linux. YUP was very slow because it to dissolve the dependencies downloaded always all packets instead of only the important headers of each packet. Seth Vidal wrote a modified version and gave it the name " yellowdog updater modified". This was gradually expanded to the present state. After YUM was powerful enough and had enough features, it was also used by the Red Hat distribution assumed.
Meanwhile, openSUSE YUM supports rudimentary, except that by default on ZYpp.
Operation
In the / etc / yum.conf file all necessary configurations of the program are stored, the package sources can be found in the directory / etc / yum.repos.d /. The package repositories (English for warehouse, depot ) may be local directories, CDs, HTTP or FTP server. If the program is invoked, it first searches all registered repositories for new packages. If that is found, it will download the headers of the packet. These headers, for example, include the name of the package dependencies to other packages, files contained, version, etc.
After updating the packet data and a comparison with the local package database the program will behave according to the transferred command option. If it was passed around with the yum install firefox option, it then looks in the headers for the package firefox and loads the appropriate package along with all other associated packages down. If the option is yum upgrade, so all packets on the local system to be replaced, of which there is in the repositories a newer version. This option is also executed when a service such as an automatic system PackageKit performs update.
YUM download the required for an installation or an update RPM packages from repositories and temporarily stores it on the hard disk. For the installation procedure itself and the administration of the package database, YUM calls in the background on the program RPM.
Special
A special feature of YUM over other package managers is that YUM can be configured so that there is a cheap server out looking at each call from a list on the Internet, instead of always only want to access the same. This dynamic configuration also allows you to switch to other servers on the fly, if a server fails or should turn out to be not up to date.
Furthermore YUM can be expanded almost by a plug-in interface. The plugins is thus written in Python. Among the functions that are implemented by plugins, include the monitoring of connection speeds to the download servers and selecting the fastest server and automatically updated from external kernel modules when installing new kernel.
Frontends
YUM is a software for the command line that was delivered in the first versions of Fedora without graphical front-end. This changed the first time, as the based on Fedora Linux Linux distribution Cobind the program GYUM integrated, which offered an adapted to the Gnome environment graphical interface. GYUM was first adopted by the Fedora Core community, but version 2.1 of YUM further development in favor of pup has been set.
Meanwhile, there are several graphical front ends for YUM. Particularly noteworthy are Yum Extender ( yumex ) and kyum that were included in the Fedora distributions and are actively developed.
For Fedora Core 5 to Fedora 8 is a graphical update tool called a pup is ready, which is based on YUM. In addition, there is also a graphical package management interface ( " frontend " ) called pirut, which relies on YUM and its functions in addition to the installation CDs.
Since Fedora 9 PackageKit is used as a standard graphical frontend for YUM.
Yum -updates
From Fedora Core 6 there is the service yum - updatesd. This is a daemon which periodically checks for updates and, if they are available, this information can be output through different channels. Possible outputs are via email, syslog or D-Bus. There are applets that indicate when updates are available.