= Package management system

[[package-management-system]]
Package Management System
-------------------------

[[introduction]]
Introduction
~~~~~~~~~~~~

Fedora is a distribution that uses a package management system. This
system is based on https://rpm.org[rpm] , the RPM Package Manager, with
several higher level tools built on top of it, most notably
https://www.freedesktop.org/software/PackageKit/[PackageKit] (default
gui) and Yum (command line tool). As of Fedora 22, yum has
been replaced by xref:dnf.adoc[DNF]. The Gnome Package Manager is another
GUI package manager.

[[advantages-of-package-management-systems]]
Advantages of package management systems
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Package management systems have many advantages:

* It's easy to query what version of a package is installed or available.

* It's easy to remove a package entirely, making sure all its files are gone.

* It's easy to verify the integrity of the packages files, so you can
  see if it's been corrupted or tampered with.

* It's easy to upgrade a package by installing the new version and
  removing all the old versions files. This will make sure not to leave
  any lingering files from the old package around to confuse or break
  things.

* It's easy to see what packages require or provide things that other
  packages provide or require, so you can be sure to have the needed items
  for the package to function correctly.

* It's easy to install or remove groups of packages.

* In many cases it's possible to downgrade back to a previous version of
  a package, for example when a new version has a bug.

[[disadvantages-of-package-management-systems]]
Disadvantages of package management systems
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* You are restricted to either using the versions of the package that
  are available or having to make your own package if you need a different
  version.

[[why-mixing-source-installs-and-packages-is-a-bad-idea]]
Why mixing source installs and packages is a bad idea
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Package management systems have no way to query or note when you bypass
them and install something from source. You should avoid mixing source
installs and packaged installs for (at least) the following reasons:

* You lose all the advantages above from a package managed system.

* Installing from source may overwrite, delete, or change existing files
  that are in a package, making that package not function correctly.

* The source install may override a package install causing undefined
  behavior in the package or source installed item.

* Installing from source makes it impossible or very difficult for
  anyone to help you debug issues, since versions can't be easily queried
  and integrity checked.

* Fedora packages may include patches or configuration to work with
  other packages, but upstream source does not, leading to loss of
  functionality.

* Software installed from source will not upgrade with package managed
  packages, leading to breakage in the source install package on upgrades
  or os updates.

Strongly consider making your own package if you need a different
version or a version of some package with changes. See:
link:How_to_create_an_RPM_package[How to create a RPM package]

[[preferred-search-order-for-a-software]]
Preferred search order for a software
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If some software is missing in your installation then you should try the
following steps to get the packaged version:

1.  Search in Fedora ( 'yum|dnf search foo' or search for 'foo' in the
    PackageKit gui )
2.  Try one of the available link:Third_party_repositories[ 3rd party]
    repositories
3.  link:How_to_create_an_RPM_package[ Build your own package]

[[package-management-tools]]
Package Management tools
~~~~~~~~~~~~~~~~~~~~~~~~

xref:dnf.adoc[dnf] - Dandified Yum

https://www.freedesktop.org/software/PackageKit/[PackageKit] -
PackageKit gui tool ('add/remove software' in your menu)

https://rpm.org[rpm] - RPM package manager.

http://ww1.yum-extender.org/[yumex] - Yum Extender.

Category:Software_Management[Category:Software Management]
'''

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