======Package Management======
Is controlling software (Packages) in a Linux environment.
----
**RPM / YUM / DNF** present on:
  *Redhat
  *CentOS
  *Fedora
  *Suse

**apt-get / dpkg** present on:
  *Debian
  *Ubuntu
  *Mint

===== RPM Package Management=====
Redhat Package Manager -- now recursive -- RPM Package Manager -- after being adopted by multiple distros.

Package file naming conventions (NOT A REQUIREMENT):
  * //packagename-a.b.c-x.arch.rpm//
    * **Package Name** - name of package, like.. samba
    * **Version Number** - (a.b.c) this is the package version number like 3.6.5 -- the programmer assigns this number.
    * **Build Number** - number following version number (x) represents minor changes (patches, tweaks) made by package container.
    * **Architecture** - Defines the architecture the package was made to run on. i386 is common. there are further archs like: i586, i686, x86_64, PPC, noarch(scripts)


Operators:
  * **-i** -- Install
  * **-U** -- Upgrade if already installed
  * **-q** -- Query, get info about packages


=====DEB Based Package Management=====
----
uses apt-get / dpkg

====apt====
Config file located in ///etc/apt///sources.list important. sources.list.d folder contains official repos.
  *apt-get update -- updates repo list. DOES NOT UPGRADE.

===apt-cache===
  ***search** //thing// -- searches packages on local package cache for //thing// to download from server.
  ***stats** -- shows stats based on the metadata downloaded about our repos.
  ***depends** apache2 -- shows dependencies for the apache2 package.
  ***unmet** -- shows pkgs that have unmet depends.

  *apt-get install //apache2// - install apache2 + deps from repos.
  *apt-get upgrade -- upgrades out of date packages.
  *apt-get clean -- cleans up local pkg files, temp files, etc.
  *apt-get autoclean -- only cleans out packages that are no longer avail in our source repo. These can no longer be downloaded and are largely useless files.
  *apt-get install -s php5 -- -s says simulate install php5. useful!
  *apt-get install -y php5 -- will auto input YES on prompts.
  *apt-get install -y -q php5 -- -q omits some terminal output.
  *apt-get source php5 -- this will download the source files php5 and not the PACKAGE php5.
  * **apt-get dist-upgrade** -- RTFM, performs upgrade but also handles changing of dependencies of new versions of a package. As a result, some packages may be removed.


===== DEB =====
====apt-get====
You can edit sources in /etc/apt/sources.list
<code>
deb     http://http.debian.net/debian wheezy         main
deb-src http://http.debian.net/debian wheezy         main
deb     http://security.debian.org/   wheezy/updates main
deb-src http://security.debian.org/   wheezy/updates main
</code>
deb entries specify debian PACKAGES where as deb-src specifies SOURCE PACKAGES, upon which to compile a package/program.

Useful commands:
  *apt-get update

=====CENTOS=====
  *Uses yum/rpm.
  *Repos listed in **/etc/yum.repos.d/**

====rpm====
  *-ivh //packagefile// - Installs //packagefile// with a series of hashes as indicators.
  *-uvh - Same as -ive but upgrades a a package if already installed?
  *-q //pkgname// - Queries to see if //packagename// is installed.
  *-e //pkgname// - remove //pkgname// from system.

====yum====
  *yum makecache fast - updates local cache of repo contents. Similar to Pacman -Syy
  *yum search //name// - searches repos for pkgs named //name//
  *yum install //httpd// - installs //httpd// and deps from repos.
  *yum update -- updates all packages on system.