Linux Operating System: Package Management

Package management

In this short series, we'll go over package management - an essential tool for both beginner Linux users and the more seasoned system adminstrators. Package management will help you seamlessly install, upgrade and maintain software. This series will cover Debian (Ubuntu) package management for now, but we will also include lessons for Red Hat in a future lesson.

A time before package management

Long ago when software wasn't as abundant as it is today, package management was nonexistent. This meant that users had to individually download and compile source code when installing software, a process that was redundant as it was time consuming. Additionally, software that required other dependencies had to be installed separately, making the process of installing large software systems incredibly tedious. With the number of software in a person's computer increasing, so did their complexity of management, as upgrading systems had to be performed manually.

Nowadays, almost all platforms come with a designated package management system. Package managements allow you to install, upgrade, configure and remove software packages from your computer's system. At the heart of this system is a database that contains information about your softwares' last-upgrade dates, dependencies, version number, and more. Package managers allow you to conveniently manage all the software without a sweat.

How package management changed the development community

Not only has package management allowed for users to easily download and maintain software, but it has also forced developers to uphold a strict convention as to how their software is structured.

Furthermore, we now have software available in packages, with information about dependencies, and version numbers. This allows us to keep track of bug information and whether it is necessary to download security patches.

What Package Managerment software is available?

Depending on your Linux distribution, (Debian, Red Hat or SUSE), or platform (OS X), we have different package management software and tools.

Red Hat, which includes CentOS, Fedora, Mandrivia and OpenSuSE, use packaging tools rpm and yum.

For OS X, you can use Homebrew.

Review of some terminology before we begin

Package file

From the perspective of a package management system, a package file contains all the data files and programs that support the software. This is where all the metadata is found, including a description of its contents, version number and more. This also includes scripts that run before and after the installion is performed.

Dependencies

Dependencies are additional packages required by the principal package in order to function propertly. In short, it is a piece of software that is required for another to run. For example, if the year were 2004 and I wanted to watch a funny animation on the web, I would have to first install Adobe Flash Player. Thus, Adobe Flash Player serves as a dependency to flash animation videos.

Package managers maintain dependency information, allowing the system to know whether it needs to pull anything other programs in.

Libraries

Libraries are software components that can be shared by many different programs. This allows a reduction in disk space and memory requirements, as multiple programs are allowed to access the same files.

Checksums

The package management system uses checksums to validate and verify installed software. Checksums allows the computer to check for disk errors or accidental overwrites of files.

Sign in a root

To use any commands that have to deal with package management, you'll need to be signed in as root. To do so, use the sudo -s command, and put in your system's password when prompted.

Debian (Ubuntu) Package Management dpkg

The Debian package management system works on packages with the .deb extension. The main commands are dpkg, apt-get, apt-cache and aptitude. aptitude is a text-user interface for apt-get which we won't cover here.

Let's begin by going over dpkg, which is mainly used to install, dissect and extract information about packages with the .deb extension.

Dissecting your packages with dpkg

To see a complete listing of all dpkg commands and options, use the --help option. Here are the actions (and some options) that go along with dpkg:

-i|--install

Install a debian package file.

Use -E or --skip-same-version to avoid installing the package if same version is already present.

Use -G to avoid installing if newer version of package already exists.

Use --recursive to install all packages that match the package name wildcard.

Use --no-act to check for dependencies, conflicts and other problems without actually installing.

-c|--contents

List contents of a debian package file.

--configure

Reconfigure an installed package that has been unpacked.

-P|--purge

Purges an installed package (removing config files as well).

-r|--remove

Uninstall a package (does not remove config files).

Use --no-act to check for dependencies, conflicts and other problems without actually installing.

Use -B or --auto-deconfigure to disable packages that depend on the one being removed.

-s|--status

Shows information and status on the installed package.

-p|--print-avail

Print available status details

-I|--info

Extract package information.

-l|--list

List all packages on your system. Can add a pattern after the action to list matching installed packages.

-L|--listfiles

Lists all files installed (or "owned") by the package.

-C|--audit

Searches for partially installed packages and suggests what to do.

-S|--search

Searches which packages installed a file. Place the name or pattern of the package as an argument after this option.

Additionally, here are some options you may use with one of the above actions.

--ignore-depend

Ignores the dependency package.

--force-depends

Force installation without dependency.

--force-conflicts

Overcome conflict problems.

6 examples with dpkg

For practice with the dpkg command, let's try installing the Vim package and testing out or dpkg command. Here are just select 6 things you can do with with dpkg on packages.

1) List information

To print out information about our package, use the -I or --info option.

$ dpkg --info vim_7.4.488-7_amd64.deb
new debian package, version 2.0.
size 952572 bytes: control archive=2080 bytes.
 935 bytes,    22 lines      control              
 237 bytes,     4 lines      md5sums              
2471 bytes,    78 lines   *  postinst             #!/bin/sh
1218 bytes,    57 lines   *  prerm                #!/bin/sh
Package: vim
Version: 2:7.4.488-7
Architecture: amd64
Maintainer: Debian Vim Maintainers <pkg-vim-maintainers@lists.alioth.debian.org>
Installed-Size: 2233
Depends: vim-common (= 2:7.4.488-7), vim-runtime (= 2:7.4.488-7), 
libacl1 (>= 2.2.51-8), libc6 (>= 2.15), libgpm2 (>= 1.20.4), libselinux1 (>= 1.32), libtinfo5
Suggests: ctags, vim-doc, vim-scripts
Provides: editor
Section: editors
Priority: optional
Homepage: http://www.vim.org/
Description: Vi IMproved - enhanced vi editor
Vim is an almost compatible version of the UNIX editor Vi.
.
Many new features have been added: multi level undo, syntax
highlighting, command line history, on-line help, filename
completion, block operations, folding, Unicode support, etc.
.
This package contains a version of vim compiled with a rather
standard set of features.  This package does not provide a GUI
version of Vim.  See the other vim-* packages if you need more
(or less).

2) List file contents

To check the package file contents, use the -c option.

$ dpkg -c vim_7.4.488-7_amd64.deb
drwxr-xr-x root/root         0 2015-03-31 16:37 ./
drwxr-xr-x root/root         0 2015-03-31 16:37 ./usr/
drwxr-xr-x root/root         0 2015-03-31 16:37 ./usr/bin/
-rwxr-xr-x root/root   2240936 2015-03-31 16:37 ./usr/bin/vim.basic
drwxr-xr-x root/root         0 2015-03-31 16:37 ./usr/share/
drwxr-xr-x root/root         0 2015-03-31 16:37 ./usr/share/bug/
drwxr-xr-x root/root         0 2015-03-31 16:37 ./usr/share/bug/vim/
-rw-r--r-- root/root       516 2014-10-22 18:01 ./usr/share/bug/vim/presubj
-rwxr-xr-x root/root       204 2014-10-22 18:01 ./usr/share/bug/vim/script
drwxr-xr-x root/root         0 2015-03-31 16:37 ./usr/share/doc/
drwxr-xr-x root/root         0 2015-03-31 16:37 ./usr/share/lintian/
drwxr-xr-x root/root         0 2015-03-31 16:37 ./usr/share/lintian/overrides/
-rw-r--r-- root/root       138 2015-03-31 16:37 ./usr/share/lintian/overrides/vim
lrwxrwxrwx root/root         0 2015-03-31 16:37 ./usr/share/doc/vim -> vim-common

3) Unpacking and Configuring

To unpack the package, use the --unpack option. This won't configure any settings, so we must apply the --configure option along with it.

$ dpkg --unpack vim_7.4.488-7_amd64.deb
(Reading database ... 166563 files and directories currently installed.)
Preparing to unpack vim_7.4.488-7_amd64 (1).deb ...
Unpacking vim (2:7.4.488-7) over (2:7.4.052-1ubuntu3) ...

When you run with the --configure option, you may get some dependency issues, with the terminal erroring out and saying that the versions don't match up. We can handle these dependency installations easily by using apt-get command. We'll study these in the next lesson, but for now, use the following command to automatically pull in any necessary dependencies and install vim.

$ sudo apt-get install vim

4) Checking the location of package

To check where the folders that your package or software is located, use the -L option.

$ dpkg -L vim
/.
/usr
/usr/bin
/usr/bin/vim.basic
/usr/share
/usr/share/lintian
/usr/share/lintian/overrides
/usr/share/lintian/overrides/vim
/usr/share/bug
/usr/share/bug/vim
/usr/share/bug/vim/presubj
/usr/share/bug/vim/script
/usr/share/doc
/usr/share/doc/vim

5) Removing and Uninstalling

Use the -r or --remove option to remove Vim from our system, but keep the configuration files. To check if a package is installed or not, use the -s option.

$ dpkg -r vim
# Vim is now removed
$ dpkg -s vim
dpkg-query: package 'vim' is not installed and no information is available
Use dpkg --info (= dpkg-deb --info) to examine archive files,
and dpkg --contents (= dpkg-deb --contents) to list their contents.

To remove configuration files as well, we must use the -P or --purge option.

6) Listing out all packages

To list out all your packages on your system with the -l option. There's going to be a good amount of output, so consider piping to grep.

$ dpkg -l | grep vim
ii  vim                                                   2:7.4.    | 052-1ubuntu3                                  amd64        Vi IMproved - enhanced vi editor
ii  vim-common                                            2:7.4.    | 052-1ubuntu3                                  amd64        Vi IMproved - Common files
ii  vim-runtime                                           2:7.4.    | 052-1ubuntu3                                  all          Vi IMproved - Runtime files
ii  vim-tiny                                              2:7.4.052-1ubuntu3                                  amd64        Vi IMproved - enhanced vi editor - compact version
r

View log files

To see a list of the previously run dpkg commands, look at the /var/log/dpkg.log file. The tail command shows a select few lines at the bottom of the file.

$ tail /var/log/dpkg.log
2015-09-14 13:49:12 startup archives unpack
2015-09-14 13:49:14 install vim:amd64 <none> 2:7.4.052-1ubuntu3
2015-09-14 13:49:14 status half-installed vim:amd64 2:7.4.052-1ubuntu3
2015-09-14 13:49:14 status unpacked vim:amd64 2:7.4.052-1ubuntu3
2015-09-14 13:49:14 status unpacked vim:amd64 2:7.4.052-1ubuntu3
2015-09-14 13:49:14 startup packages configure
2015-09-14 13:49:14 configure vim:amd64 2:7.4.052-1ubuntu3 <none>
2015-09-14 13:49:14 status unpacked vim:amd64 2:7.4.052-1ubuntu3
2015-09-14 13:49:14 status half-configured vim:amd64 2:7.4.052-1ubuntu3
2015-09-14 13:49:14 status installed vim:amd64 2:7.4.052-1ubuntu3

Reconfiguring a package back to default

In case you altered the default configurations of a package and want to revert back, simply use the dpkg-reconfigure command, followed by the package name.

Limitations of dpkg

The main limitation of the dpkg command is that it does not automatically pull in any dependencies. The commands that are able to link and pull the relevant dependencies are apt-get and apt-cache, which we'll see next.

Installing, removing and updating with Advanced Package Tool apt-get, apt-cache

The Advanced Package Tool (APT) is a suite of commands that allow us to interface with our package management system. With it, we can install new software packages (straight from the web via terminal) and upgrade existing ones. Additionally, the apt-get command pulls in any dependencies necessary, which covers dpkg's drawback. When dealing with installing and updating software, you'll mostly be working with these commands.

Again, make sure you're signed in as root permissions with the sudo -s command.

Let's start with a moo:

# apt-get moo
                 (__) 
                 (oo) 
           /------\/ 
          / |    ||   
         *  /\---/\ 
            ~~   ~~   
..."Have you mooed today?"...

Actions with apt-get

Here is a list of actions you can use with the apt-get command.

install

Installs a package.

remove

Removes a package.

source

Retrieves newest available source package file by name.

check

Checks for consistency and if there are any broken packages.

clean

Clears out data regarding files from the Debian package database. Run this from time to time to save disk space.

update

Resynchronizes the package index files from sources. Allows for new and updated information about packages.

upgrade

Upgrade all packages to the newest version from sources in /etc/apt/sources.list.

dist-upgrade

Intelligently handles changing dependencies with new version of packages. Avoids dependency breaking.

Examples with apt

Okay, now let's get down to business! Here are 14 ways you can use the apt tool to manage your packages.

1) Refreshing your cache

You may have wondered during the previous lesson how apt-get knows where to look for Vim when we typed apt-get install vim. The answer to this question lies in the system's cache. This is where all the software package names are linked to their location on the Debian packaging server. A list of where important packages can be obtained lies in /etc/apt/sources.list. Since the Debian package management system performs automatic updates via the links in this file, it's advisable to not add any repositories unless you're sure that it may be trusted.

To update the cache on your local system, use the apt-get update command. This will make sure your current listing is up-to-date so you can download the latest packages.

# apt-get update
Ign http://security.ubuntu.com trusty-security InRelease
Ign http://extras.ubuntu.com trusty InRelease
...          
Ign http://us.archive.ubuntu.com trusty/restricted Translation-en_US           
Ign http://us.archive.ubuntu.com trusty/universe Translation-en_US             
Reading package lists... Done

2) Upgrading current softwares

Overtime, there will be new releases of your software, fixing bugs and adding new features. On Windows, you may have had to install and update them individually (darn you annoying Java updates!). On Linux however, you can upgrade all your software in one go:

# apt-get upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
  linux-generic-lts-vivid linux-headers-generic-lts-vivid
  linux-image-generic-lts-vivid
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.

In the above case, there were no upgrades performed, but from time to time you may see changes. Remember that you must update your package index before running this command!

3) Installing packages

To install a package, use the apt-get install command, followed by the package names. This will install any packages, along with its dependencies.

# apt-get install vim
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Suggested packages:
  ctags vim-doc vim-scripts
The following NEW packages will be installed:
  vim
0 upgraded, 1 newly installed, 0 to remove and 3 not upgraded.
Need to get 0 B/956 kB of archives.
After this operation, 2,237 kB of additional disk space will be used.
Selecting previously unselected package vim.
(Reading database ... 166549 files and directories currently installed.)
Preparing to unpack .../vim_2%3a7.4.052-1ubuntu3_amd64.deb ...
Unpacking vim (2:7.4.052-1ubuntu3) ...
Setting up vim (2:7.4.052-1ubuntu3) ...
update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/vim (vim) in auto mode
update-alternatives: using /usr/bin/vim.basic to provide /usr/bin/ex (ex) in auto mode

4) Removing packages

To remove any packages, use apt-get remove. This will remove any particular package, but not its dependencies. It will also keep the configuration files, so you can revert to your normal settings in case you install the particular software again.

# apt-get remove vim
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be REMOVED:
  vim
0 upgraded, 0 newly installed, 1 to remove and 3 not upgraded.
After this operation, 2,237 kB disk space will be freed.
Do you want to continue? [Y/n] Y
(Reading database ... 166554 files and directories currently installed.)
Removing vim (2:7.4.052-1ubuntu3) ...
update-alternatives: using /usr/bin/vim.tiny to provide /usr/bin/vi (vi) in auto mode
update-alternatives: using /usr/bin/vim.tiny to provide /usr/bin/rview (rview) in auto mode

To remove a package along with all its dependencies and config files, use the apt-get purge command. This is a combination of typing apt-get remove and apt-get clean.

5) Multiple packages

For multiple package installation and removals, separate each package name by spaces.

# apt-get install vim-nox emacs24 nanoweb

6) Removing unnecessary dependencies

To remove any packages that were downloaded and are in your cache, you may remove them with the apt-get clean command. This will free up a good amount of previously unused space.

7) Simulating installation

Sometimes you may want to simulate a run just to see what a apt-get install command would do. In this case, you can pass in the simulate option -s.

# apt-get -s install xxxterm
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
   libjavascriptcoregtk-1.0-0 libwebkitgtk-1.0-0 libwebkitgtk-1    | .0-common
The following NEW packages will be installed:
  libjavascriptcoregtk-1.0-0 libwebkitgtk-1.0-0 libwebkitgtk-1    | .0-common
  xxxterm
0 upgraded, 4 newly installed, 0 to remove and 3 not upgraded.
Inst libjavascriptcoregtk-1.0-0 (2.4.8-1ubuntu1~ubuntu14.04.1 Ubuntu:14.04/trusty-updates [amd64]) Inst libwebkitgtk-1.0-common (2.4.8-1ubuntu1~ubuntu14.04.1    | Ubuntu:14.04/trusty-updates [all]) Inst libwebkitgtk-1.0-0 (2.4.8-1ubuntu1~ubuntu14.04.1 Ubuntu:14.04/trusty-updates [amd64])
Inst xxxterm (1:1.11.3-1.2 Ubuntu:14.04/trusty [amd64]) 
Conf libjavascriptcoregtk-1.0-0 (2.4.8-1ubuntu1~ubuntu14.04.1  Ubuntu:14.04/trusty-updates [amd64])
Conf libwebkitgtk-1.0-common (2.4.8-1ubuntu1~ubuntu14.04.1 Ubuntu:14.04/trusty-updates [all]) 
Conf libwebkitgtk-1.0-0 (2.4.8-1ubuntu1~ubuntu14.04.1  Ubuntu:14.04/trusty-updates [amd64])
Conf xxxterm (1:1.11.3-1.2 Ubuntu:14.04/trusty [amd64])

Instead of actually performing any actions, you'll see parameters such as Inst and Conf, indicating where the package will be installed and configured.

8) Setting all responses to yes

To set all responses to Yes, so that you don't have to type them per each confirmation prompt, use the -y flag.

# apt-get -y remove vim

9) Download but not install

To download but not install, use the -d flag.

# apt-get -d install vim

10) Suppressing output

To suppress output, use the -qq flag. This will quietly install Vim.

# apt-get install -qq vim

11) Finding a package

The apt-cache command is used to query the package database for information. For example, if you know the name of the package, but aren't sure of the keyword, you can search the package as a query string.

To find a package, first update your cache, the run apt-cache search with your query.

# apt-get update
# apt-cache search convert wma
dir2ogg - audio file converter into ogg-vorbis format
kid3 - KDE MP3 ID3 tag editor
kid3-cli - Command line audio tag editor
kid3-core - Audio tag editor core libraries and data
kid3-qt - Audio tag editor
nautilus-script-audio-convert - A nautilus audio converter script
pacpl - multi-purpose audio converter/ripper/tagger script
sorune - tool to manage the database on the Neuros Audio player

12) Viewing package details

You can easily see package details with apt-cache show.

# apt-cache show vimPackage: vim
Priority: optional
Section: editors
Installed-Size: 2185
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Original-Maintainer: Debian Vim Maintainers <pkg-vim-maintainers@lists.alioth.debian.org>
Architecture: amd64
Version: 2:7.4.052-1ubuntu3
Provides: editor
Depends: vim-common (= 2:7.4.052-1ubuntu3), 
  vim-runtime (= 2:7.4.052-1ubuntu3), libacl1 (>= 2.2.51-8), 
  libc6 (>= 2.15), libgpm2 (>= 1.20.4), libpython2.7 (>= 2.7), 
  libselinux1 (>= 1.32), libtinfo5
Suggests: ctags, vim-doc, vim-scripts
Filename: pool/main/v/vim/vim_7.4.052-1ubuntu3_amd64.deb
Size: 955616
MD5sum: f870bba8885a240acb21977e22503c73
SHA1: 038639fda5e3a73d7f26a8e1bd20faa0282c74ff
SHA256: 1c59553660fb37a9a0317ce7a906b55d580be53e4a478c55a88da4de9f9a86b9
Description-en: Vi IMproved - enhanced vi editor
 Vim is an almost compatible version of the UNIX editor Vi.
 .
 Many new features have been added: multi level undo, syntax
 highlighting, command line history, on-line help, filename
 completion, block operations, folding, Unicode support, etc.
 .
 This package contains a version of vim compiled with a rather
 standard set of features.  This package does not provide a GUI
 version of Vim.  See the other vim-* packages if you need more
 (or less).
Description-md5: 59e8b8f7757db8b53566d5d119872de8
Homepage: http://www.vim.org/
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Origin: Ubuntu
Supported: 5y
Task: ubuntu-usb, cloud-image, server, edubuntu-desktop-gnome, edubuntu-usb

13) View package's policies

To view the current and most recent package versions, use the apt-cache policy command.

# apt-cache policy vim
vim:
  Installed: 2:7.4.052-1ubuntu3
  Candidate: 2:7.4.052-1ubuntu3
  Version table:
 *** 2:7.4.052-1ubuntu3 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status
        
h4 14) View package's dependencies
p
  | To view a package's dependencies, use the 
  code.lang-bash.single.command apt-cache showpkg
  |  command. To view any unmet dependencies, use 
  code.lang-bash.single.command apt-cache unmet
  | .
pre
# apt-cache showpkg vim
Package: vim
Versions: 
2:7.4.052-1ubuntu3 (/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_trusty_main_binary-amd64_Packages) 
(/var/lib/dpkg/status)
 Description Language: 
                 File: /var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_trusty_main_binary-amd64_Packages
                  MD5: 59e8b8f7757db8b53566d5d119872de8
 Description Language: en
                 File: /var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_trusty_main_i18n_Translation-en
                  MD5: 59e8b8f7757db8b53566d5d119872de8
 
Reverse Depends: 
  vim-syntax-docker,vim
  mercurial,vim
  exuberant-ctags,vim
  byobu,vim
  vim:i386,vim
  vimhelp-de,vim 2:7.5
  vimhelp-de,vim 2:7.4
  vim-vimoutliner,vim
  vim-syntax-go,vim
  vim-syntax-docker,vim
  vim-scripts,vim
  vim-scripts,vim
  vim-rails,vim
  vim-migemo,vim
  vim-latexsuite,vim
  vim-latexsuite,vim
  vim-gocomplete,vim
  vim-addon-manager,vim
  supercollider-vim,vim
  ocaml-tools,vim
  mercurial,vim
  libvi-quickfix-perl,vim
  libtext-vimcolor-perl,vim
  kde-developer-sdk,vim
  halibut,vim
  gworkspace-apps-wrappers,vim
  edubuntu-desktop,vim
  debian-reference-common,vim
  vim-runtime,vim
  vim-dbg,vim 2:7.4.052-1ubuntu3
  vim-common,vim
  exuberant-ctags,vim
  byobu,vim
Dependencies: 
2:7.4.052-1ubuntu3 - vim-common (5 2:7.4.052-1ubuntu3) vim-runtime (5 2:7.4.052-1ubuntu3) 
  libacl1 (2 2.2.51-8) libc6 (2 2.15) libgpm2 (2 1.20.4) 
  libpython2.7 (2 2.7) libselinux1 (2 1.32) libtinfo5 (0 (null)) 
  ctags (0 (null)) vim-doc (0 (null)) vim-scripts (0 (null)) vim:i386 (0 (null)) 
Provides: 
2:7.4.052-1ubuntu3 - editor 
Reverse Provides: 
vim-nox 2:7.4.052-1ubuntu3
vim-gtk 2:7.4.052-1ubuntu3
vim-athena 2:7.4.052-1ubuntu3
vim-gnome 2:7.4.052-1ubuntu3

Commands with aptitude

Want a more user-friendly interface to managing your packages? No problem! We can do most all commands performed with apt-get and apt-cache with the aptitude interface. This uses a menu-driven, text-based application ran within the terminal, and serves as a front-end interface to the APT tool. Most commands are run with a single, lowercase letters.

Launching aptitude

To launch aptitude, simply type aptitude. You may need to install it by typing sudo apt-get install aptitude.

Basic commands

Here is a list of the most basic commands to get you started:

?

Help

arrow keys

Navigation

+

Install/Update

-

Remove

u

Upgrade

g

Preview and confirm actions

q

Quit

a

Accept an action

r

Reject an action

Updating the cache

Simply hit the u key to update the cache.

Installing packages

1. Hover over the Not Installed Packages section.
2. Move into the folder by pressing the ENTER key.
3. Position your cursor over to the package you want and press the + key.
4. Package entry will turn green if successfully marked for installation.
5. Press g to get a list of package actions.
6. Press g again to download and install the package.

Removing packages

1. Navigate to the installed packages category by using the keyboard arrow keys and hit ENTER.
2. Highlight the desired package and press -.
3. Package entry will turn pink if it has been successfully marked for removal.
4. Press g to see a list of package actions, and press g again to remove the package.

Upgrading packages

1. Press the U key to mark all packages with updates.
2. Press g and you'll obtain a list of package actions.
3. Press g again to download and install the new updated package contents.
4. Press ENTER to return to the menu.

Package attributes

i

Installed package.

c

A package that is not installed, but its configuration is on system.

p

Purged from system.

v

Virtual package.

B

Broken package, meaning you have not installed its dependencies.

u

Unpacked files, but package not yet configured.

C

Half-configured, configuration failed and rquires to fix.

H

Half-installed, removal failed and requires fix.

Exiting

To exit the interface, press q and confirm.

Using aptitude on the command line

Aptitude can also perform several command line tasks that are identical to apt-get.

install

Install one or more packages.

update

Updates the list of available packages from apt sources.

safe-upgrade

Conservative about removing packages or installing new ones. so it may fail.

full-upgrade

Less conservative. Removes and installs packages as necessary. May break software in the process.

search

Searches database for packages matching specified name.

show

Displays detailed information about on or more packages.

clean

Removes all previously downloaded .deb files from the package cache.

autoclean

Removes already downloaded packages that are no longer available.

clean

Removes all downloaded packages.

help

Display help.

RPM Package Manager

The one other major package manager we will discuss is RPM (RPM Package Manager), which was developed by Red Hat under the General Public License. RPM is used in several distros - RedHat, Fedora, SUSE/openSUSE, and Mandriva.

Package Naming Convention

RPM files have a more stringent convention than the packages found for Debian. You may find these packages at the RPM repository or simply through the yumdownloader command. In this lesson, we'll look at installing Ninvaders, space invaders for the command line!

Firstly, we want to install the package with the following command:

# yumdownloader ninvaders      

ninvaders-0.1.1-12.fc23.x86_64.rpm

Package Name

ninvaders

The name of the package.

Version Number

0.1.1

The version number.

Build Number

12.fc23

Minor changes made not by the package author but the package maintainer. These include small tweaks in configuration files or added documentations. Here, we can also see that this was the 12th build version, made for Fedora 23.

Architecture

x86_64

The package architecture. For example, i386 would signify the CPU's from 80386 onward. Here, we have the a x86_64 architecture.

The rpm command

rpm installs, verifies and queries RPM packages. Included are actions, along with options for fine-tuning. We'll look at the most well-used options, but for a more comprehensive list, check the man page.

# rpm [action][options] [package]

Below are some general options you can use with the rpm command.

General Options

-?|--help

Print a longer usage than normal.

--version

Print out the version number of rpm.

--quiet

Print as little as possible.

Now here are five of the most commonly used actions with rpm.

1) Querying

You can verify if a package is installed with the -q option. This will print out its name, version and release name.

# rpm -q ninvaders
package ninvaders is not installed# rpm -q openssh
openssh-7.1p1-3.fc23.x86_64

Here, we can see that openssh is already installed, while ninvaders is not.

If you already know that a program is installed, tack on the -i option to check its information.

# rpm -qi openssh
Name        : openssh
Version     : 7.1p1
Release     : 3.fc23
Architecture: x86_64
Install Date: Thu 29 Oct 2015 02:23:32 PM PDT
Group       : Applications/Internet
Size        : 1586400
License     : BSD
Signature   : RSA/SHA256, Fri 25 Sep 2015 06:44:55 PM PDT, Key ID 32474cf834ec9cba
Source RPM  : openssh-7.1p1-3.fc23.src.rpm
Build Date  : Fri 25 Sep 2015 05:31:51 AM PDT
Build Host  : buildvm-14.phx2.fedoraproject.org
Relocations : (not relocatable)
Packager    : Fedora Project
Vendor      : Fedora Project
URL         : http://www.openssh.com/portable.html
Summary     : An open source implementation of SSH protocol versions 1 and 2
Description :
SSH (Secure SHell) is a program for logging into and executing
commands on a remote machine. SSH is intended to replace rlogin and
rsh, and to provide secure encrypted communications between two
untrusted hosts over an insecure network. X11 connections and
arbitrary TCP/IP ports can also be forwarded over the secure channel.
OpenSSH is OpenBSD's version of the last free version of SSH, bringing
it up to date in terms of security and features.
This package includes the core files necessary for both the OpenSSH
client and server. To make this package useful, you should also
install openssh-clients, openssh-server, or both.

To list all packages listed in your system, use:

# rpm -qa
...
libvisio-0.1.3-2.fc23.x86_64
libsysfs-2.1.0-18.fc23.x86_64
librdmacm-1.0.18.1-4.fc23.x86_64
spice-glib-0.30-1.fc23.x86_64
sssd-client-1.13.1-2.fc23.x86_64
...    

We can also query as to what dependencies a package fulfills.

# rpm -q --whatrequires openssh
openssh-clients-7.1p1-3.fc23.x86_64
openssh-askpass-7.1p1-3.fc23.x86_64
openssh-server-7.1p1-3.fc23.x86_64

2) Installing

To install a package, change into the directory that holds the .rpm file, then run with the -i option. With this, rpm will check for dependencies, conflicts, set config files, and unpack the files to place them in the right folders.

# rpm -ivh ninvaders-0.1.1-12.fc23.x86_64.rpm
Preparing...                          ################################# [100%]
Updating / installing...
1:ninvaders-0.1.1-12.fc23          ################################# [100%]

The -i option does the actual installing, while the -v option is for verbosity, and -h is to display hash marks for progression.

To specify a root folder, you may add the --root dir option. This will specify where the root directory, which is helpful if you have more than one Linux installation.

When installing, you may run into dependency issues. To force the installation, use the --force option. To not check for dependencies, use --nodeps.

Now that we've installed ninvaders, we can play it by typing nInvaders!

3) Upgrading

To upgrade a package to its most recent version, use the -U option for upgrade (or install if unavailable) or -F for freshen.

# rpm -Uvh ninvaders-0.1.1-12.fc23.x86_64.rpm     

4) Uninstalling

To uninstall a package, specify the package name (not the .rpm) file.

# rpm -e ninvaders    

Configuration files

The RPM configuration file is located in /usr/lib/rpm/rpmrc. If you want to create your own settings, edit /etc/rpmrc or set a ~/.rpmrc file within your home folder.

Notably, this file allow you to fine-tune the compilation process, according to the CPU being used.

Just like how dpkg doesn't provide you with the ability to install and manage package dependencies, rpm does not either. Instead, we can use yum, which we will discuss next.

Installing packages with dependencies yum

An easier way to install packages with their dependencies is through the yum command. This pulls in any packages from its list of known repositories. Simply specify the package you want and it'll pull in all the necessary dependecies for you and download them.

dnf has replaced the command yum since Fedora 22 versions. If you're using any Fedora versions before 22, you should read through this page - otherwise, skip to the next lesson.

Origins

The yum command originally came from the Yellow Dog Linux distribution. It was used by distros such as Fedora, SUSE and Mandriva.

Syntax

The yum command comes with actions that specify a command, and options for fine-tuning. The syntax is as follows:

# yum [options] [action] [package]

Actions

Here are a list of actions that are used with the yum command.

install

Install package and its dependencies if any are missing.

check-update

Check to see which packages have any updates available.

update

Update the specified packages, or update all if no packages are specified. Note that it's similar to apt-get upgrade.

upgrade

Delete any packages that are obsolete. Same as update with the --obsoletes flag.

remove|erase

Delete the specified package from the system, including any of its dependencies.

list

Displays information about a package - including version number and whether an update is available.

search

Search through the repository for keywords included in the package name and description. Use this to identify the exact package name when knowing just a keyword.

info

Shows information regarding a package.

clean

Clears out the yum cache directory.

localupdate

Updates system.

localinstall

Installs RPM files using Yum.

deplist

Shows a list of dependencies for a specified package.

Example Installation

Installing a package is easy as just one step! All dependencies will be pulled in automatically.

 # yum install ninvaders
Yum command has been deprecated, redirecting to '/usr/bin/dnf install ninvaders'.
See 'man dnf' and 'man yum2dnf' for more information.
To transfer transaction metadata from yum to DNF, run:
'dnf install python-dnf-plugins-extras-migrate && dnf-2 migrate'
Last metadata expiration check performed 2:10:26 ago on Mon Dec 28 12:03:27 2015.
Dependencies resolved.
=============================================================================
 Package           Arch           Version               Repository      Size
=============================================================================
Installing:
 ninvaders         x86_64         0.1.1-12.fc23         fedora          37 k
Transaction Summary
=============================================================================
Install  1 Package
Total download size: 37 k
Installed size: 87 k
Is this ok [y/N]: y
Downloading Packages:
ninvaders-0.1.1-12.fc23.x86_64.rpm            35 kB/s |  37 kB     00:01
-----------------------------------------------------------------------------
Total                                         22 kB/s |  37 kB     00:01
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Installing  : ninvaders-0.1.1-12.fc23.x86_64                           1/1
  Verifying   : ninvaders-0.1.1-12.fc23.x86_64                           1/1
Installed:
  ninvaders.x86_64 0.1.1-12.fc23
Complete!

Yum alternatives

If you need to just download a package (and not install it) you may use the yumdownloader command.

For a GUI front-end to yum, consider using kyum or yumex. You may need to install these using a yum command from above.

Configuration files

The yum configuration file lists where to find repositories as well as where all downloaded packages should go, along with access logs settings. The configuration file is located in /etc/yum.conf and the directory /etc/yum.repos.d.

Installing packages with dependencies dnf

DNF Does Not stand For anything. It was created to solve longstanding problems with yum, such as dependency resolutions and interaction with online repositories. Furthermore, Yum's API is poorly documented, and after several bouts of poorly-managed refactoring, it has become difficult to keep the program slim and well-specified.

DNF has also improved on lower memory reduction and less automatic synchronization of metadata with respositories.

Actions

Here are five subcommands that you can use with dnf.

1) General

Here are some general commands about the dnf package itself.

--version

Check the version of DNF installed.

repolist

List all enabled repositories on your system. Add all at the end to view disabled repositories as well.

list

List all available packages on the repos and installed packages.

2) Searching

# dnf search vim
...
vim-minimal.x86_64 : A minimal version of the VIM editor
...

3) Query

To get information about a package

# dnf info vim
  Name        : vim-minimal
  Arch        : x86_64
  Epoch       : 2
  Version     : 7.4.640
  Release     : 4.fc22
  Size        : 922 k
  Repo        : @System
  Summary     : A minimal version of the VIM editor
  URL         : http://www.vim.org/
  License     : Vim
  Description : VIM (VIsual editor iMproved) is an updated and improved version of the
              : vi editor.  Vi was the first real screen-based editor for UNIX, and is
              : still very popular.  VIM improves on vi by adding new features:
              : multiple windows, multi-level undo, block highlighting and more. The
              : vim-minimal package includes a minimal version of VIM, which is
              : installed into /bin/vi for use when only the root partition is
              : present. NOTE: The online help is only available when the vim-common
              : package is installed.
  
  Available Packages
  Name        : vim-minimal
  Arch        : x86_64
  Epoch       : 2
  Version     : 7.4.827
  Release     : 1.fc22
  Size        : 465 k
  Repo        : updates
  Summary     : A minimal version of the VIM editor
  URL         : http://www.vim.org/
  License     : Vim
  Description : VIM (VIsual editor iMproved) is an updated and improved version of the
              : vi editor.  Vi was the first real screen-based editor for UNIX, and is
              : still very popular.  VIM improves on vi by adding new features:
              : multiple windows, multi-level undo, block highlighting and more. The
              : vim-minimal package includes a minimal version of VIM, which is
              : installed into /bin/vi for use when only the root partition is
              : present. NOTE: The online help is only available when the vim-common
              : package is installed.

4) Installing

Instaling is similar to how it was done in yum.

# sudo dnf install vim-minimal

5) Upgrading/Updating

In dfn, upgrading and updating mean the same thing.

# Update just vim-minimal
# dnf update vim-minimal
# Update all installed software
# dnf upgrade

Converting between package formats alien

There are times you need to convert among tarbells, .rpm, and .deb. Not all software and packages are available on both platforms, so this is not uncommon. The command line tool that gets this done is the alien.

Requirements

The alien program requires that you have both RPM and Debian package manager to convert between formats. Thus, install both using the appropriate yum or apt-get commands.

# apt-get install alien
# yum install alien      

Syntax

The syntax for alien is as follows:

$ alien [options] file[...]

Options

Here are some of the commonly used options with alien.

-d|--to-deb

Convert the specified package to Debian. This option is the default.

-r|--to-rpm

Convert to RPM.

--to-slp

Convert for Stampede Linux.

--

-t|--to-tgz

Convert to a Slackware tgz package.

-i|--install

Installs the converted package, then removes it.

-k|--keep-version

Keep the version number of the generated package.

-v|--verbose

Verbose mode: display each command.

Converting rpm to deb and vice versa

As mentioned above, converting to .deb files is the default option.

# Converting to .deb
# alien packagename.rpm
# Converting to rpm
# alien -r packagename.deb