Ubuntu apt-get & apt-cache commands

Apt-get & apt-cache are the command line package management utility in Ubuntu Linux. GUI version of apt-get command is the Synaptic Package Manager, in this post we are going to discuss 15 different examples of apt-get & apt-cache commands.

Example:1 List of all the available packages

ubuntu@localhost:~$ apt-cache pkgnames

account-plugin-yahoojp

ceph-fuse

dvd+rw-tools

e3

gnome-commander-data

grub-gfxpayload-lists

gweled

.......................................

Example:2 Search Packages using keywords

This command is very helpful when you are not sure about package name , just enter the keyword and apt-get command will list packages related to the keyword.

ubuntu@localhost:~$ apt-cache search "web server"

apache2 - Apache HTTP Server

apache2-bin - Apache HTTP Server (binary files and modules)

apache2-data - Apache HTTP Server (common files)

apache2-dbg - Apache debugging symbols

apache2-dev - Apache HTTP Server (development headers)

apache2-doc - Apache HTTP Server (on-site documentation)

apache2-utils - Apache HTTP Server (utility programs for web servers)

......................................................................

Note: If you have installed “apt-file” package then we can also search the package using config files as shown below :

ubuntu@localhost:~$ apt-file search nagios.cfg

ganglia-nagios-bridge: /usr/share/doc/ganglia-nagios-bridge/nagios.cfg

nagios3-common: /etc/nagios3/nagios.cfg

nagios3-common: /usr/share/doc/nagios3-common/examples/nagios.cfg.gz

pnp4nagios-bin: /etc/pnp4nagios/nagios.cfg

pnp4nagios-bin: /usr/share/doc/pnp4nagios/examples/nagios.cfg

Example:3 Display the basic information of Specific package.

ubuntu@localhost:~$ apt-cache show postfix

Package: postfix

Priority: optional

Section: mail

Installed-Size: 3524

Maintainer: LaMont Jones <lamont@debian.org>

Architecture: amd64

Version: 2.11.1-1

Replaces: mail-transport-agent

Provides: default-mta, mail-transport-agent

.....................................................

Example:4 List the dependency of Package.

ubuntu@localhost:~$ apt-cache depends postfix

postfix

 Depends: libc6

 Depends: libdb5.3

 Depends: libsasl2-2

 Depends: libsqlite3-0

 Depends: libssl1.0.0

 |Depends: debconf

 Depends: <debconf-2.0>

 cdebconf

 debconf

 Depends: netbase

 Depends: adduser

 Depends: dpkg

............................................

Example:5 Display the Cache Statistics using apt-cache.

ubuntu@localhost:~$ apt-cache stats

Total package names: 60877 (1,218 k)

Total package structures: 102824 (5,758 k)

 Normal packages: 71285

 Pure virtual packages: 1102

 Single virtual packages: 9151

 Mixed virtual packages: 1827

 Missing: 19459

Total distinct versions: 74913 (5,394 k)

Total distinct descriptions: 93792 (2,251 k)

Total dependencies: 573443 (16.1 M)

Total ver/file relations: 78007 (1,872 k)

Total Desc/File relations: 93792 (2,251 k)

Total Provides mappings: 16583 (332 k)

Total globbed strings: 171 (2,263 )

Total dependency version space: 2,665 k

Total slack space: 37.3 k

Total space accounted for: 29.5 M

Example:6 Update the package repository using “apt-get update”

Using the command “apt-get update” , we can resynchronize the package index files from their sources repository. Package index are retrieved from the file located at “/etc/apt/sources.list”

ubuntu@localhost:~$ sudo apt-get update

 Ign http://extras.ubuntu.com utopic InRelease

 Hit http://extras.ubuntu.com utopic Release.gpg

 Hit http://extras.ubuntu.com utopic Release

 Hit http://extras.ubuntu.com utopic/main Sources

 Hit http://extras.ubuntu.com utopic/main amd64 Packages

 Hit http://extras.ubuntu.com utopic/main i386 Packages

 Ign http://in.archive.ubuntu.com utopic InRelease

 Ign http://in.archive.ubuntu.com utopic-updates InRelease

 Ign http://in.archive.ubuntu.com utopic-backports InRelease

 ................................................................

Example:7 Install a package using apt-get command.

ubuntu@localhost:~$ sudo apt-get install icinga

In the above example we are installing a package named “icinga”

Example:8 Upgrade all the Installed Packages

ubuntu@localhost:~$ sudo apt-get upgrade

Example:9 Upgrade a Particular Package.

“install” option along with “–only-upgrade” in apt-get command is used to upgrade a particular package , example is shown below :

ubuntu@localhost:~$ sudo apt-get install filezilla --only-upgrade

Example:10 Removing a package using apt-get command.

ubuntu@localhost:~$ sudo apt-get remove skype

Above command will remove or delete the skype package only , if you want to delete its config files then use the “purge” option in the apt-get command. Example is shown below :

ubuntu@localhost:~$ sudo apt-get purge skype

We can also use the combination of above commands :

ubuntu@localhost:~$ sudo apt-get remove --purge skype

Example:11 Download the package in the Current Working Directory

ubuntu@localhost:~$ sudo apt-get download icinga

Get:1 http://in.archive.ubuntu.com/ubuntu/ utopic/universe icinga amd64 1.11.6-1build1 [1,474 B]

Fetched 1,474 B in 1s (1,363 B/s)

Above command will download icinga package in your current working directory.

Example:12 Clear disk Space used by retrieved package files.

ubuntu@localhost:~$ sudo apt-get clean

Above Command will clear the disk space used by apt-get command while retrieving(download) packages.

We can also use “autoclean” option in place of “clean“, the main difference between them is that autoclean removes package files that can no longer be downloaded, and are largely useless.

ubuntu@localhost:~$ sudo apt-get autoclean

Reading package lists... Done

Building dependency tree

Reading state information... Done

Example:13 Remove Packages using “autoremove” option.

When we use “autoremove” option with apt-get command , then it will remove the packages that were installed to satisfy the dependency of other packages and are now no longer needed or used.

ubuntu@localhost:~$ sudo apt-get autoremove icinga

Example:14 Display Changelog of a Package.

ubuntu@localhost:~$ sudo apt-get changelog apache2

Get:1 Changelog for apache2 (http://changelogs.ubuntu.com/changelogs/pool/main/a/apache2/apache2_2.4.10-1ubuntu1/changelog) [195 kB]

Fetched 195 kB in 3s (60.9 kB/s)

Above Command will download the changelog of apache2 package and will display through sensible-pager on your screen.

Example:15 List broken dependencies using “check” option

ubuntu@localhost:~$ sudo apt-get check

Reading package lists... Done

Building dependency tree

Reading state information... Done