The apt-get command
is a powerful command-line tool, which works with Ubuntu's Advanced
Packaging Tool (APT) performing such functions as installation of new
software packages, upgrade of existing software packages, updating of the
package list index, and even upgrading the entire Ubuntu system.
Being a simple command-line
tool, apt-get has numerous advantages over other package management
tools available in Ubuntu for server administrators. Some of these advantages
include ease of use over simple terminal connections (SSH), and the ability to
be used in system administration scripts, which can in turn be automated by the cron scheduling
utility.
Some examples of popular
uses for the apt-get utility:
Install a
Package: Installation of packages
using the apt-get tool is quite simple. For example, to install the
network scanner nmap, type the following:
sudo apt-get install nmap
Remove a Package: Removal
of a package (or packages) is also straightforward. To remove the package
installed in the previous example, type the following:
sudo apt-get remove nmap
Also, adding the --purge option
to apt-get remove will remove the package configuration files as
well. This may or may not be the desired effect, so use with caution.
Update the Package Index: The
APT package index is essentially a database of available packages from the
repositories defined in the/etc/apt/sources.list file
and in the /etc/apt/sources.list.d directory. To update the local
package index with the latest changes made in the repositories, type the
following:
sudo apt-get update
Upgrade Packages: Over
time, updated versions of packages currently installed on your computer may
become available from the package repositories (for example security updates).
To upgrade your system, first update your package index as outlined above, and
then type:
sudo apt-get upgrade
Actions of the apt-get command,
such as installation and removal of packages, are logged in the
/var/log/dpkg.log log file.
For further
information about the use of APT, read the comprehensive Debian APT User
Manual or type:
apt-get help