InstallingSoftware
Introduction
There are several methods to install software on Ubuntu:
Add Applications, which can be found in the Applications menu, and the System > Administration menu.
Synaptic Package Manager, which can be found in the System > Administration menu.
apt-get, which is a terminal application.
dpkg, for installing downloaded .deb files.
Add Applications, Synaptic Package Manager and apt-get are all different interfaces to APT, the Advanced Package Tool. They all use the same application database. APT in itself is a front-end to dpkg, the Debian package management system.
APT
APT maintains a list of repositories, on-line software collections. Using one of the interfaces to APT, one can search through the repositories for applications to install. The default Ubuntu repositories already contain over 10,000 applications and packages.
Adding repositories
Sometimes the default repositories are not enough. In these cases, extra repositories can be added to the APT database. You will often find information on repositories in the following format:
deb <url> <component-list>
You can add a repository in one of the following ways:
In Add Applications via Settings > Repositories > Add > Custom. Enter the supplied repository line here.
In Synaptic via the same menus as in Add Applications.
- By manually editing /etc/apt/sources.list. You will need superuser privileges for this, and please make a backup before editing. Just paste the repository line at the end of the file.
(Add something about Main, Restricted, Universe, Multiverse, free, non-free, etc.)
Dependencies
Most of the time, the functionality of an application depends on the availability of another package. When installing an application, APT will take care of also installing all dependants.
See also
http://en.wikipedia.org/wiki/Advanced_Packaging_Tool
dpkg
To install a downloaded .deb file, use the following command:
dpkg -i <filename>.deb
You will need superuser privileges to do this.