Apt > sources.list
As part of its operation, Apt uses a file that lists the 'sources' from which packages can be obtained. This file is /etc/apt/sources.list.
The entries in this file normally follow this format:
deb http://site.example.com/debian distribution component1 component2 component3 deb-src http://site.example.com/debian distribution component1 component2 component3
Of course, the above entries are fictitious and should not be used. The first word on each line, deb or deb-src, indicates the type of archive: whether it contains binary packages (deb), that is, the pre-compiled packages that we normally use, or source packages (deb-src), which are the original program sources plus the Debian control file (.dsc) and the diff.gz containing the changes needed for packaging the program.
The 'distribution' can be either the release code name / alias (lenny, squeeze, wheezy, sid) or the release class (oldstable, stable, testing, unstable) respectively. If you mean to be tracking a release class then use the class name, if you want to track a Debian point release, use the code name.
For example, if you have a system running Debian 6.0 (Squeeze) and don't want to upgrade when Debian Wheezy releases, use 'squeeze' instead of 'stable' for the distribution. If you always want to help test the testing release, use 'testing'. If you are tracking Wheezy and want to stay with it from testing to end of life, use 'wheezy'.
Alternatively, you can use a GNOME tool to edit your sources.list file. (Menu System>Administration>Software Sources).
gksu --desktop /usr/share/applications/software-properties.desktop /usr/bin/software-properties-gtk
Example: original sources.list for Debian Squeeze
deb http://ftp.br.debian.org/debian squeeze main deb-src http://ftp.br.debian.org/debian squeeze main deb http://ftp.br.debian.org/debian squeeze-updates main deb-src http://ftp.br.debian.org/debian squeeze-updates main deb http://security.debian.org/ squeeze/updates main deb-src http://security.debian.org/ squeeze/updates main
If you also want the contrib and non-free components, add contrib non-free after main.
Replace br with the appropriate country code for a mirror near you.
If you'd rather use your CD-ROM for installing packages or updating your system automatically with APT, you can put it in your /etc/apt/sources.list. To do so, you can use the apt-cdrom program like this:
# apt-cdrom add
with the Debian CD-ROM in the drive.
You can use -d for the directory of the CD-ROM mount point or add a non-CD mount point (i.e. a USB keydrive).
sources.list(5) man page
A list of UnofficialRepositories to get extra software ( Skype, Opera, Google )