The sources.list is the file that tells your Debian/Ubuntu where to search for software.

## File Description

The file is located in /etc/apt/sources.list , or might be split in multiple files stored in /etc/apt/sources.list.d/ . The format is

TYPE LOCATION DIST COMPONENTS


The definition for these sections are:

TYPE
deb or deb-src
LOCATION
DIST
Distribution you are using
COMPONENTS
List of components

An example of such an entry is:

deb http://ftp.de.debian.org/debian/ sid main contrib restricted universe multiverse non-free


The tools apt-get|aptitude|synaptic|SoftwareCenter (or whatever you like to install software) will look at these files to search for updates and new packages.

## Some entries for Debian unstable

Here are some entries from my configuration that might be of interest. I’m using Debian:unstable.

#### Aptosid

Aptosid is a Debian fork, based on unstable:

#### GRML

GRML is based on Debian:unstable, and comes with some special tools for sysadmins and text tools users:

#### Opera

If you want to use Opera:

#### R

For those of you interested in the GNU R-Project:

#### my repository

Not sure if anybody but me cares about it..

## NO_PUBKEY

For some repository you need to have special GPG keys in your keyring, otherwise you’ll see an error such as:

In that case you can usually add these keys to your keyring by executing the following to command:

Just replace the contents of the \$key variable with the corresponding key id.