Adding Ubuntu Repositories

As you might imagine, you can install more Ubuntu software after installating Ubuntu. You are not even limited to the Ubuntu repositories that are initially listed.

The initial Ubuntu repositories are meant to get you started; they do not contain the location of every possible piece of software available. Rather, the initial list of repositories is enough for most Ubuntu users. It is restricted to Ubuntu software that has been tried and proven, that is supported by the Ubuntu community, and that is known not to violate copyright laws anywhere in the world.

But sometimes, you may want to add something that is not supported by Ubuntu. If someone lives in an area that has different copyright laws, those citizens may legally use software that other users may not. So it is helpful to be able to add or change the repositories that Ubuntu uses.

Superuser (Root) Access

To do this, you need superuser access. For this tutorial, I use "gksudo". If you are comfortable with the terminal (Applications ⇒ Accessories ⇒ Terminal), you can use "sudo" to affect the same thing.

Make a Backup!

Before changing the repository, you should be sure to make a backup copy of the original. Press Alt-F2 and type;

gksudo cp /etc/apt/sources.list /etc/apt/sources.list_original

The New List of Ubuntu Repositories

Next, you need to replace or add to the current list with another. First, gain root access for editing the file "sources.list". Press Alt-F2 and type:

gksudo gedit /etc/apt/sources.list

Next, save the file and close the editor.

Getting Synaptic to Download the New Ubuntu Software

Start Synaptic by selecting, from the top toolbar, System ⇒ Administration ⇒ Synaptic Package Manager. You may be asked for the appropriate superuser password again.

When Synaptic starts, click on "Reload". A window will then popup to show the system's progress in locating and downloading the directory listings of the Ubuntu repositories. When it is done, you will have access to the Ubuntu software of those repositories for installation.