When installing applications and programs on Linux there are several ways to do it. More advanced users can choose to download the source code from the developer’s website and compile it directly on their computer. Something very slow and impractical really. The most inexperienced users usually choose the easy way: search and download the binary (for example, the deb) and install it, from the package manager, by double clicking. As in Windows. And, thirdly, we have intermediate users who seek comfort and ease and make use of Linux repositories to download, install and update their programs.
What are Linux repositories?
Repositories are one of the best features that Linux has. A repository is a list of programs, usually always updated, that allows us to easily search and download all kinds of programs and tools in our distribution.
Thanks to the repositories we will be able to have a safe and reliable place from which to download software and the latest updates of all our programs. These programs will be installed without any dependency problems, and we can also update our entire program repertoire with a simple command.
The developers of the distros usually include their own repositories with useful programs. In addition, many developers maintain their own independent repositories to distribute their programs. Even any user can create and maintain their own repository, very useful, for example, to distribute software lists.
Different types of repositories in Ubuntu
When we install Ubuntu, the distro installs a series of repositories belonging to different channels:
- Main: the repository installed by default. It consists of free FOSS software that can be distributed freely and without restrictions.
- Universe: includes free and open source software, but cannot guarantee regular security updates.
- Multiverse: includes software that is from the FOSS. It must be the user who analyzes the licenses and decides whether or not to use these programs legally.
- Restricted: within this channel we can find closed source software. It is used, for example, to distribute NVIDIA drivers, among many others.
- Partner: includes proprietary software that has been packaged by Canonical.
And in addition to these repositories, we can also add third-party repositories to our Linux distro to install other software safely.
The steps we are going to see next have been done on Ubuntu, but they should be the same for any Debian-based distro.
How to add new repositories to the software list
To see the list of repositories that we have in our Ubuntu distro, what we must do is open a Terminal (Control + Alt + T) and execute the following command in this:
sudo gedit /etc/apt/sources.list
In case it does not work, or we do not have gedit installed in our distro, we can do it with the following, by going to the “nano” editor.
sudo nano /etc/apt/sources.list
As we will see, we will open a list with all the repositories that we have in our distro. Repositories (for example, deb http://en.archive.ubuntu.com/ubuntu/ bionic-updates main restricted) that start without # are those that are being used. On the other hand, those that appear at the beginning with a # are those that we have installed, but they are disabled.
If we want to add a new repo, we just have to add it, as follows, to the end of the text file:
- deb [arch = amd64] http://dl.google.com/linux/chrome/deb/ stable main
We save the changes and go. Of course, before updating the repositories and installing any program we must install the security keys of that repository. These are usually offered together with the PPA, and then we will see an example with the official Google Chrome repo.
Example to add Google Chrome repository from Terminal
To add a repository, or PPA, from Linux , we must do it as follows. The first thing will be to search the Internet for the repository we want to add. In the case of Google Chrome (this example), we can find it on the Google website .
In the terminal, we will execute the following command to add the keys of the official Google repositories to our Linux. Otherwise, the repositories software cannot be validated and will return an error:
wget -q -O – https://dl.google.com/linux/linux_signing_key.pub | sudo apt-key add –
Once the previous command has been executed, we can add the repository to the list of Ubuntu repositories. And we will do that with the following command:
sudo sh -c ‘echo “deb [arch = amd64] http://dl.google.com/linux/chrome/deb/ stable main” >> /etc/apt/sources.list.d/google.list’
Obviously, if we have added the repository from GEDIT as we explained in the previous step, this last command will not be necessary.
Now, first of all, we will have to update the list of Linux repositories to register in our system all the programs and to be able to download and install them with apt install.
How to update the list of Linux repositories
If we have already added the repositories we want to the list with the previous steps, or we simply want to update our software without adding new repositories, the process is much faster.
All we have left to do is open a Terminal (Control + Alt + T) in our Linux and execute the following two commands:
- sudo apt update (to update the software lists of the repositories).
- sudo apt upgrade (to download available packages).
When the process is finished, all the programs of our Linux, which have been installed through the repositories, will have been updated to their latest version.
We can now install the programs we want from the repositories of our Linux using apt install (for example: sudo apt install google-chrome).
