How can I add a repository in a more useful way?

Question

I try to install VirtualBox in ubuntu 18.04, following https://www.virtualbox.org/wiki/Linux_Downloads

Add the following line to your /etc/apt/sources.list. According to your distribution, replace '' with 'artful', 'zesty', 'yakkety', 'xenial', 'trusty', 'stretch', 'jessie', or 'wheezy' (older versions of VirtualBox supported different distributions):

deb https://download.virtualbox.org/virtualbox/debian <mydist> contrib

1. Here is my command:

   sudo echo "deb https://download.virtualbox.org/virtualbox/debian bionic contrib" | sudo tee -a /etc/apt/sources.list
   

   Is there some programitcal way to get the value of <mydist> instead of filling bionic in? I want to make it reusable for all Ubuntu versions.

2. Also if I add the line to an individual file instead of /etc/apt/sources.list, how shall I name the file?

   • Do I need to make the filename unique so that I will not overwrite an existing file? Ho?

   • The purpose of individual file is for scripting to check existence of a repository or remove an existing repository. So is it correct that an arbitrary filename isn't okay? For example:

     echo "deb https://download.virtualbox.org/virtualbox/debian bionic contrib" > /etc/apt/sources.list.d/my.virtualbox.list
     

Thanks.

Answer 1

1. On Ubuntu, lsb_release -sc will give you the codename corresponding to the installed release.

2. If you use a filename which is already in use, and the > redirection operator, you will overwrite the existing file, yes.

   For single-line repository descriptors, filenames must end with .list. See the sources.list manpage for details. Apart from that you can use any name you like, as long as it uses only alphanumeric characters, underscores, hyphens, and periods. If you want to check for a file’s existence, you know the name you want to use; there’s no official registry of repository filenames.