and what's "sudo su -c dpkg --configure -a" for?
A quick breakdown for all:
sudo = SuperUser DO command. Issues a command with administrative privileges.
su = switches to another user account without needing to log out and log in, allowing a command to be issued as another user
-c = This denotes the command for the other user. Use the -c, then type the command that is to follow.
dpkg = is an installation or removal utility
--configure = this command tells dpkg to run the configuration script that will set the parameters of installed software to the existing hardware and software being installed to. For example, installing software that must make use of Graphics Drivers must be configured to know which drivers it must communicate through to run on the graphics card.
-a = All. This command denotes to perform a command for All.
Below that you will also see ''-f' which is the command "Force install". The command to install by Force is used to Force the installation of a package that your computer initially refused to install if the --configure- found missing dependencies or incompatibility. Sometimes, configuration utility is over-protective and needs a human operator to 'force' through an installation Would Work, but the Utility's programming makes it think it would not work.
In this thread, "sudo su -c dpkg --configure -a" is used in regards to a system Upgrade. As this upgrade may consist of software that makes use of existing software and hardware on your machine, it will need to be configured.
So, SuperUser Privileges first to install with Root using 'sudo', 'su' to switch from the admin account to the user account to install the upgrade to the users account (Not applicable in your case), -c to show that the command for the other user follows; the following command is for the 'dpkg' utility to '--configure" and Install (when you invoke dpkg, the command to install is automatic) the upgrade to; '-a' all user accounts.
I hope this breakdown and explanation helps. Perhaps Albano could have explained it more neatly or better than I. I have not seen Albano actively post on this forum in the entire time I have been on it.
I do not believe that the listed commands above are applicable on Ubuntu 18.04. The terminal commands given above say to run the apt updater, which updates the sources list, then gives an installation command without specifying what is to be installed until after. It tells to switch user account from Admin to User without ensuring that it is necessary to do so as many of todays users are also the Admin as they installed Zorin on their personal Home Machine.
I am not certain as I moved from Windows to Linux after all that and started out on Zorin 12, just before Zorin 15 was introduced. I have only been using Zorin and Linux for a short time and lack experience with anything at all pre-Zorin12.