This a a one line command to enter in terminal,
What is a terminal and how do I open and use it?
To use it you would paste the entire command in the terminal:
wget -qO - http://deb.opera.com/archive.key | sudo apt-key add -
But of course it is daunting just copying and pasting commands without knowing what they are doing an having no instructions on how to undo their actions.
Here is a basic breakdown of the commands,
wget http://linux.die.net/man/1/wget , so this is a command to download something from a server.
| is a pipline, which takes the output of a command and runs it through another
apt-key add adds a key
So it basically downloads the key and then adds it in one command.
I tested the command and it should work.
Now to verify that it worked do from this answer http://askubuntu.com/a/107189/47291-
This will list the keys added and the key from opera should be listed on the bottom looking like this:
pub 1024D/30C18A2B 2012-10-29 [expires: 2014-10-29]
uid Opera Software Archive Automatic Signing Key 2013 <email@example.com>
sub 4096g/C528FCA9 2012-10-29 [expires: 2014-10-29]
Also I that other answer it shows that you can remove the key if needed, using:
sudo apt-key del 30C18A2B
Using the key-id listed from
After performing that command, and setting up the sources exactly like your screen-shot here: Adding repository
sudo apt-get update
sudo apt-get install opera
(note there are some random warnings, but nothing that affected the install or operation of software center)
And for the removal (just in case): What is the correct way to completely remove an application?
So check list:
- Add repository
- Add key with command
- Install in terminal
- Search in dash