Copy the following line:
touch note.txt && echo "some note" > note.txt
You can do this either with mark and right click > copy.
You can also highlight and then press the key combination, e.g. ctrl + c.
You don't even have to copy all the text in the box anymore.
Copied. Now paste it somewhere.
It is possible that there is something in your clipboard that you do not expect.
A big problem is that some commands are executed immediately when they are inserted into a terminal.
The command you have on your clipboard now is fortunately only an echo.
When you paste it into terminal it is executed immediately:
Just imagine what could happen if the command has root privileges because you have already used sudo.
Whenever you copy something, make sure you don't paste it immediately into your terminal
Paste it into a text file first, for example. Then you will see what you copied.
Check out https://github.com/roedesh/copyguard