What is the correct way to abort an operation from the sudo password prompt?

Question

Sometimes it amazes me the "little" things I don't know about Unix. For years now I have occasionally noted that I don't actually know how to deal with the sudo password prompt cleanly. Every once in a while I sudo something only to realize that I don't actually want to run the command at all. This happens rarely enough I always forget to ask but just often enough that I remember I still haven't learned the right way to abort.

Once sudo starts asking for a password it doesn't want to give up. You can't Ctrl+C it. If you give it the right password it will run the command that I've decided I want to abort. The only solution I have found is to give it wrong passwords until it gives up asking and falls back to an su prompt which actually listens to a Ctrl+C. This feels dirty to me. It's sad enough that I changed my mind about a command; not to be able to cancel it cleanly is just embarrassing.

What is the proper way to tell sudo to abort the attempt while at the password prompt?

Answer 1

What I usually do is Ctrl + Z to suspend the task, then kill %1 or even kill -9 %1 to stop:

> sudo ls
[sudo] password for user:

Ctrl + Z

[1]  +   512 Suspended                     sudo ls
> kill %1
[1]  + Suspended (tty output)        sudo ls
> kill -9 %1
[1]    Killed                        sudo ls

(In case you have more background tasks in your shell: The number you need to give after the percent sign is the one in brackets []).

Answer 2

You can do this with a Ctrl + D.