Can I insert sudo via the ^ command?

Question

Sorry if this is a yes/no question.. I am reading this unix tutorial and found the following:

Repeating and Modifying the Previous Command

[..]
If you mistype leavenworth as leaveworth you can correct it with the following command: % ^leave^leaven

Unfortunately I don't have a computer to try this on, but I was wondering:

Since some commands require sudo to run, could I then write ^^sudo to "insert" sudo to the previous command?

Answer 1

I think using history completion is a much more universal way to do this

$ sudo !!

Most shells have some shortcut for the previous command. That one works in bash and zsh. There are various ways you can do substitution, but usually these are best left for removing or changing bits, if you want to expand it, just grabbing the whole thing is the simplest way. You can add whatever you like before and after the !! to expand on the previous command.

Edit: The original question was about prepending to the previous command which the above covers nicely. If you want to change something inside it as the commentor below the syntax would go like this:

$ sudo !!:s/search/replace/

...where 'search' is the string to match against and replace...well you get the idea.

Answer 2

Doesn't work for me in bash:

$ whoami
mikel
$ ^^sudo
-bash: :s^^sudo: no previous substitution

or zsh:

$ ^^sudo
$

or even tcsh, which I think invented that syntax:

% ^^sudo
No previous left hand side.

!! does the job:

$ whoami
mikel
$ sudo !!
sudo whoami
root

Answer 3

YES. You can do that. e.g. to run the ls command in /root directory, you can do that as:

$ ls
$ ^ ^sudo 

The second command will execute as "sudo ls"

Mind to it that you add one "space" after sudo, in second line.