What exactly is sudo bang bang?

alestanis picture alestanis · Feb 28, 2013 · Viewed 21.8k times · Source

What is the purpose of sudo bang bang (sudo !!) and when might one need to use it?

make me a sandwich, sudo bang bang

Answer

alestanis picture alestanis · Feb 28, 2013

The bang bang (!!) command is a shortcut to repeat the previous command you entered in your terminal. This command is very useful when you forget that you need admin rights to make a certain action, and lets you repeat it with super-user rights just by typing

sudo !!

instead of typing arrow-up, scrolling to the beginning of the line, adding sudo and hitting enter (imagine scrolling through those loooong apt-get commands). So many seconds gained! Yay!

sudo bang bang

There are many other bang-commands such as !x, !?x, !!:p and !!*. This blog post lists them and explains what they are for.