I am working on a simple bash script that configures new servers how I want them. It's nothing special but it will hopefully save me quite a lot of time in the future.

How do I prevent prompts like this:

  You are about to add the following PPA to your system:

    Stable version of nginx.

    More info: https://launchpad.net/~nginx/+archive/stable

  Press [ENTER] to continue or ctrl-c to cancel adding it

When running commands like this from a script:

  sudo add-apt-repository ppa:nginx/stable 

  sudo apt-get update

  sudo apt-get -y install nginx

Is there an auto accept flag that I can set or something like that?