Apt-get no confirmation on Debian and Ubuntu Linux

How can I tell apt-get to install everything to the question “Do you want to continue [y/N]?”? How do I make apt-get install answer always “Yes” to apt-get in scripts?

You can force yes to prompts. In other words assume “yes” as answer to all prompts and run non-interactively.

Automatically answer “Yes” when using apt-get install command

The syntax is:

apt-get -y install foo
apt-get -y remove bar
apt-get --yes install htop
apt-get --assume-yes foo

Force automatic “no” to all prompts for apt/apt-get command

Oppsite of above

apt-get --assume-no install pkg1
apt-get --assume-no --purge autoremove 

Forceful yes

We can do force yes too. However, this is a dangerous option that will cause apt/apt-get to continue without prompting if it is doing something potentially harmful. So I won’t recommend it until and unless you know what you are doing:

apt-get -y --force-yes install package1
apt-get -y --force-yes remove package2

apt-get DEBIAN_FRONTEND environment variable

From Explain DEBIAN_FRONTEND apt-get variable for Ubuntu / Debian:

We can use this mode when you need zero interaction while installing or upgrading the system via apt. It accepts the default answer for all questions. It might mail an error message to the root user, but that’s it all. Otherwise, it is totally silent and humble, a perfect frontend for automatic installs. One can use such mode in Dockerfile, shell scripts, cloud-init script, and more.

export DEBIAN_FRONTEND=noninteractive
apt-get -y update
apt-get -y upgrade
apt-get -y install bar

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