Automatically answer 'Yes' when using apt-get install

Question

Is there a way to make apt-get install automatically choose "yes" upon the Do you want to continue [y/N]? confirmation dialog?

Answer 1

via the apt-get man page:

apt-get -y install [packagename]

Answer 2

To omit any confirmation request (including those regarding obligatory security checks and potentially dangerous system changes) use --force-yes:

apt-get --yes --force-yes install $something

If you want to have these settings permanent, create a file in /etc/apt/apt.conf.d/, like /etc/apt/apt.conf.d/90forceyes, with the following content:

APT::Get::Assume-Yes "true";
APT::Get::force-yes "true";

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The problem with plain --yes is, that it will ask for a manual confirmation if the package signature owner's public-key is not in the keyring, or some other impactful conditions.

Answer 3

Note that if you also want to automatically go by the default answers when an interactive prompt appears, you can use DEBIAN_FRONTEND=noninteractive

Single install:

sudo DEBIAN_FRONTEND=noninteractive apt-get -y install [packagename]

E.g.:

sudo DEBIAN_FRONTEND=noninteractive apt-get -y install postfix

All updates:

sudo DEBIAN_FRONTEND=noninteractive apt-get -y update 

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You can set up finer options with -o Dpkg::Options::="--force-confdef" and -o Dpkg::Options::="--force-confold".

Examples:

apt-get update
sudo DEBIAN_FRONTEND=noninteractive apt-get upgrade -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold"

or

apt-get -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" dist-upgrade

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Example of interactive prompt:

Interesting read: Perform an unattended installation of a Debian package

Answer 4

APT::Get::Assume-Yes "true";

APT::Get::force-yes "true";

This should at least be in /etc/apt/apt.conf and commented out. I worry Ubuntu is taking the Microsoft tack of always asking for permission.

"Are you sure?", of course I am sure, I am not a trained monkey simply typing away at the keyboard, going click happy.

Next the door will ask, "Are you sure you want to go outside?"
The oven will ask, "Are you sure you want to cook?"
The automobile will ask, "Are you sure you want to apply brakes?"
The fire extinguisher will ask, "Are you sure you want to put out the fire?"
I am sorry Dave, I can't let you do that.
HAL9000 could use a contraction but Data could not, or couldn't.

Answer 5

From the apt-get HOWTO

Use the -y switch: apt-get -y install packagename

Answer 6

apt-get -y update
apt-get -y install [package]

Answer 7

generally the options from the manual should work well

apt-get -y --force-yes install package

if it does not succeed you can try to use the yes command.

yes | apt-get -y --force-yes install package

did use this with my vagrant shell provisioning script

PS: in case you want non-interactive but with generally stating no then you can try this:

yes no | apt-get install package

Answer 8

The new (well) apt alias takes the -y (--yes) switch too:

sudo apt -y upgrade

Answer 9

If you always want the -y argument I'd advise adding the line

alias apt-get='apt-get -y' #Automatic -y argument on apt-get commands

into your .bashrc. This, as the comment explains, will automatically add the -y argument to all your apt-get commands and therefore approves all the downloads.

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NOTE: This will remain true until you revert your .bashrc and restart the shell.

Answer 10

I was looking for a way to select a non-default in a script, specifically when installing wireshark, and ended up using tmux to interact with a shell, as follows:

# Start a detached root session
sudo tmux new-session -d
# Send the command
sudo tmux send-keys "DEBIAN_FRONTEND=readline apt-get -qq install wireshark-common; exit" enter
# Wait for the tmux session to get to the interactive stage
sleep 5
# Answer the question
sudo tmux send-keys "yes" enter
# Now attach to the session so we wait for command completion
sudo tmux attach

Answer 11

Using yes is package manager independent. E.g.

yes | apt-get install curl

Answer 12

Sometimes you need the --allow-downgrades with the -y Like sudo apt upgrade -y --allow-downgrades

Because the downgrades are a possibility and the "yes" options is not enough in that cases.