6.4.3 Unattended installation with APT

For an unattended installation, add the following line in /etc/apt/apt.conf:

     Dpkg::Options {"--force-confold";}

This equivalent to running aptitude -y install packagename or apt-get -q -y install packagename. Because this automatically answers "yes" to all prompts, it may cause problems, so use this trick with care. See apt.conf(5) and dpkg(1).

You can configure any particular packages later by following Reconfigure installed packages, Section 6.4.4.