如何以非交互方式安装apt软件包？
如果我跑：
sudo apt-get --yes install postfix 要么
sudo bash -c 'yes | apt-get --yes install postfix'
出现交互式提示以配置postfix。 我需要自动安装postfix（我可以在安装后修改配置文件）。
是否有一些魔法可以让我在没有人为干预的情况下安装postfix（和其他软件包）？
将DEBIAN_FRONTEND设置DEBIAN_FRONTEND noninteractive ：
DEBIAN_FRONTEND=noninteractive apt-get ...
这也适用于dpkg --reconfigure ， dpkg-configure等。
来自man 7 debconf ：
noninteractive This is the anti-frontend. It never interacts with you at all, and makes the default answers be used for all questions. It might mail error messages to root, but that's it; otherwise it is completely silent and unobtrusive, a perfect frontend for automatic installs. If you are using this front-end, and require non-default answers to questions, you will need to preseed the debconf database; see the section below on Unattended Package Installation for more details.
如果你设置了noninteractive ，你应该考虑使用debconf-set-selections来回答debconf问题。