I often install packages and updates for them, although sometimes it is not convenient to do a reboot if one of the packages needs it, so is there any way of telling BEFORE installing the package/update whether or not it will require you to do a reboot? I have already looked here and the solutions there don't solve my problem, nor the more or less same one described there.
1 Answer
There's no flag of sorts on packages that indicate that a reboot is required if the package is installed or updated. So, short answer: you can't.
However, you could extract the .deb files of the package before installing or updating to see if a reboot notification is made in the DEBIAN/postinst script. For example, the postinst script in the linux-image-*.deb packages execute the /usr/share/update-notifier/notify-reboot-required script, which in turn creates the /var/run/reboot-required file. Other postinst scripts may use the same method to indicate a necessary reboot, but there's no enforcement of a default method of getting to the creation of the /var/run/reboot-required file. It might be that a package is maintained by someone who isn't really into doing things like other maintainers do, and decides that the reboot notification can also be done in another script, like DEBIAN/preinst. So, long answer: you can, but it'll be a real nightmare to implement and maintain a way to detect all possible reboot notifications.
