apt-get package management
to list all packages installed locally...
dpkg --get-selections | grep -v deinstall
To update apt-get...
sudo apt-get update
To install somethink...
sudo apt-get install unzip
To check if any packages need to be updated....
sudo apt-get -u upgrade --assume-no
(If you leave off the
--assume-no then it will prompt you to upgrade, and will default to Y)
To upgrade packages
sudo apt-get upgrade
Do you want to continue [Y/n]
The capital 'Y' means it is the default. So for 'Yes' just press enter.
If your machine says something like:
27 packages can be updated. 14 updates are security updates.
Then you may perform an upgrade, with
sudo apt-get -u upgrade --assume-no as above.
After performing an upgrade, you may have messages like this:
The following packages have been kept back: linux-headers-generic linux-headers-virtual linux-image-virtual linux-virtual snapd ubuntu-core-launcher 0 upgraded, 0 newly installed, 0 to remove and 6 not upgraded.
What is this 'kept back' business?
It means that some of the packages were not upgraded, because their dependencies would've needed to be upgraded too.
You can either