I know how check if new packages are available with root privilegies. But how can I do it from shell script without sudo or editing sudoers. I'm using Debian 12 with openbox. Thanks!
PS. I know about package-update-indicator, but I'd like to use plain shell script solution.
You can run apt list --upgradable to get a list of all known available updates.
However, this will not be entirely accurate without updating your package sources first, which requires root permissions (sudo apt update).
apt update manually. systemctl status apt-daily.timer to check that the timer is active, and systemctl status apt-daily.service to see the logs of the last run. When running apt update as user, the following problems appear:
E: Could not open lock file /var/lib/apt/lists/lock - open (13: Permission denied) E: Unable to lock directory /var/lib/apt/lists/ W: Problem unlinking the file /var/cache/apt/pkgcache.bin - RemoveCaches (13: Permission denied) W: Problem unlinking the file /var/cache/apt/srcpkgcache.bin - RemoveCaches (13: Permission denied)
Thus one needs a local version of the lists and the cache - by standard both with read access available, yet no writing allowed. With apt-config dump one will see a list of available options and how to modify them. The relevant ones are these:
Dir::State "var/lib/apt"; Dir::State::lists "lists/"; Dir::Cache "var/cache/apt"; Dir::Cache::archives "archives/"; Dir::Cache::srcpkgcache "srcpkgcache.bin"; mkdir /home/user/apt_local cp -r /var/lib/apt/list /home/user/apt_local/lists cp -r /var/cache/apt /home/user/apt_local/cache apt with modified directoriesapt update -o DIR::State::lists=/home/user/apt_local/lists -o DIR::Cache=/home/user/apt_local/cache apt list --upgradable -o DIR::State::lists=/home/user/apt_local/lists -o DIR::Cache=/home/user/apt_local/cache Of course that easily means a local copy of some 200 MB, and one would have to always make a copy of the latest state to get proper answers.
apt package (see its apt-daily.timer and apt-daily.service).