[Slackbuilds-users] Slackbuilds: doinst.sh and douninst.sh

[Alessandro Baggi]

Hi Watson,

Il 19/07/24 21:46, B. Watson ha scritto:
> 
> 
> On Fri, 19 Jul 2024, Alessandro Baggi wrote:
> 
>> 3. A clean process during package uninstall that clean created 
>> user/group, start/stop system configuration in rc.local/rc.local_shutdown
> 
> Again I will say it:
> 
> Packages get *removed* when they get upgraded.
> 
> Anything a douninst.sh script does, happens when the package gets
> upgraded. The douninst.sh script doesn't know know whether it's being
> run due to a permanent removal or due to an upgrade.
> 
> Do you really want to delete the postgres user during the upgrade process?
> 
> Normally when you delete a user, you delete the user's files, too 
> (userdel -r).
> 
> If you don't delete the files, upgrades are safe. 

this is a good point but it is not better to instruct slackpkg or 
upgradepkg or whatever to not run douninst.sh when upgrading packages? 
This seems a pkgtool feature lacks.

But in that case,
> if someone really does permanently remove the postgresql package, it's
> not a clean removal: all the data that was in the databases is still
> on the filesystem, taking up space... and no longer owned by any user.

Generally, from my point of view, when a package is deleted the package 
manager should not delete application data and this is a common 
behaviour also in apt and dnf. There is a difference between system 
configuration (replicable), application files and real data (not 
replicable). A clean removal is meant by me like "the application is no 
more present on the system" and should not consider user data but only 
app configuration and binary/libs/etc of the specified application.

Following your "clear all suggestion" and running an upgrade, being the 
package removed and reinstalled, all useful data (reproducible like 
configuration and not reproducile data like db records) will be deleted 
making the new installation broken because user loses all data, so is 
better to instruct pkgtool to assume the right behaviour when upgrading.

Sometimes package manager should be updated with new feature or existent 
features enhancement.