Why does "Purge" not remove everything related to an app?

Question

Possible Duplicate:
How can you completely remove a package?

I have learnt that using purge command rather than remove is considered better because purge removes all files related to an app including the config files etc.

Now this has happened before too but as now I dont remember those examples I state my latest encounter-

The Problem-

even after purging,some files remain!

Latest encounter-

cuttlefish( the app from the showdown)

I purged cuttlefish as it was nor working properly whatsoever and then restarted Ubuntu(although that is not necessary) and then re installed it to already find some trigers I had made in the app before deleting it already present! which meant some file(config or something) was not cleared out !

Now i tracked down 2 files in a folder(.cuttlefish) under home and found some files related to plugins and a reflexes.db file(which seems to be the one responsible to contain the triggers i got back on re instal)

I deleted them mannually and did the re install.Though m still facing other problems with the app,Why dint the purge command remove these files?

Thankyou!

Solution 1

The package management never touches any files in a user's home folder so the files there will stay even if you purge a package.

Solution 2

As far I know purge removes a package and it's system wide configuration.

Purging a package wont remove user configurations because what ever created in user directory belongs to user and they are not related to system.

Comments

[Nirmik]

@EliahKagan....okay this link is usefull but then what to do to avoid this "old configuration being used" problem? and basically why was not a new configuration file or here to be specific reflexes.db file created? why was the old one used?

[Eliah Kagan]

To prevent the old, user-specific configuration from being used, delete or rename the old configuration folder (or file, if it's just a single file and not a folder full of files). As for why the old files are not automatically removed or why a new profile is not automatically created after the package is reinstalled, I'm not sure how to answer that, because I'm not sure why you think that should happen. In many package reinstallation situations (where, for example, the package was reinstalled to debug problems not related to user-specific configuration), that would be very bad.

[Nirmik]

Then why is it allowed to the applications to keep their basic files in the home folder? and now that they are,how to tackle with this problem of the configuration or settings being remembered?

[Eliah Kagan]

@Nirmik Durable user-specific files are stored in the home folder. They can't be stored elsewhere, because you don't generally have the ability to create files elsewhere (except when running a program as root).

[Christopher B. Adkins]

Unfortunately you have to remove those files manually. The package management doesn't do this because it didn't create those files (they are created by the programs) and it doesn't know whether they are still in use, for example by a version of the program you have installed without the package manager or because your are using a shared home in a network or multi boot environment.