Re: Removing Unused Programs

[Florian Kulzer <florian@molphys.leidenuniv.nl>]

On Thu, Feb 08, 2007 at 11:53:37 +0000, Chris Lale wrote:
> Florian Kulzer wrote:

[...]

> >You can tell aptitude to purge unused packages:
> >
> >$ man aptitude 2>/dev/null | grep -A3 purge-unused
> >       --purge-unused
> >          Purge packages that are no longer required by any installed 
> >          package.
> >          This is equivalent to passing "-o Aptitude::Purge-Unused=true" 
> >          as a
> >          command-line argument.
> >  
> 
> Does this command purge packages no longer required by "harvestman", or 
> does it purge all unused packages?
> 
>    # aptitude --purge-unused purge harvestman

This will purge all "auto" packages which are unused (but still
installed) at that moment (and it will purge harvestman, of course). I
just played around with this a bit and it seems to me that the best way
to understand the "--purge-unused" option is to think of it as
transforming all automatic "remove" actions into "purge" actions. This
is independent of the primary command, i.e.

aptitude --purge-unused remove harvestman

will still purge all the installed, unused "auto" packages while it will
leave harvestman's configuration files in place. (Or rather, it would
leave harvestman's config files in place if harvestman had any config
files to begin with. Harvestman is not a good example in this respect.)

This also means that "--purge-unused" will not have any effect if you
have disabled the automatic removal of unused packages in aptitudes
configuration. The description in the manpage does not make this clear
but I just tried it and found that disabling automatic removals
neutralizes the --purge-unused option. (aptitude 0.4.4-1)

> Can you do this without specifying a package?

Yes, you can run "aptitude --purge-unused install" or any other command
which will trigger automatic removal of unused packages.

If you want to purge all packages which were already removed at an
earlier time (be that automatic or manual removal) then you can use

aptitude purge '~c'

This is probably too harsh in most cases, so you might want to run

aptitude search '~c'

instead and decide yourself which packages you want to purge. This works
even better in interactive mode where you can use "~c" (without the
quotation marks) as the display limit criterion and then go over the
list package-by-package; press "_" whenever you want to purge one.

-- 
Regards,
          Florian