On Thursday 04 January 2007 12:31, Uwe Thiem <uwix@iway.na> wrote 
about 'Re: [gentoo-user] pruning distfiles':
> On 04 January 2007 20:18, Stuart Howard wrote:
> > On 04/01/07, Uwe Thiem <uwix@iway.na> wrote:
> > > Hi folks,
> > >
> > > just went through /usr/portage/distfiles and deleted what I though
> > > was outdated - a major PITA. There must be a better way!
> > >
> > > Slight complication: My portage tree is used by different boxes with
> > > different world files.

My roommate and I also have a shared distfiles.  We clean daily by placing 
the following script in /etc/cron.daily:
#!/bin/sh

if [ -x /usr/bin/eclean ]; then
        # If you want you can also add a grace period,
        # so files downloaded within
        # the last week (e.g.) will not be deleted.
        /usr/bin/eclean -q distfiles
else
        echo 'eclean not found in expected location; not cleaning 
distfiles.' >2
        exit 1
fi

> > I use this as a cron
> > 00 6 11 * * /usr/bin/eclean-dist -fd
> eclean-dist was the one I couldn't remember.
>
> Having had a brief look at eclean-dist, I don't think it uses the world
> file but the database of installed packages.

Non-destructive mode uses the portage tree (that is, if any existent ebuild 
could use the file, it stays).  IIRC, this includes overlays, but may not 
include installed packages no longer in the tree.

Destructive mode does use the database of installed packages, so it won't 
remove anything needed by the ebuild(s) you currently have installed.

-- 
"If there's one thing we've established over the years,
it's that the vast majority of our users don't have the slightest
clue what's best for them in terms of package stability."
-- Gentoo Developer Ciaran McCreesh