On Sun, 23 Aug 2009, Robert P. J. Day wrote:
> On Sun, 23 Aug 2009, Jörg-Volker Peetz wrote:
>
> > Robert P. J. Day wrote:
> > > this should be an easy one: on my current (etch) system, there are
> > > a number of packages that have more than one version installed. for
> > > example (and from memory), there are at least three versions of gcc
> > > installed. am i safe to remove/purge the older ones?
> > >
> > > perhaps a better question is, what is the command to list the
> > > packages that depend on a certain package? in fedora, i'm used to
> > > running:
> > >
> > > $ rpm -q --whatrequires <package>
> > >
> >
> > aptitude comes in handy here:
> >
> > aptitude search '~i~D^<package>$'
> >
> > Since aptitude uses regular expressions search <package> is enclosed
> > by ^ and $ to distinguish, e.g., between gcc-4.3 and gcc-4.3-doc.
>
> i'm not sure what that's supposed to show me. let me give you an
> example from my running lenny system. if i run:
>
> $ apt-cache rdepends acpid
>
> i get a list that includes, among other things, two installed
> packages -- acpi-support and acpi-support-base -- and a bunch of other
> packages that *aren't* installed.
>
> what i want now is a way to list only the *installed* reverse deps
> of acpid. if i run (as you suggest):
>
> $ aptitude search '~i~D^acpid$'
>
> i get null output. what do you *think* i should see?
never mind, i just found the "apt-rdepends" package, with cool
options like "--state-show=installed". someone might have mentioned
that package earlier. :-)
rday
--
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Robert P. J. Day Waterloo, Ontario, CANADA
Linux Consulting, Training and Annoying Kernel Pedantry.
Web page: http://crashcourse.ca
Twitter: http://twitter.com/rpjday
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