where is the list of installed packages kept?

[Derek Broughton]

stan wrote:

> On Fri, Jan 19, 2007 at 03:05:05PM -0800, Mitch Contla wrote:
>> stan said the following on 01/19/2007 12:24 PM:
>> > I'm rebuilding a machine, and I forget to get a list of the installed
>> > packages on the original one. I do howeverr have a tarball of the whole
>> > root filesystem on that machine.
>> >
>> > Where in that can I look for the list of installed .debs?
>> >
>> >   
>> A quick look at some Debian docs, and a poke around my system looks like
>> package information is contained in /var/lib/dpkg/status. Once you
>> un-tar the file, you could try something like:
>> 
>> $ cat /var/lib/dpkg/status | grep -B1 'ok installed' > selections
>> 
>> >From there you could use sed an create something that could be recovered
>> using:
>> 
>> $ sudo dpkg --set-selections < myselections
>> $ sudo apt-get -u dselect-upgrade
>> 
>> See the Debian Reference; specifically: 6.3.4 Recover package selection
>> data and 6.4.9 Record/copy system configuration.
>> 
>> Of course, others may know an easier way. Good Luck.

That's best (or Peter's method) if you don't already have a list. 
Unfortunately everything is marked as manually installed.

I run this in cron.weekly:
 aptitude search '~i !~M' | tr -s ' ' | cut -f 2 -d ' '  \
  >/etc/apt/installed.txt

That creates a list of all the packages that have not been automatically
installed as dependencies.  When I built a new machine, I used:

 $ sudo dpkg --set-selections < /etc/apt/installed.txt
 $ sudo aptitude install

Now, if I remove any of these packages, their dependencies will be removed
automatically if not needed.
-- 
derek