Backing up your package list WAS screen resolution problems with Hardy Herron

[Owen Townend]

2008/9/28 Derek Broughton <news at pointerstop.ca>:
> Owen Townend wrote:
>
>> 2008/9/28 Derek Broughton <news at pointerstop.ca>:
>>> Owen Townend wrote:
>>>
>>>> Further to that... try something as simple as this to duplicate or
>>>> backup your current set of apps:
>>>> dpkg --get-selections > installed_apps.txt
>>>> dpkg --set-selections < installed_apps.txt
>>>
>>> Well, actually, no.  That's a truly ugly way to install software, and I
>>> heartily recommend NOBODY follow that advice.  You'll never get rid of
>>> all the cruft in future (every single package on the system is now marked
>>> as "manually installed" and will not be removed if nothing needs it in
>>> future).
>>
>> yeah, it was only an example of the possibilities with a single
>> overarching package manager...
>> I agree that NOBODY should actually use that particular method and it
>> was not intended as advice, only as a possibility.
>>
>> Something more like this would probably be closer to useable:
>> $ aptitude search '!(!~i|~M)' -F %p > ${aptlist}
>> (Search for the inverse of anything not installed or installed
>> automatically)
>>
>> What other ways do people use for this type of task?
>
> In fact, that's pretty much exactly what I do - except that I went
> through 'tr' and 'cut' to parse out just the package name.  Doh! Thanks for
> that.
>
> otoh, my search string is simpler: '~i !~M' - installed and Not manual

Great, it's now even less complex.
$ aptitude search '~i!~M' -F '%p' > ${aptlist}
I'm sure I got the inverse syntax expression from an earlier post
around here but googling for '!(!~i|~M)' is no easy thing.

cheers,
Owen.

P.S.
The ~M matches _automatically_ installed packages.