dpkg, APT & Aptitude commands

List all recently installed packages:

$ zcat -f /var/log/dpkg.log* | grep "\ install\ " | sort

Install a package from a lower-priority repository, like the backport repository:
```
$ apt-get -t squeeze-backports install my-package
```

Force reinstallation of a package:

$ apt-get -d --reinstall install my-package
$ dpkg --install --force-confmiss /var/cache/apt/archives/my-package.deb

Clean aptitude local cache:
```
$ apt-get clean
```
Uninstall a package throughly (both program files and configuration):
```
$ apt-get remove --purge my_package
```
Force removal of a package while ignoring all dependencies:
```
$ dpkg --remove --force-depends libsomething
```

Remove orphaned pakages:

$ deborphan | xargs apt-get -y remove --purge

Show the changelog of a package (here, the linux kernel of Ubuntu):
```
$ aptitude changelog linux-generic
```
Which package contain a given file:
```
$ apt-file search file_to_search
```
Get the list of files of a package:
```
$ apt-file list package_name
```
Remove dpkg lock file:
```
$ rm /var/lib/dpkg/lock
```

Hold a package with either dpkg or aptitude:

$ echo "kdenlive hold" | dpkg --set-selections

or:

$ aptitude hold kdenlive

Unhold a package:

$ echo "kdenlive install" | dpkg --set-selections

or:

$ aptitude unhold kdenlive