It is good to know how to tell to which package the specified file belongs to as this knowledge could be very useful during system upgrade or unexpected system failure.
Identify specified file
Use the full path to check specified file.
$ dpkg-query -S /usr/sbin/apt-cacher-ng apt-cacher-ng: /usr/sbin/apt-cacher-ng
The following message identify file that does not belong to any installed package.
$ dpkg -S $(which youtube-dl) dpkg-query: no path found matching pattern /usr/local/bin/youtube-dl
Search for pattern
You can also search using just part of the filename.
$ dpkg-query -S awstats.conf awstats: /etc/awstats/awstats.conf.local awstats: /etc/awstats/awstats.conf
Notice that matching pattern used in the above example will be expanded to the
*awstats.conf* (see notes for clues).$ dpkg-query -S *awstats*[pn][lf] awstats: /usr/share/doc/awstats/examples/maillogconvert.pl awstats: /usr/share/doc/awstats/examples/awstats_updateall.pl awstats: /usr/share/doc/awstats/examples/urlaliasbuilder.pl awstats: /usr/share/doc/awstats/examples/geoip_generator.pl awstats: /usr/share/awstats/tools/logresolvemerge.pl awstats: /usr/share/doc/awstats/examples/awstats_configure.pl awstats: /usr/share/doc/awstats/examples/apache.conf awstats: /usr/lib/cgi-bin/awstats.pl awstats: /usr/share/doc/awstats/examples/awstats_exportlib.pl awstats: /etc/awstats/awstats.conf awstats: /usr/share/awstats/tools/awstats_buildstaticpages.pl
Take a look inside specified directory
You can easily check whole directory instead of the files directly.
$ dpkg-query -S /usr/src linux-kbuild-3.2, base-files, linux-headers-3.2.0-4-amd64, linux-headers-3.2.0-4-common, virtualbox-dkms: /usr/src
$ dpkg-query -S /usr/src/* linux-headers-3.2.0-4-amd64: /usr/src/linux-headers-3.2.0-4-amd64 linux-headers-3.2.0-4-common: /usr/src/linux-headers-3.2.0-4-common linux-kbuild-3.2: /usr/src/linux-kbuild-3.2 virtualbox-dkms: /usr/src/virtualbox-4.1.18
Notes
To understand when and how matching pattern is expanded look at the searchfiles function defined inside src/querycmd.c file in dpkg source code.
dpkg-query can be used only to query the dpkg database, although you can use full fledged dpkg command.
$ dpkg -S /usr/sbin/apt-cacher-ng apt-cacher-ng: /usr/sbin/apt-cacher-ng