Editing Debian package management (section)

== dpkg, dpkg-query, dpkg-deb ==

=== dpkg ===

* https://manpages.debian.org/unstable/dpkg/dpkg.1.en.html

==== installing a Debian package ====
<pre>$ sudo dpkg --install PACKAGE.deb</pre>

==== removing a Debian package ====
<pre>$ sudo dpkg --remove PACKAGE</pre>

==== verifying a Debian package ====
<pre>$ sudo dpkg --verify PACKAGE</pre>

=== dpkg-deb -- Debian package archive (.deb) manipulation tool ===

* https://manpages.debian.org/unstable/dpkg/dpkg-deb.1.en.html

'''dpkg-deb''' packs, unpacks and provides information about Debian archives.

Use '''dpkg''' to install and remove packages from your system.

==== which files are included? will be created from this package file? ====
<pre>$ dpkg-deb --contents PACKAGE.deb</pre>

==== what's the official package name? ====
<pre>$ dpkg-deb --info PACKAGE.deb</pre>

==== what is the content of the ctrl-tarfile you can extract from PACKAGE.deb? ====
<pre>$ dpkg-deb --ctrl-tarfile PACKAGE.deb | tar tvf  -
drwxr-xr-x root/root         0 2018-08-27 17:39 ./
-rw-r--r-- root/root     21773 2018-08-27 17:39 ./md5sums
-rw-r--r-- root/root       229 2018-08-27 17:39 ./control
-rw-r--r-- root/root      1071 2018-08-27 17:36 ./conffiles
-rwxr-xr-x root/root      1228 2018-08-27 17:39 ./postinst</pre>

* PACKAGE.deb contains a tarball (ctrl-tarfile).
* the tarball contains ... .

==== what conffiles does PACKAGE.deb contain? ====
<pre>$ dpkg-deb --ctrl-tarfile PACKAGE.deb | tar xf  - --to-stdout ./conffiles</pre>

* PACKAGE.deb contains a tarball (ctrl-tarfile), 
* the tarball contains ./conffiles,
* ./conffiles is only a list of what is to be treated as conffiles, it does not contain the conffiles themselves, they are an ordinary part of PACKAGE.deb

=== dpkg-query ===

* https://manpages.debian.org/unstable/dpkg/dpkg-query.1.en.html

==== which packages are installed (together with a '''couple''' of details)? ====
<pre>$ dpkg-query --list</pre>

==== is there an installed package, that sounds like XYZ? ====
<pre>$ dpkg-query --list | fgrep XYZ</pre>

==== details of an installed package (that you know the name of, e.g. PACKAGE) ====
<pre>$ dpkg-query --list PACKAGE</pre>

==== all details of specified package ====
<pre>$ dpkg-query --status PACKAGE</pre>

==== what's the content of an installed package (e.g. PACKAGE) ====
<pre>$ dpkg-query --listfiles PACKAGE</pre>

==== what conffiles does an installed package (e.g. PACKAGE) include ====
<pre>$ dpkg-query --showformat='${Conffiles}\n' --show PACKAGE
$ dpkg-query --showformat='${Conffiles}\n' --show PACKAGE | perl -pe 's/^ \s* (.*?) \s* \w+ $/$1/x'</pre>

===== backup all the conffiles of an installed package (e.g. PACKAGE), each one for itself =====
<pre>$ sudo ~jochen.hayek/bin/create_snapshot.sh $( dpkg-query --showformat='${Conffiles}\n' --show PACKAGE | perl -pe 's/^ \s* (.*?) \s* \w+ $/$1/x' )</pre>

===== backup all the conffiles of an installed package (e.g. PACKAGE) to a single tarball =====
<pre>$ sudo tar cvf ~/tmp/PACKAGE.conffiles-$(date '+%Y%m%d%H%M%S').tar --directory / $( dpkg-query --showformat='${Conffiles}\n' --show PACKAGE | perl -pe 's/^ \s* (.*?) \s* \w+ $/$1/x' )</pre>

==== which installed package includes a certain FILE (utility, ...)? ====
<pre>$ dpkg-query --search FILE</pre>