apt-get --simulate dist-upgrade: What is the meaning of "Inst" and "Conf"?

Question

If I run the command apt-get --simulate dist-upgrade, the output contains a list where each line is prefixed with Inst or Conf, i.e.

[truncated...]
Inst ubuntu-artwork [1:14.04+16.04.20160621-0ubuntu1] (1:14.04+16.04.20160804-0ubuntu1 Ubuntu:16.04/xenial-updates [all])
Inst xdiagnose [3.8.4] (3.8.4.1 Ubuntu:16.04/xenial-updates [all])
Inst xserver-xorg-video-intel [2:2.99.917+git20160325-1ubuntu1] (2:2.99.917+git20160325-1ubuntu1.1 Ubuntu:16.04/xenial-updates [amd64])
Inst p11-kit [0.23.2-3] (0.23.2-5~ubuntu16.04.1 Ubuntu:16.04/xenial-updates [amd64])
Conf libaccountsservice0 (0.6.40-2ubuntu11.2 Ubuntu:16.04/xenial-updates [amd64])
Conf accountsservice (0.6.40-2ubuntu11.2 Ubuntu:16.04/xenial-updates [amd64])
Conf language-selector-common (0.165.4 Ubuntu:16.04/xenial-updates [all])
[truncated...]

from man apt-get

   Simulated runs print out a series of lines, each representing a
   dpkg operation: configure (Conf), remove (Remv) or unpack (Inst).
   Square brackets indicate broken packages, and empty square brackets
   indicate breaks that are of no consequence (rare).

Does Conf mean if apt-get dist-upgrade was run, the packages marked with Conf would only have their configuration scripts run, i.e. the same as dpkg-reconfigure? The man pages description of Inst says "unpack", this suggests to me, the package will be downloaded an unzipped, but that doesn't seem to make much sense.

What is the meaning of "Inst" and "Conf"?

Answer 1

You need to look at the man page for dpkg for the "represented dpkg operations".

Excerpts from man dpkg:

Install

-i, --install package-file...
      Install the package. If --recursive or -R option is specified, package-file must refer to a directory instead.

      Installation consists of the following steps:

      1. Extract the control files of the new package.

      2. If another version of the same package was installed before the new installation, execute prerm script of the old package.

      3. Run preinst script, if provided by the package.

      4. Unpack the new files, and at the same time back up the old files, so that if something goes wrong, they can be restored.

      5. If another version of the same package was installed before the new installation, execute the postrm script of the old package. Note that
         this script is executed after the preinst script of the new package, because new files are written at the same time old files are removed.

      6. Configure the package. See --configure for detailed information about how this is done.

Unpack

--unpack package-file...
       Unpack the package, but don't configure it. If --recursive or -R option is specified, package-file must refer to a directory instead.

Configure

--configure package...|-a|--pending
       Configure a package which has been unpacked but not yet configured.  If -a or --pending is given instead of package, all unpacked but uncon‐
       figured packages are configured.

       To reconfigure a package which has already been configured, try the dpkg-reconfigure(8) command instead.

       Configuring consists of the following steps:

       1. Unpack the conffiles, and at the same time back up the old conffiles, so that they can be restored if something goes wrong.

       2. Run postinst script, if provided by the package.

Note that Install performs both Unpack and Configure, which is why they are listed separately by apt-get.