First, an introduction. I just found a development server with all kinds of GUI packages installed. I'd like to know why. Therefore, I'd like to know which software has been installed that requires X.

I can answer this by answering two closely related questions:

  • How can I list all installed packages that no other package depends on?
  • How can I list all installed packages that no other package depends on, and that, directly or indirectly, depend on a given package? (E.g., x11-common.)

For the first question, apt-mark showmanual is a useful approximation, but it may not be exactly right.

For the second question, what I'm using now postprocesses the apt-rdepends output to list only results for which no dependencies are listed that are listed as results.

Is this correct? Is there an easier way? I notice the result contains quite a few packages that aren't marked as manually installed.

I need this on Ubuntu 14.04, 16.04, and 18.04.

  • Why not look at /var/log/apt? You should be able to see the install history there.
    – waltinator
    Feb 1, 2019 at 14:13
  • I don't want to pick logfiles apart by hand, I want those packages listed. Besides, by default, those logs don't last forever. Feb 1, 2019 at 14:15
  • I'm not sure that "all installed packages that no other package depends on" is going to be a very useful list (it's going to include essential "top level" packages such as login for example) but I guess you could parse the output of aptitude why e.g. dpkg --get-selections | while read pkg status; do [[ "$status" == "install" ]] && { aptitude why "$pkg" | grep '^Unable to find a reason'; }; done . It will be painfully slow (but you might not care, for a one-off). Feb 1, 2019 at 16:26
  • Just an idea: Automatically installed packages that no other packages depends on, are removed as unused packages by aptitude, provided the options APT::Install-Recommends and APT::AutoRemove::RecommendsImportant are set to false. Or do you also want the manually installed packages that are not depended upon by any other package? Feb 1, 2019 at 16:50
  • Basically, I want all software that was explicitly installed, rather than as a dependency of something else, even if that something else was installed later. I'm not sure just taking all packages resulting from apt-mark showmanual gives me that. Apr 11, 2019 at 13:35

1 Answer 1


You can for example list all installed packages with dpkg-query and then pipe the package names to apt-cache to see whether they have any reverse depedencies. Here's a one way to do it:


dpkg-query --show --showformat='${Package}\t${Status}\n' | sed --quiet '
        s/^/apt-cache rdepends --installed /
        s/\n/ /g                                                        

if you want to do the reverse and list packages with at least one reverse dependency, just change /:$/ to /:$/!

  • 2
    Very nice. The repeated calls to apt-cache make it slow though - I've amended it to dpkg-query --show --showformat='${Package}\t${Status}\n' | tac | awk '/installed$/ {print $1}' | xargs apt-cache rdepends --installed | tac | awk '{ if (/^ /) ++deps; else if (!/:$/) { if (!deps) print; deps = 0 } }' Mar 12, 2021 at 20:12
  • 1
    Great job, that's way faster than the version in my answer; I forgot that apt-cache can accept multiple arguments. Mar 12, 2021 at 20:33
  • I learnt some sed along the way - I never knew it has an e command ... Mar 12, 2021 at 20:44
  • 1
    As far as I know only the GNU version supports it. Mar 12, 2021 at 21:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.