Every once in a while, I make a vain attempt to clean up packages. Lately, I've been upping my game in searching for packages I don't use anymore or don't have any recollection I even installed. In this article, I'll run through one full cleanup cycle using pacman to declutter my Arch Linux machine.

Removing installed packages

There are two kinds of packages to look at:

• Native - packages that appear in the sync database(s)
  • You installed these with pacman -S¹
• Foreign - packages you've installed from other sources
  • For example, you downloaded a PKGBUILD from the AUR and installed it with makepkg

I usually deal with these one at a time.

Pruning foreign packages

I typically start with foreign packages. I prune these aggressively as foreign packages have no particular security standard - it'll vary by where you got the package from.

You can list foreign packages like so:

$ pacman -Qqme
autojump
kanata-bin
wdisplays
[...]

The options are as follows:

• Q - query, we're querying the local database
• q - quiet, show less output
• m - foreign, as described above
• e - explicitly installed, as opposed to having been installed as a dependency of something else

Let's say I want to uninstall wdisplays. I'd do that like so:

$ sudo pacman -Rsn wdisplays
checking dependencies...

Packages (2) wayland-protocols-1.45-1  wdisplays-1.1.3-1

Total Removed Size:  1.02 MiB

:: Do you want to remove these packages? [Y/n]

Note that the we're prompted to approve the removal², and also that prompt lists two packages for removal: wdisplays and wayland-protocols. The latter is a dependency of wdisplays, which shows up due to the use of the s option, as specified below:

• R - remove, we're removing a local package
• s - recursive, remove all dependencies of the package provided that they have no other dependents and were not explicitly installed by the user
• n - nosave, prevents Pacman from backing up removed files (I really want them gone)

Aside: Another useful option -c|--cascade. By specifying this, you will remove not only the target package, but any package that depends on it, recursively. I rarely use this myself, but it can be very convenient if there's a "middle of the dependency chain" package that you for one reason or another really need to remove.

Pruning native packages

Now, we follow precisely the same procedure for native packages. To list native packages, we simply substitute the m option with the n argument.

$ pacman -Qqne
[... very long list ...]

This list is going to be way larger than your list of foreign packages, so you might want to pipe the result to less and have a little look through it. Generally, I do not prune this as aggressively as I prune my foreign packages as the security standards in the official Arch repositories are adequate for my needs. That being said, it's still worth a little look every now and then, as every installed package makes system updates slower.

When you find something to uninstall, you use precisely the same command as for a foreign package above.

Pruning orphaned packages

As a final step, I prune orphaned packages. These are packages that were installed as dependencies at one point, but no longer have any dependents. I typically accrue quite a few of these by forgetting the s option when removing packages, but they can also come about from e.g. a system update (pacman -Syu) where some updated package(s) no longer require prior dependencies. A system update does not remove orphans, meaning that you'll accumulate orphans in the system through normal usage.

You can list orphaned packages like so:

$ pacman -Qqdt
[...]

The new arguments are as follows:

• d - dependencies, only shows packages that were not explicitly installed
• t - unrequired, lists packages that have no dependents

This will often be quite a large list, typically with dozens or hundreds of entries depending on how often you clean up your system, so it's typically necessary to pipe it to the removal command.

$ pacman -Qqdt | sudo pacman -Rsn -
[...]

:: Do you want to remove these packages? [Y/n]

As usual, you need to confirm your action via the prompt, and the presence of the s option will likely cause the prompt to show more packages than the list you piped into it.

Important: The q option is actually important in the above command chain, as the extra information that's printed if you don't specify it causes pacman -R to error out.

Tip: You can trim the list a bit by adding the t option to exclude packages that are dependencies of other packages. Most often, I find that these packages are indeed packages that I want to keep, and I only explicitly installed them to resolve some issue with an update.

Further reading

If you want to learn more about how to maintain your system, here are a few additional resources to have a look at.

• The System maintenance page in the Arch Linux Wiki is a must-read for maintaining your system properly
• The pacman/Tips and tricks page in the Arch Linux Wiki is a great place to get ideas for what you can do with pacman. It's essentially a much more comprehensive version of this very article.
• The manual page (man pacman) is very useful once you already know roughly what you want to do

And that's it!

With that, you've learned how to prune packages on your system! It's not difficult to do, you just need a little bit of discipline to do it regularly. Pruning packages may seem unnecessary, but it has several benefits, not least of which is a smaller attack surface, less wasted disk space and faster system updates.

1. Or if you're a good citizen, you installed them with pacman -Syu to ensure you're all up to date ↩
2. For scripts, you can bypass the need for a prompt with --noconfirm. I tend to not script my system maintenance, however, as I like to be hands on when it comes to what's installed on my system. ↩