See end-nodes of dependency graphs

Question

I'm using Arch Linux, with its Pacman package manager. I want to keep my system as clean as possible, and that includes not having any unused packages installed. But, because of dependencies, it's not a trivial task to have zero of such, at least with my level of knowledge. Is there any tool available, console or GUI, that will show me all installed packages that nothing depends on?

Answer 1

From the Arch Wiki:

To list all packages no longer required as dependencies (orphans):
$ pacman -Qdt

Or, to recursively remove orphans:

orphans() {
  if [[ ! -n $(pacman -Qdt) ]]; then
    echo "No orphans to remove."
  else
    sudo pacman -Rs $(pacman -Qdtq)
  fi
}

Answer 2

pacman -Qt prints packages whose doesn't need on system (maybe you need it). I hope I didn't misunderstand you.

Answer 3

You usually want to see a list of end-user programs you have installed:

pacman -Qte

where t lists the end nodes of the dependency graph (the packets not required by other installed packets) and e filters out only explicitly installed packages.

If you always forget what these programs are for (like I do), try:

pacman -Qtei | grep -P "Name|Description"

After uninstalling, use

pacman -Rs $(pacman -Qqtd)

To remove all orphan packages

Last idea taken from Pacman Tips.