mjhjmtu

I'm using arch linux.

Is there a way to list optional dependencies of all installed packages? And if yes, can I filter this list to see only the missing (not installed) packages?

There is a nice utility in the AUR-Repository (aur/pacdep).

pacdep has a lot of options - just one example - find out optional packages for "thunar-archive-plugin":

> pacdep -oppp thunar-archive-plugin
[...]
Optional dependencies: 6.16 MiB
 extra/file-roller 3.89 MiB
 extra/kdeutils-ark 1.12 MiB
 community/xarchiver 1.16 MiB
[...]

The output above means that none of the optional packages are installed.
After installing "xarchiver" the output looks like

[...]
Optional dependencies: 6.16 MiB
 local: 1.16 MiB
 xarchiver 1.16 MiB
 sync: 5.01 MiB
 extra/file-roller 3.89 MiB
 extra/kdeutils-ark 1.12 MiB
[...]

I found (the first part of) this answer on
http://mywaytoarch.tumblr.com/post/34979742718/easily-list-package-dependencies

You can use expac to query the pacmandatabase.

Something like:

awk 'NF>=2' <(expac "%n %O") > optdeps

will print a list of all the installed packages on your machine and the optdepends for each one (%O)¹ to a file called optdeps. You could then sort this against a list of installed optdepends packages.

See man expac for the complete list of options.

^{1. That is an upper case O, not a zero. Because we can't have a font that distinguished between the two...}

Though I've had to notice that @DarkHeart's solution doesn't really work, it inspired me to make a working one. (no colours, though)

I'm using package-query, a similar tool instead of expac which was suggested by @jasonwryan, because I've had it already installed (it's a dependency of yaourt). It should be trivial to change this to use expac instead.

The listing of all optional dependencies is mostly done by the call to package-query. The first for-loop removes the explanations, so just the package names for the optional dependencies remain; the second for-loop removes the already installed dependencies in its first line before printing the results in the second one.

#!/usr/bin/perl
use strict;
use warnings;

my %deps;
for (`package-query -Q -f'%n %O'`) 
 $deps (/^(S+)/)[0] = [/(S+):/g];

my @pkgs = keys %deps;
for my $pkg (@pkgs) 
 my @missing_deps = grep !($_ ~~ @pkgs) @ $deps$pkg ;
 print "$pkg => @missing_depsn" if @missing_deps;

This is not exactly efficient, but will find what you want (in COLOR!):

pacman -Q > /tmp/paccache
for pkg in $(awk 'print $1' /tmp/paccache) ; do 
 echo -n "$pkg => "; 
 for dep in $(pacman -Qi $pkg | awk -F: '/Optional Deps/gsub(/[<>=].*/,"");print $NF;' ) ; do 
 grep -q "$dep" /tmp/paccache && COLOR=32 ; echo -en "e[1;$COLOR:-31m$depe[0;m " ; unset COLOR ; 
 done 
 echo
done 

This should do the trick:

comm -23 <(expac -l"n" "%o" | sort -u) <(expac -l"n" "%nn%S" | sort -u)

First input to comm lists all optional dependencies, second input all installed packages and their 'provide' attributes. Both lists are sorted and contain each element only once due to sort -u. Then only lines are shown that are contained in the first but not in the second list.

(edited to incorporate @Archemar's suggestion)

Sometimes you have to work backwards... first find all non-optional depends, then cross-reference with full list, then use uniq.

Find all installed

pacman -Q

Find all non-optional:

pacman -Qent

Unique entries must therefore be optional:

(pacman -Q; pacman -Qent) | sort | uniq -u