How to make `du` only include regular files in its output?

Question

I want to list all files in descending order based on disk usage, and have obtained the following commands from this:

To list the top 10 largest files from the current directory: du . | sort -nr | head -n10

To list the largest directories from the current directory: du -s * | sort -nr | head -n10

However, they both list only directories.

How can I make du only include regular files in its output?

Bonus:

What is the following du option used for (it seems to have no effect)?:

 -a, --all             write counts for all files, not just directories 

Answer 1

IF you have GNU du, then send it a list of regular files (or directories, or whatever you want to filter on) using find (or as arguments using shell globs in zsh):

find . -type f -print0 | du --files0-from=-
du *(.)  # zsh, regular non-hidden files in the current directory

du by default prints only the sum of the file sizes inside a directory for that directory, but you can have it print those individual file sizes too, which is what -a does:

% du /usr/bin
68  /usr/bin/lou_maketable.d
100 /usr/bin/vendor_perl
464 /usr/bin/core_perl
4   /usr/bin/site_perl
1104024 /usr/bin
% du /usr/bin -a | head
4   /usr/bin/preparetips5
36  /usr/bin/autoupdate
4   /usr/bin/python3.9-config
0   /usr/bin/mkoctfile
60  /usr/bin/zdump
16  /usr/bin/fstopgm
4   /usr/bin/brltty-setcaps
40  /usr/bin/sleep
8   /usr/bin/pnmquantall
20  /usr/bin/extract_mpeg2