[mVChr]

> (and there doesn't seem to be a way to resolve usernames, as `netstat -e` does)

Challenge accepted:

  ss -e | grep uid | gawk 'match($0,/uid:([0-9]+)/,u) {printf "%s user:",$0;system("getent passwd "u[1]" | cut -d: -f1");}'

Not your point, I know, but it was fun.

[wang_li]

You lose three points for using grep and gawk in the same pipeline. :P

[mVChr]

Oops, the grep was just to filter the lines that actually have a uid while I worked on it, it's not needed or desired if you were to actually use this. You can remove that part. :P