all the cool kids are doing it

The ‘diff’ shell command is useful for comparing text files, but also great for comparing shell outputs with this method:

diff <(ls -alh /or/something) <(ls -alh /or/whatever)

Add any favorite flags and go to town.

diff -y --suppress-common-lines <(ls -alh /or/something) <(ls -alh /or/whatever)

(Note: this may not work for all substitutions.)