grep -Po '\w+\.\w+$' | sort | uniq -c | sort -rhk1 Bit sloppy because it doesn't pick up the domain names with dashes. But my point was that if you want to bla

grep -Po '\w+\.\w+$' | sort | uniq -c | sort -rhk1 Bit sloppy because it doesn't pick up the domain names with dashes. But my point was that if you want to blacklist *.facebook.com you shouldn't try to enumerate every single variant of it, that's not durable.