nc(1) on OpenBSD
The text 1a50827707c4, as OpenBSD 2.2, OpenBSD 2.1 shipped it.
Arbitrary tcp and udp connections and listens. nc [-e command] [-g intermediates] [-G hopcount] [-i interval] [-lnrtuvz] [-o filename] [-p source port] [-s ip address] [-w timeout] [hostname] [port[s...]]
Flags it lists
-
-G -
-e -
-g -
-i -
-l -
-n -
-o -
-p -
-r -
-s -
-t -
-u -
-v -
-w -
-z