<b_jonas> slashlearn euclid//Euclid is a short geeky game in which the goal is to do Euclidean compass and straightedge constructions in as few steps as possible. It runs in the browser, found at "http://www.euclidthegame.com/". It was popular among #esoteric regulars in 2016-07.

line="${1-$(cat $HACKENV/tmp/spline)}"; len="$(awk 'END{print NR}' $HACKENV/tmp/spout)"; echo -n "$line/$len:"; sed -n "${line}{p;q}" $HACKENV/tmp/spout; echo "$((line<len?line+1:1))" > $HACKENV/tmp/spline