<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.

#!/bin/sh
allquotes | if [ "$1" ]; then
    if expr "$1" + 0 >/dev/null 2>&1; then
        sed "$1q;d"
    else
        grep -P -i -- "$1"
    fi
else shuf --random-source=/dev/urandom -n 1; fi