YJL

Frankly, I am embarrassing myself for posting this piece of Bash. Initially, I wrote a one-liner to fill entire terminal space with checkerboard pattern, then I realized that I could shift a bit, that would look like as seen above, as if walking on checkerboard, hence the following code:

C=(
  $'\e[48;5;16m  \e[48;5;231m  \e[0m'
  $'\e[48;5;231m  \e[48;5;16m  \e[0m'
  $'\e[48;5;16m \e[48;5;231m  \e[48;5;16m \e[0m'
  $'\e[48;5;231m \e[48;5;16m  \e[48;5;231m \e[0m'
)

i = 0
while :; do
  for ((y = 1; y <= LINES; y++)); do
    for ((x = 1; x <= COLUMNS / 4; x++)); do
      echo -n \
        "${C[((i * 2) % 4) + ((y + i / 2) % 2)]}"
    done
    ((y == LINES)) || echo
  done
  sleep 0.25
  ((i = ++i % 4)) && echo
done

I wasn’t feeling to make it compact or clean. Since it’s already been written, I might just post it instead of stuffing it somewhere on disk that I would forget in just a few days.