carpet.sh

#!/bin/sh

set -o errexit
set -o nounset

tile() {
  printf "%s\033[1B\033[3D%s\033[1B\033[3D%s\033[2A" '╲┴╱' '┤╳├' '╱┬╲'
}

printf "\033[2J\033[H"

i=0
i_end=$(($(tput lines) / 3 - 1))
while [ "$i" -le "$i_end" ]; do
  j=0
  j_end=$(($(tput cols) / 3 - 1))
  while [ "$j" -le "$j_end" ]; do
    tile
    j=$((j+1))
  done
  printf "\n\n\n"
  i=$((i+1))
done