lsd bash script, inspired by Aniket-Pradhan/lsd

lsd.sh

#!/usr/bin/env bash
# Copyright © 2019 mpan; <https://mpan.pl/>; CC0 1.0 (THIS FILE!)

declare -ri rows="$(tput lines)"
declare -ri columns="$(tput cols)"

declare -ra codes=(
    "$(tput setab 0) "
    "$(tput setab 1) "
    "$(tput setab 2) "
    "$(tput setab 3) "
    "$(tput setab 4) "
    "$(tput setab 5) "
    "$(tput setab 6) "
    "$(tput setab 7) "
    "$(tput setab 8) "
    "$(tput setab 9) "
    "$(tput setab 10) "
    "$(tput setab 11) "
    "$(tput setab 12) "
    "$(tput setab 13) "
    "$(tput setab 14) "
    "$(tput setab 15) "
)

rowFormat=''
for ((iColumn = 0; iColumn < columns; ++iColumn)); do
    rowFormat+='%s'
done
format=''
for ((iRow = 0; iRow < rows - 1; ++iRow)); do
    format+="$rowFormat"
    format+=$'\n'
done
format+="$rowFormat"
declare -r format

declare -a screen
for ((iRow = 0; iRow < rows; ++iRow)); do
    for ((iColumn = 0; iColumn < columns; ++iColumn)); do
        screen+=("${codes[0]}")
    done
done

while true; do
    tput cup 0,0
    for ((iRow = 0; iRow < rows; ++iRow )); do
        for ((iColumn = 0; iColumn < columns; ++iColumn)); do
            color=$(( RANDOM % "${#codes[@]}" ))
            screen["$((iRow * columns + iColumn))"]="${codes[$color]}"
        done
    done
    printf "$format" "${screen[@]}"
done