LED Backpack with raspberry pi 3

ledbackpack.sh

#!/bin/bash
[ -t 0 ] && hash tput 2>/dev/null && COLOR_SHELL=true || COLOR_SHELL=false
function clr_gr()   { [ "$COLOR_SHELL" = true ] && echo "$(tput setaf 0)$(tput setab 2)"; }
function clr_bl()   { [ "$COLOR_SHELL" = true ] && echo "$(tput setaf 7)$(tput setab 4)"; }
function clr_rd()   { [ "$COLOR_SHELL" = true ] && echo "$(tput setaf 7)$(tput setab 1)"; }
function clr_or()   { [ "$COLOR_SHELL" = true ] && echo "$(tput setaf 0)$(tput setab 3)"; }
function clr_ma()   { [ "$COLOR_SHELL" = true ] && echo "$(tput setaf 7)$(tput setab 5)"; }
function endcolor() { [ "$COLOR_SHELL" = true ] && echo "$(tput sgr 0)" || echo "$@"; }

function echo_gr()  { [ "$COLOR_SHELL" = true ] && echo "$(clr_gr) $@ $(endcolor)" || echo "$@"; }
function echo_bl()  { [ "$COLOR_SHELL" = true ] && echo "$(clr_bl) $@ $(endcolor)" || echo "$@"; }
function echo_rd()  { [ "$COLOR_SHELL" = true ] && echo "$(clr_rd) $@ $(endcolor)" || echo "$@"; }
function echo_or()  { [ "$COLOR_SHELL" = true ] && echo "$(clr_or) $@ $(endcolor)" || echo "$@"; }
function echo_ma()  { [ "$COLOR_SHELL" = true ] && echo "$(clr_ma) $@ $(endcolor)" || echo "$@"; }

GIFSDIR="/home/pi/gifs";
RPIProj="/home/pi/rpi-rgb-led-matrix";
TEXTUTIL="$RPIProj/examples-api-use/text-example";
PLAYUTIL="$RPIProj/utils/video-viewer";
sizepartition="200k";

if [[ "$1" == "run" ]]; then
  if [[ $EUID -ne 0 ]]; then
    echo "$0 needs to be run as root!";
    exit 1;
  fi

  function msg() { echo "${@}"; screen -S text -p0 -X stuff "${@}^M"; }

  function statusmsg() {
    if ! screen -ls | grep -q "text"; then
      screen -dmS text $TEXTUTIL --led-rows=32 --led-chain=4 -b 10 -L -f "$RPIProj/fonts/tom-thumb.bdf" -C 255,10,10
      sleep 0.1;
    fi
    msg "LED Backpack";
    msg "  by Tim O'Brien";
    msg "  ";
    msg " $(ls $GIFSDIR | wc -l) gifs loaded";
    msg "  "; msg "  ";
    msg " $(iwgetid | awk '{ print $2; }')";
    msg " $(hostname -I | awk '{print $1}')";
  }

  statusmsg;
  sleep 2;
  msg "^D" # send EOF, closes service

  while true; do
    cd "$GIFSDIR";
    declare -a biggifs smallgifs shuffled;
    while IFS= read -d $'\0' -r file ; do biggifs+=("$file");   done < <(find . -size +${sizepartition} -print0 | shuf)
    while IFS= read -d $'\0' -r file ; do smallgifs+=("$file"); done < <(find . -size -${sizepartition} -print0 | shuf)
    inbetween="$(( ${#smallgifs[@]} / ${#biggifs[@]} ))";
    echo "big: ${#biggifs[@]}, small: ${#smallgifs[@]}, inbetween $inbetween";

    for f in "${biggifs[@]}"; do
      for i in $(seq 1 $inbetween); do
        echo -n "${smallgifs[0]} ";
        shuffled+=("${smallgifs[0]}");
        smallgifs=("${smallgifs[@]:1}");
      done
      echo -n "$(clr_gr)${f}$(endcolor) "
      shuffled+=("${f}");
    done
    for f in "${smallgifs[@]}"; do echo -n "${f} "; shuffled+=("${f}"); done #and all leftovers
    echo_bl "done adding ${#shuffled[@]} files";
    echo_bl "done";

    $PLAYUTIL --led-rows=32 --led-chain=4 -L --led-brightness=50 -r4 "${shuffled[@]}" || exit;
    statusmsg;
    sleep 2;
    msg "^D" # send EOF, closes service
  done

else
  if { screen -ls; sudo screen -ls; } | grep -q "runled|text"; then
    echo "runled screen already running!"
    exit 1;
  fi
  if [[ $EUID -ne 0 ]]; then
    echo "starting screen as sudo";
    sudo screen -dmS runled sudo "$0" run
  else
    screen -dmS runled sudo "$0" run
  fi
fi