function you can place in your scripts and call on any command where you want progress animations. replaced the earlier snippet that was less plug and play. the characters in $loop can be replaced with other characters - printf prints 3 individual random characters from the string stored in $loop

progress-bar-function.sh

_progressBar() {
  local pid="$1"
  if ps -p "$pid" &>/dev/null; then
    loop='▁▃▄▅▆▇█'
    while kill -0 "$pid" &>/dev/null; do
      printf "%b\r" "${loop:$((RANDOM%${#loop})):1}${loop:$((RANDOM%${#loop})):1}${loop:$((RANDOM%${#loop})):1}"
      sleep 0.1
    done
  fi
}

yourcommand &
_progressBar $!