Simple 'spinner' for your scripts. Disclaimer: use at your own peril!

spinner.bash

#!/usr/bin/env bash
:
function spinner () {
  trap 'tput cnorm' RETURN SIGINT
  :
  sprite=('|' '/' '–' '\')
  SECONDS=0
  TIME_LIMIT=
  :
  local OPTIND opt d
  while getopts ":d:" opt; do
    case "${opt}" in
      d )
        TIME_LIMIT="${OPTARG}"
        ;;
      \?)
        printf 'Usage: %s [-d N]\n' "${FUNCNAME[0]}"
        printf 'Note: runs for N seconds.\n'
        return 0
        ;;
    esac
  done
  while :
  do
    tput civis
    for frame in "${sprite[@]}"
    do
      printf ' %s\r' $frame
      sleep 0.1
      tput dl 1
    done
    if [ ! -z ${TIME_LIMIT} ]; then
      [[ "$SECONDS" -ge "$TIME_LIMIT" ]] && return 0
    fi
  done
}
: