bash spinner function

spinner.sh

# Simple spinner function to show rotating stick
# while process is doing something useful
spinner() {
  local pid=$!
  local spin='-\|/'

  while kill -0 $pid 2>/dev/null
  do
    i=$(( (i+1) %4 ))
    printf "\r${spin:$i:1}"
    sleep .2
  done
  printf "\r"
}