Retry something in Bash shell

retry.sh

retry() {
  local n=1
  local max=5
  local delay=15
  while true; do
    "$@" && break || {
      if [ $n -lt $max ]; then
        n=$((n+1))
        # No output on failure to allow redirecting output
        sleep $delay;
      else
        fail "The command has failed after $n attempts."
      fi
    }
  done
}