the long (and rignt) way to get uptime with bash

#!/usr/bin/env bash
# tivasyk <tivasyk@gmail.com>

# Alternative (the right) way to get uptime
DUMP_STRING=$(cat /proc/uptime)
printf "Raw data: %s\n" "${DUMP_STRING}"
  TOTAL_SECS=${DUMP_STRING%%.*}
printf "Seconds:  %s\n" "${TOTAL_SECS}"

DAYS=$(( TOTAL_SECS / 86400 ))
HOURS=$(( (TOTAL_SECS - DAYS*86400) / 3600 ))
MINUTES=$(( (TOTAL_SECS - DAYS*86400 - HOURS*3600) / 60 ))
SECONDS=$(( TOTAL_SECS - DAYS*86400 - HOURS*3600 - MINUTES*60 ))

HOURS="0${HOURS}"; HOURS="${HOURS:(-2)}"
MINUTES="0${MINUTES}"; MINUTES="${MINUTES:(-2)}"
SECONDS="0${SECONDS}"; SECONDS="${SECONDS:(-2)}"

printf "Uptime: ${DAYS} days, ${HOURS}:${MINUTES}:${SECONDS}\n"