a countdown timer

countdown.sh

#!/bin/bash

IFS=:
set -- $*
param1=0
param2=0
param3=0
if [ ${3} > 0 ]; then
  param3=${3}
fi
if [ ${2} > 0 ]; then
  param2=${2}
fi
if [ ${1} > 0 ]; then
  param1=${1}
fi
secs=$(( (${param1} * 3600) + (${param2} * 60) + ${param3} ))
while [ $secs -gt 0 ]
do
  sleep 1 &
  printf "\r%02d:%02d:%02d" $((secs/3600)) $(( (secs/60)%60)) $((secs%60))
  secs=$(( $secs - 1 ))
  wait
done
printf "\r%02d:%02d:%02d" 0 0 0
paplay /usr/share/sounds/freedesktop/stereo/complete.oga
echo