Counts down a long sleep

sleepcountdown.sh

#!/bin/bash

# Written by A.B. Carroll <[email protected]>
# Use as:
# sleepcountdown HOUR MIN SEC "Optional Prefix"
# Example:
# sleepcountdown 00 00 10 "Time until next run: "
# echo "Done with first countdown!"
# sleepcountdown 01 00 05 "Time until next run: "
# echo "Done with second countdown!"
sleepcountdown(){
    hr=$1
    min=$2
    sec=$3

    if [ -z "$4" ]
    then
        prefix=""
    else
        prefix="$4"
    fi

    while [ $hr -ge 0 ]; do
        while [ $min -ge 0 ]; do
            while [ $sec -ge 0 ]; do
                printf "%s%02d:%02d:%02d\33[0K" "${prefix}" "${hr}" "${min}" "${sec}"
                sec=$((sec-1))
                sleep 1
                printf "\r"
            done
        sec=59
        min=$((min-1))
        done
    min=59
    hr=$((hr-1))
    done
    printf "\n"
}