Simple bash script to calculate total seconds from hours, minutes and seconds

hours2seconds

#!/bin/bash

HOU=0
MIN=0
SEC=0

if [[ $# -ge 4 ]]
then
  echo "Please provide from 0 to a maximum of 3 arguments"
  exit 1

elif [[ $# == 0 ]]
then
  read -e -i $HOU -p "Please input hours   (default: 0) -> " HOU
  read -e -i $MIN -p "Please input minutes (default: 0) -> " MIN
  read -e -i $SEC -p "Please input seconds (default: 0) -> " SEC
  
elif [[ $# == 1 ]]
then
  echo "You provided only hours, defaulting minutes and seconds to 0."
  HOU=$1

elif [[ $# == 2 ]]
then
  echo "You provided only hours and minutes, defaulting seconds to 0."
  HOU=$1
  MIN=$2
 
elif [[ $# == 3 ]]
then
  HOU=$1
  MIN=$2
  SEC=$3
fi
  
echo "${HOU} hour(s) ${MIN} minute(s) ${SEC} second(s) are equal to:"
echo $((($HOU*3600) + ($MIN*60) + $SEC)) seconds