track-study.sh

#!/usr/bin/env bash

function check_arguments() {
  if [ -z "$1" ]
    then
      echo "No argument supplied"
      echo "  Usage  : ./track-study.sh <seconds to study>"
      echo "  Example: ./track-study.sh 10"
      exit
  fi
}

function count_down_time() {
  TOTAL_STUDY_TIME=$1

  for SECONDS_STUDIED in $(seq 1 $TOTAL_STUDY_TIME)
  do
    PERCENTAGE_DONE=$(($SECONDS_STUDIED*100/$TOTAL_STUDY_TIME))
    sleep 1
    echo -ne "$SECONDS_STUDIED seconds studied ($PERCENTAGE_DONE %) ...\r"
  done
}

function congratulate() {
  MESSAGE="Congratulations. You can have a break now."

  echo $MESSAGE
  # On MacOS there's program `say` which synthesizes speech to speakers
  if command -v say &> /dev/null
    then
    say $MESSAGE
  fi
}

# Main part of the program
check_arguments $1
count_down_time $1
congratulate