Bash Pomodoro

pomodoro.sh

#!/bin/bash

# My shell pomodoro
WORK=25                                        # Minutes of work
PAUSE=5                                        # Minutes to a short pause
TIMES=1                                        # Repeat Pomodoro cycle TIMES times
usage() {                                      # Function: Print a help message.
  echo "Usage: $0 [ -t TIMES ] [ -w WORK ] [ -p PAUSE ]" 1>&2
}
exit_abnormal() {                              # Function: Exit with error.
  usage
  exit 1
}
while getopts ":t:w:p:" options; do            # Loop: Get the next option;
                                               # use silent error checking;
                                               # options t, w and p take arguments.
  case "${options}" in
    t)                                          # If the option is t,
    TIMES=${OPTARG}                             # Set $TIMES to specified value.
    re_isanum='^[0-9]+$'                        # Regex: match whole numbers only
    if ! [[ $TIMES =~ $re_isanum ]] ; then      # if $TIMES not a whole number:
    echo "Error: TIMES must be a positive, whole number."
    exit_abnormal
    exit 1
    elif [ $TIMES -eq "0" ]; then                # If it's zero:
    echo "Error: TIMES must be greater than zero."
    exit_abnormal                                # Exit abnormally.
    fi
    ;;                 
    w)                                    
      WORK=${OPTARG}         
      re_isanum='^[0-9]+$'
      if ! [[ $WORK =~ $re_isanum ]] ; then  
        echo "Error: WORK must be a positive, whole number."
        exit_abnormal
        exit 1
      elif [ $WORK -eq "0" ]; then
        echo "Error: WORK must be greater than zero."
        exit_abnormal
      fi
      ;;
    p)                                  
      PAUSE=${OPTARG}                      
      re_isanum='^[0-9]+$'                   
      if ! [[ $PAUSE =~ $re_isanum ]] ; then   
        echo "Error: PAUSE must be a positive, whole number."
        exit_abnormal
        exit 1
      elif [ $PAUSE -eq "0" ]; then          
        echo "Error: PAUSE must be greater than zero."
        exit_abnormal                  
      fi
      ;;
    :)                                         # If expected argument omitted:
      echo "Error: -${OPTARG} requires an argument."
      exit_abnormal                            # Exit abnormally.
      ;;
    *)                                         # If unknown (any other) option:
      exit_abnormal                            # Exit abnormally.
      ;;
  esac
done


echo Pomodoro repeating $TIMES times with $WORK working minutes and $PAUSE minutes of pause.

WORK=$(echo $(( WORK * 60 )))
PAUSE=$(echo $(( PAUSE * 60 )))

COUNT=1                                        # A counter.
while [ $COUNT -le $TIMES ]; do                # While counter is less than
                                               # or equal to $TIMES,
    notify-send "Your pomodoro session just started."
    sleep $WORK && notify-send "Your pomodoro session just ended. You may rest" && sleep $PAUSE && let COUNT+=1                                # then increment the counter.
done
notify-send "Your pomodoro cycle has ended"
exit 0                                         # Exit normally.