Scripts/bin/alarm.sh

#!/usr/bin/env bash
set -euo pipefail # bash strict mode
clear
while true; do
    if [[ -z "${1:-}" ]]; then
        echo "Set alarm time in HH:MM AM/PM format"
        read -r ALARM_TIME
    else
        ALARM_TIME="$1"
    fi
    if [[ "$ALARM_TIME" =~ (1[0-2]|0?[1-9]):([0-5]?[0-9])(\s?[AP]M)? ]]; then
        echo "Alarm set to $ALARM_TIME"
        break
    else
        echo "Invalid time format"
        set --
        unset ALARM_TIME
    fi
done

run_at="$(date -d "$ALARM_TIME" +%s)"
current_time="$(date +%s)"
duration_to_sleep=$(( "$run_at"-"$current_time" ))

if [[ "$duration_to_sleep" -le "0" ]]; then
    echo "Can't set an alarm at past time"
    exit
fi

sleep "$duration_to_sleep"
notify-send "${2:-Alarm}" --icon=dialog-information
awk &>/dev/null '
BEGIN {
    k = 10
    while(k--) {
        i=j=500
        while (i--) print "a\0\0\0" | "aplay"
        while (j--) print "z\0\0" | "aplay"
    }
}
'
exit