lae's notebook

A Simple Bash Alarm Clock

Someone on IRC linked to a script called DEADLINE, which got me to thinking, a simple alarm clock script should be easy to concoct in bash if that's what the end goal is. I did a quick Google search but didn't find any simple solutions - they were all excessive in some way. So, here I ended up creating a bash one-liner in a few minutes to see it in practice and confirm I wasn't crazy:

sleep $(( $(date --date="7 pm Feb 23, 2012" +%s) - $(date +%s))); echo "It's been a year since you touched this, and the sky is dark! Lalala."

I could easily expand this to request a simple date and play an audio file:

printf "What time are you setting this alarm for? "
read date
echo Okay! Will ring you on $(date --date="$date").
sleep $(( $(date --date="$date" +%s) - $(date +%s) ));
echo Wake up!
while true; do
  /usr/bin/mpg123 ~/alarm.mp3
  sleep 1

This can accept date inputs like "january 1 next year", "tomorrow", "23:00 today" and so forth. In fact, one could expand this script to test for valid dates, or replace the prompt with argument parsing for the same behaviour as "Deadline." I would also probably suggest adding nohup to the script, to relay its execution from the shell and into the background after the date has been inputted.

In fact, I may update this later when I have the time with a more robust (but still short and inexpensive) version.

There are a lot of things you can do with native UNIX utilities, and I'm not quite understanding why they aren't taken more advantage of.