Is there a utility like cron, that schedules a job for later (but only once)?

I'm trying to design a program that sends a text when a certain (non-periodic) event occurs. Right now, I'd like a script that finds when this event occurs, and then schedules a (cron-like) job that will send a text just before that even occurs.

A more concrete example would look like this:

1. Script A runs and detects the next time of the event

2. Script A uses ??? to schedule Script B be to run at $time

3. At $time, ??? calls script B which sends the text.

The problem is, the event could be at a random time within 11 days, and it only happens once. Cron seems inappropriate for this -- I don't want this job to run more than once.

So I guess (in short), is there a utility that provides for the delayed execution of a script that's not periodic?

Solution 1:

Yup. It is called at.

Example:

echo 'logrotate -f /etc/logrotate.conf' | at '00:00'

Solution 2:

If you've got a script in a file already, at -f scriptname '00:00' is pretty useful also.