Simple Crontab Calculator

A command line program to calculate the time of the next occurence of a simplified crontab.

Crontabs for the purposes of this calculator use the syntax:

# ┌───────────── minute (0 - 59)
# │ ┌───────────── hour (0 - 23)
# * * script to execute

To use

You require a Ruby runtime to run the script. Mac OS has ruby installed by default. Linux users will have to install ruby for continuing.

Firstly, make the script executable. OSX

$ chmod +x ./cron_predictor.rb

The program takes two arguments. The first is a time in format HH:MM and the second argument is the path to file which holds your crontabs.

./cron_predictor.rb <HH:MM> <path/to/your/input/file>

ex. ./cron_predictor.rb 10:20 ./example_config

This project has an external dependency on RSpec so you will need to install this gem to run the specs. This assumes you have bundler installed.

OSX

$ bundle install
$ rspec spec/*spec.rb