balcony

A self-contained Clojure script that lets me know if I should water my balcony at night.

Credits

The idea to use exec came from Planck.

Installation

Make sure clj is installed. scp the script to a server or run from your own machine. Set the variables MAIL_USER, MAIL_PASS, MAIL_TO (comma seperated if you want multiple addresses) and WEATHER_API_KEY in e.g. .profile. Then hook the script up in cron:

crontab -e
30 19 * * * /usr/bin/env bash -c '. $HOME/.profile && $HOME/balcony.clj -m'

Options

• --develop or -d: development mode. Will start CIDER-nREPL.
• --mail or -m: send an email if today's temperature exceeded threshold.

What's with the weird first few lines?

The first few lines are relevant to bash, but not to the Clojure program. Still they have to be valid Clojure, because (using exec) clj executes the entire file. Also, it's convenient to be able to evaluate your entire file inside your editor. By making the Bash expressions readable by Clojure, you get no errors.