Shutdown remote server after 8 hours, with 1 hour warning.

shutdown_idle.sh

#!/bin/sh
# Adapted from https://gist.github.com/charles-cooper/a060b7225d010d93a37a62a7b4d1e2b4
# To email yourself, set up nullmailer with gmail app password (no spaces required), set up the cronjob with `sudo crontab -e`, then add the following:
# MAILTO="[email protected]"
# @hourly /home/chigozie/.local/bin/cron/shutdown_idle.sh
uptime=$(cat /proc/uptime | awk '{print $1}')
max_hours=7
if [ $(echo $uptime | cut -d '.' -f1) -ge $((60*60*$max_hours)) ]; then
#   Shutdown in 1 hour
    sudo shutdown -h +60
    echo "Save your work! This system will shut down in 1 hour! If you want to cancel this shutdown, use \`sudo shutdown -c\`"
else
    echo $(($(echo "$uptime" | cut -d '.' -f1)/60)) | awk '{print $1" minutes of uptime; after 7 hours, the system will schedule a shutdown with 1 hour warning."}'
fi