Excited about the imminent availability of Big Sur but tired of checking the software update pane in System Preferences? Use this Ruby script to automate it and get a notification once it's available in your region.

bigsur_release_availability.rb

# NOTE: This script assumes that you system is otherwise updated, ie no other update is pending.
# You can add this script into crontab to run every 5 mins: */5 * * * *

require 'open3'

Open3.popen3("softwareupdate -l --force") do |_stdin, _stdout, stderr, _thread|
  unless stderr.read.match? /No new software available./
    exec(%q{osascript -e "display notification \"You have an update available.\""})
  end
end