Command line util to download a google calendar

download-calendar.rb

#!/usr/bin/env ruby

calendar_url = ARGV.shift

unless calendar_url
  puts "Usage: #{File.basename(__FILE__)} <calendar-url> [<download-directory>]"
  exit 1
end

download_directory = ARGV.shift
download_directory = File.dirname(__FILE__) unless download_directory and File.directory?(download_directory)

unless calendar_name = calendar_url[Regexp.new("/ical/(.*)/private-"), 1]
  puts "I can't determine the calendar's name from the URL (#{calendar_url})"
  exit 1
end

calendar_filename = [calendar_name, 'ics'].join('.')
calendar_path     = File.join(download_directory, calendar_filename)

puts "#{Time.now} - Downloading calendar to #{calendar_path}"
`curl -s "#{calendar_url}" > #{calendar_path}`