Ruby script to periodically match a web page against a regex

checksite.rb

require 'net/http'

$stdout.sync = true

if ARGV.include?("--help") || ![2,3,4].include?(ARGV.length)
  puts "ruby checksite.rb URL REGEX [NOTIFY_EMAIL] [INTERVAL_SECS]"
  exit!
end

uri = URI.parse(ARGV[0])
regex = Regexp.compile(ARGV[1])
interval = ARGV[2].to_i
email = ARGV[3]

loop do
  puts "Getting page from " + uri.to_s
  resp = Net::HTTP.get(uri)
  if resp =~ regex
    puts "Found a match!"
    if email
      puts "Emailing " + email
      `echo "Go get em tiger! #{uri.to_s}" | sendmail #{email}`
    else
      puts "No email, doing nothing"
    end
    break
  end
  puts "No match."
  if interval != 0
    puts "Sleeping for " + interval.to_s + " seconds"
    sleep(interval)
  else
    break
  end
end