Turns Your Laptop into an Alarm Clock While Putting It into Suspend

rtcalarm.rb

puts 'Make sure to run this with sudo-rights!' unless Process::UID.eid == 0
parser =  begin
            require 'chronic'
            lambda{|s| Chronic.parse s}
          rescue LoadError
            STDERR.puts 'Warning: Gem "Chronic" not found. Using Time.parse instead!'
            require 'time'
            lambda{|s| Time.parse s}
          end

begin
  at  = parser[ARGV.join(' ')]
  ads = (at - Time.now).to_i
rescue
  STDERR.puts $!
  puts "usage: #{__FILE__} <alarm time>"
  exit
end
ad  = "#{ads / 3600} hours #{ads % 3600 / 60} minutes"
print "Alarm will go off in #{ad}. OK? (Y/n) "
exit unless ['Y','y',''].include?(STDIN.gets.chomp) 
if ''==`pidof -x mplayer vlc mpg123 mpg321` # TODO: expand list of potential players!
  print "No music player seems to be running. Continue anyways? (Y/n) "
  exit unless ['Y','y',''].include?(STDIN.gets.chomp)
end
print "Setting RTC wakealarm ... "
puts `sh -c "echo 0 > /sys/class/rtc/rtc0/wakealarm" && sh -c "echo #{at.to_i} > /sys/class/rtc/rtc0/wakealarm"`
print "Setting xscreensaver-command -lock ... "
puts `xscreensaver-command -lock`
print "Going into suspend ... "
puts `pm-suspend`

I love this!