#!/usr/bin/ruby
 
# Returns the EBS volume id of a device.  eg: /dev/sdj
 
if ARGV[0].nil?
  puts "You must specify the device.  eg: ec2-identify-volume /dev/sdj"
  exit 1
end
 
instance_id = `ec2-identify-instance`
device = ARGV[0].strip.downcase
volume_id = `ec2-describe-volumes | grep #{instance_id} | grep #{device}`.split("\t")[1]
print volume_id