#! /usr/bin/env ruby
#
# cdbiff - a mailbox flag for a CD-ROM drive
#
# Copyright (C) 2001 Satoru Takabayashi <satoru@namazu.org> 
#     All rights reserved.
#     This is free software with ABSOLUTELY NO WARRANTY.
#
# You can redistribute it and/or modify it under the terms of 
# the GNU General Public License version 2.
#

require 'getoptlong'
def print_usage
  print "\
Usage: cdbiff [OPTION]
  -f, --file=FILE		Monitor FILE [/var/mail/$USER]
  -c, --command=COMMAND		Execute COMMAND when mail arrives [eject]
  -i, --interval=SECONDS	Monitor at intervals of SECONDS [30]
  -h, --help             	Display this help and exit
"
end

def parse_options
  options = Hash.new

  parser = GetoptLong.new
  parser.set_options(['--file', '-f',		GetoptLong::REQUIRED_ARGUMENT],
		     ['--command', '-c',	GetoptLong::REQUIRED_ARGUMENT],
		     ['--inerval', '-i',	GetoptLong::REQUIRED_ARGUMENT],
		     ['--help', '-h',		GetoptLong::NO_ARGUMENT])
  parser.each_option {|name, arg|
    options[name.sub /^--/, ""] = arg
  }

  if options['help']
    print_usage
    exit 1
  end
  return options
end

def main
  options = parse_options

  filename = "/var/mail/#{ENV['USER']}"
  command = "eject"
  interval = 30

  filename = options['file'] if options['file']
  command = options['command'] if options['command']
  interval = options['interval'].to_i if options['interval']

  last = Time.now
  while true
    begin 
      current = File::mtime(filename)
    rescue
      next
    end
    if current > last
      system(command)
      last = current
    end
    sleep(interval)
  end
end

main