Shell Programming and Scripting

 Any arguments
              remaining after the options are processed are treated as  values
              for the positional parameters and are assigned, in order, to $1,
              $2, ...  $n.

secs_to_sleep = 600

if ARGV.size == 0
  puts "I need the name of the directory."
  exit
end

dir = File.join( ARGV[0], "*" )
old = Dir[ dir ]

loop {
  sleep( secs_to_sleep )
  new = Dir[ dir ]
  
  print "Files deleted: " ; p old - new
  print "Files added: " ; p new - old
  puts

  old = new
}

1. read filenames and -sizes of all files in the directory to two arrays

in a while-loop do:
   1. sleep 10 mins
   2. read the contents of the content of the directory to two new arrays
      (filename and size), create a third array of the same size initalized with "0"s
   3. loop through the first array and throw out any entry you can find in the
      new array and which filesize hasn't changed, flag the file with a "1" in the 
      third array
   3a. if the filesize has changed print out "file changed" and drop it then after
       flagging it in the third array the same way
   4. print any arrayelement left in the old array as deleted
   5. print any arrayelement in the new array with a "0" in the third array as 
      "new file"
   6. drop the two old arrays and the third array with the flags and make the
      two new ones the old one.
done /* while-loop */