ClamAV virus scan using INSTREAM

#!/usr/bin/ruby

require 'socket'

hostname = ARGV[0]
port = ARGV[1]
filename = ARGV[2]
begin
  socket = TCPSocket.new( hostname, port )
  socket.send( "zINSTREAM\0", 0)

  File.open(filename, 'r') do |f|
    while data = f.read(2048)
      socket.send( [data.length].pack('N'), 0)
      socket.send( data, 0)
    end
  end

  socket.send( [0].pack('N'), 0)
  socket.send( "", 0)
  
  response = socket.gets
  socket.close
  
  puts response
  
  if response.include?('FOUND')
    puts "A virus was found: #{response}"
  else
    puts "No virus was found"
  end
rescue Exception => e
  puts "Exception encountered, #{e.inspect}"
end