From: rtilley <rtilley@...>
Date: 2006-03-19T23:48:49+09:00
Subject: Re: safe way to calc md5 on very large files

Robert Klemme wrote:
> io.read will return nil at EOF so your test for positive length is 
> basically obsolete.  Also, for reasons of error checking I'd place the 
> digest creation inside the block because then the digest is never 
> created if the file cannot be opened:
> 
> md5 = File.open(file, 'rb') do |io|
> dig = Digest::MD5.new
> while (buf = io.read(4096))
>   dig.update(buf)
> end
> dig
> end

Thank you Robert, Billy and others! Your suggestions have helped me to 
solve the problem.