From: Eric Hodel <drbrain@...7.net>
Date: 2008-07-02T06:43:37+09:00
Subject: Re: Problem with unpack

On Jul 1, 2008, at 13:32 PM, Rafael wrote:
> I'm trying to read a binary file and would want to find within the
> file a particular substring. I have done the following
>
> [...]

unpack is useful when you need to turn binary data into usable  
structure.  Just use a regular expression:

open 'testfile', 'rb' do |io|
   if io.read(512) =~ /\020/ then
     puts "The tag was found"
   else
     puts "The tag was not found"
   end
end