From: Bill Kelly <billk@...>
Date: 2009-11-29T03:12:48+09:00
Subject: Re: Ruby byte access to disk sectors like dd does


From: "Robert Klemme" <shortcutter@googlemail.com>
> On 11/28/2009 01:26 AM, Bill Kelly wrote:
>> 
>> :)  Here's a stab at it... (it does work properly if the last
>> read returns fewer than 16 bytes.)
> 
> What makes it stop working properly if the file size is a multiple of 16?

It works OK in either case, is what I was trying to say.  :)


>> ruby -e 'File.open("/dev/hdb", "rb") {|io| print(io.read(512))}' |
>>  ruby -e 'i=0; while(x=ARGF.read(16)); puts("%08x %-32s %s" % [i, x.unpack("H*"), x.tr("^\040-\176",".")]); i+=16; end'
> 
> Why do you separate this in two processes?  I've munged it a bit...

Same reason dd and hexdump are separate programs.

http://www.faqs.org/docs/artu/ch01s06.html


> ruby -e 'File.open("/dev/hdb", "rb"){|io|i=0;while(l=io.read(16));
> printf("%06x %-32s %s\n",i,l.unpack("H*").first,l.tr("^\040-\176","."));
> i+=l.bytesize end}'
> 
> 
> Cheers
> 
> robert


Regards,

Bill