Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
From: "Dave Korn" <dave DOT korn AT artimi DOT com>
To: <cygwin AT cygwin DOT com>
Subject: Anyone know about interaction of 'dd' with memory cards?
Date: Thu, 22 Sep 2005 18:22:24 +0100
MIME-Version: 1.0
Content-Type: text/plain; 	charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Message-ID: <SERRANO1IfpT8vWyu9k000001df@SERRANO.CAM.ARTIMI.COM>


       Hi all,


  I've got a PC here with a memory card reader.  I've been using 'dd' like
so:

dd if=/dev/sdb bs=1024 count=32768 of=cf.img

to make image files from the contents of the disk.  What didn't work, OTOH,
was this:

dd if=/dev/sdb bs=1024 of=cf.img

  I was hoping that when I left the count argument out, dd would just read
the entire disk volume and stop when it reached the end.  But it didn't: the
file grew to several Gb before I Ctrl-C'd it.

  Now, dd is supposed to terminate the copy operation when it reaches EOF on
the input, and I doubt that is broken.  What I'm wondering is, I _expected_
that reading /dev/sdb would give an EOF when the entire drive's contents had
been read.  Was this a false assumption?  Is Cygwin _supposed_ to return an
EOF when you reach the end of a device volume, and it (or dd) is broken, or
has this never been implemented?

    cheers, 
      DaveK
-- 
Can't think of a witty .sigline today....


--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/