Anyone know about interaction of 'dd' with memory cards?

[Dave Korn]

       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....


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