On Wed, 2005-01-19 at 11:43 -0500, Peter Jones wrote:
> On Sun, 2005-01-16 at 11:54 -0500, Alan Cox wrote:
> > On Sun, Jan 16, 2005 at 11:51:13AM -0500, Fulko Hew wrote:
> > > >Thats correct behaviour. The end of a CD is very low accuracy only.
> > >
> > > OK. But (in my nievity) doesn't that make it difficult to 'dup' CDs?
> > > ie. you couldn't do a: dd if=/dev/cdrom of=test.iso bs=2048
> >
> > Each copy will gradually get a bit longer unless you know the real .iso size
> > (which is easy to find).
>
> FWIW, we ship the program "isosize" to do this. So use -pad with
> cdrecord while burning, and then you can do this to make an iso from it:
>
> dd if=/dev/cdrom of=test.iso bs=4096 \
> count=$(($(isosize /dev/cdrom)/ 4096+1))
>
> And that shouldn't have the growth problem Alan has mentioned. Note
> that the "+1" is only really needed if the image doesn't end on a block
> boundary.
Of course, also note that I'm completely on crack about the block size,
and you should just do:
dd if=/dev/cdrom of=test.iso bs=2048 count=$(($(isosize /dev/cdrom)/2048))
as 2048 is the block size on a CD device.
Dunno what I was thinking.
--
Peter