On Sun, Mar 09, 2003 at 11:48:50PM +1300, Jason wrote:
> [EMAIL PROTECTED] jason]$ dd if=/dev/cdrom of=91CD2.iso
> dd: reading `/dev/cdrom': Input/output error
> 1330624+0 records in
> 1330624+0 records out
Good.
> [EMAIL PROTECTED] jason]$ dd if=/dev/cdrom bs=2048 count= 332640 of=91CD2.iso
> dd: invalid number `'
'count=332640', not 'count= 332640'
> [EMAIL PROTECTED] jason]$ dd if=/dev/cdrom bs=2048 of=91CD2.iso
> dd: reading `/dev/cdrom': Input/output error
> 332656+0 records in
> 332656+0 records out
Same as the first.
> What am I doing wrong or are there errors on the CD's??
You're doing nothing wrong. because /dev/cdrom is a device, and you're not
specifying a length of data to get, the 'error' is simply the kernel telling
dd that 'nup, thats it from that device, sorry'. You can see that the number
reported (332656) the second time around, is quite close to the number you
tried to tell it to get.
I would have done it that way.
> Also, with dd, how do you specify where the of goes once copied. The
> info says it goes to stdout without a modifier. Where is stdout (I
> assume standard out but where the heck is that)?? What if want to send
> the copy to a specific directory?? Do I have to pipe it??
'of' *is* the modifier. as Martin said, try leaving it off, and you'll see
where stdout is.
> BTW, how do you check an MD5 sum from the CLI?? I assume it's file
> (exact path) | md5sum??
No. you need to give something to md5sum on stdin, (standard in), like you
are doing, but the file that you have there, will not show it's contents
like that.
you need: cat /dev/cdrom | md5sum
or, much easier: md5sum /dev/cdrom
> Then compare that to the sum MDK gives?? If that's right then I think
> Nick's CD's are bad:
> [EMAIL PROTECTED] jason]$ /dev/cdrom | md5sum
> bash: /dev/cdrom: Permission denied
> d41d8cd98f00b204e9800998ecf8427e -
> [EMAIL PROTECTED] jason]$
> PS, why does it say permission denied anyway??
Because /dev/cdrom is not an executable device. The md5sum you got, is just
that of 'nothing', since that's what it got on standard input.
I can regenerate that md5sum here, many ways:
[EMAIL PROTECTED]:~> md5sum
d41d8cd98f00b204e9800998ecf8427e -
[EMAIL PROTECTED]:~> echo -n | md5sum
d41d8cd98f00b204e9800998ecf8427e -
[EMAIL PROTECTED]:~> md5sum /dev/null
d41d8cd98f00b204e9800998ecf8427e /dev/null
etc etc.
(after pressing enter for the first one, I typed "^D" for an EOF, to give it
an empty 'file' on stdin.)
I'd do a bit of a tutorial on how to use the CLI, what stdout/stdin are, etc
etc, redirection, piping... whatever, but I have to get to work. if you want
me to, mail, and I'll try to tap something out later tonight.
Mike.
--
Mike Beattie <[EMAIL PROTECTED]> ZL4TXK, IRLP Node 6184
The first 90% of the code in a project takes 90% of the time.
The next 10% of the code will take another 90% of the time.
-- J. S. Labuschagne
