Re: dd - unsupported suffixes

[Henrik Holst]

Thank you for your answer Jim!

On Sat, Nov 01, 2008 at 08:41:07AM +0100, Jim Meyering wrote:
> Henrik Holst <address@hidden> wrote:
>> I think that the man page says that Z and Y suffix
>> should be supported (for BLOCK and BYTE fields)
>> but they are not in dd v6.10.
> 
> Thanks for the report.
> However, I don't see a problem.
> 
> I admit it might look like those suffixes are not supported:
> 
>     $ dd bs=1 seek=1Z of=x < /dev/null
>     dd: invalid number `1Z'
>     [Exit 1]
> 
> But that's just because 1Z and 1Y are larger than 2^64.
> You can use "0" instead of "1", to show that they are
> indeed accepted:
> 
>     $ dd bs=1 seek=0Y of=x < /dev/null
>     0+0 records in
>     0+0 records out
>     0 bytes (0 B) copied, 1.4038e-05 s, 0.0 kB/s
> 
> 
> If you still see a problem, please show the precise
> command you tried to run, and the output it produced.

I imagine to understand the technical reasons behind this limitation.
I will anyway show you the exact command I tired: 

dd if=/dev/zero of=/dev/null bs=1 count=1Y
dd: invalid number `1Y'

Here I interpreted "invalid number" as something that isn't a
mathematical integer rather than just being too big.

May I most humbly suggest a clarification in the manual?  "BLOCKS and
BYTES ... Z, Y. BLOCKS and BYTES are required to be smaller than 2^64."
(Given of course that this statement holds true on all platforms today
where dd is used.)

Friendly regards,
/Henrik Holst