Re: manpage of `dd`: multiplicative suffixes ambiguous

[Reuti]

> Am 18.08.2016 um 13:16 schrieb Pádraig Brady <address@hidden>:
> 
> On 18/08/16 11:27, Reuti wrote:
>> Hi,
>> 
>> looking in the man page of `dd` for multiplicative suffixes I understand 
>> that e.g. "K =1024". What I don't understand is the specification:
>> 
>> xM =M GB  =1000*1000*1000
>> 
>> between two commas. Is there a comma missing, or is the "xM =M" there by 
>> accident? It even reads this way in coreutils 8.25.
> 
> Yes a missing comma, which was not needed in --help output,

Thx, I see. I assume that originally in the --help output the second line 
mentioning G... was just not there, and "xM =M" was special (at that time, 
before multiplication was introduced).


> but due to wrapping is needed for the man page. Fixed in:
> http://git.sv.gnu.org/gitweb/?p=coreutils.git;a=commitdiff;h=v8.25-56-g3e71b06
> 
> NxM is calculated, so `dd count=10x12` processes 120 blocks.

I find this confusing as "M" refers to 12 here, not 1000 (I would never read 
the man page as "xM = times M" and replace "M" by an integer. As the 
multiplication is nowhere explained (I didn't know about it), maybe the "xM =M" 
should be left out and a phrase similar to the one in the BSD man page of `dd` 
added:

"Two or more numbers with or w/o multiplicative suffixes may be separated by an 
`x' to indicate a product."

(With the special case, that "k" can be used with both multiplicators in lower 
and upper case in the same way AFAICS.)

-- Reuti