Re: small usr.bin/find patch

wow. thanks a bunch for all the great info.

Matthew Seaman schrieb am 2009-06-24:
> Alexander Best wrote:
> > hmmm...but dd e.g. uses lowercase instead of upercase letters to
> > indicate
> > kilobyte, megabyte and so on. isn't there some unix/posix/whatever
> > standard
> > telling app developers what to use?

> Sure. The standard for scale-prefixes is defined by the Systeme
> Internationale as part of the definition of SI units:

>   http://www.npl.co.uk/reference/measurement-units/si-prefixes/

> Note that these are strictly powers-of-10^3 multipliers, and
> explicitly
> not the computing style powers-of-2^10 commonly used for file sizes
> or
> hard drive capacities, which should instead use the somewhat clunky
> Ki,
> Mi, Gi etc. forms:

>   http://physics.nist.gov/cuu/Units/binary.html

> These binary prefixes are mandated by the IEC and approved by the
> IEEE
> amongst others.

> Not that many people use the binary prefixes appropriately, relying
> on
> context to disambiguate 1 MB = 1024 KB = 1,048,576 Bytes etc.  Except
> that (confusingly) as a measure of network bandwidth 10 Mb/s always
> was
> 10,000,000 b/s and never 10,485,760 b/s; a fact that has caught me
> out
> more than a few times.

> Making find(1) / dd(1) / etc. operate pedantically correctly with
> these
> scale-factor symbols would cause a certain degree of pain for little
> practical gain.  Unless there was a broad consensus amongst all
> Unixoid
> OS providers, I can't see that change ever happening.

>         Cheers,

>         Matthew

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