Re: dd conv=nocache

[Jim Meyering]

Pádraig Brady <address@hidden> wrote:
> Jim Meyering wrote:
>> Pádraig Brady <address@hidden> wrote:
>>> I was thinking it would be useful to
>>> add an option to dd to tell it to
>>> instruct the OS not to cache the data.
>>
>> I like the idea, even if it works only with very recent Linux
>> kernels.
>
> It's not that new. It's in since 2.5.60 according
> to the man page, and I verified the code is in 2.6.0
> Also it uses a posix interface, so I presume this is
> available elsewhere.

Note that I said "works", not exists :-)
Does it work consistently even for initial versions?

...
> I considered this, but thought you wouldn't need this granularity.
> But thinking more about it I think you're right.
>
> If we want to control input and output separately
> perhaps we should use flags. So we have:
> iflag=nocache and oflag=nocache

Of course!  Using that mechanism is the way to go.