On 11/10/10 08:07, Pádraig Brady wrote: > BTW here are my notes on some possible changes in this area: > > `dd conv=sync` seems to do the wrong thing with pipes. > I.E. it pads out short reads. Why would one ever want that?
Nobody ever wants it but (as you note) it's required by the standard. > Should sync for pipes imply fullblock? I think that would be a good idea, but it should be done only if POSIXLY_CORRECT is not set, since it contradicts the standard. > Should sync for pipes without fullblock give a warning? I would say "no". If POSIXLY_CORRECT, the warning would arguably violate the standard. If not, there's no need for a warning. > Should specifying a count (and bs I suppose) without fullblock > when reading from pipes give a warning? No, for the same reason. Do you have time to implement this change? If not, I suppose I could look into it. It shouldn't be that hard. The hardest part would be the documentation. Regardless of whether we make such a change, we should document the issue, as this is a common problem.
