Re: [9fans] Re: echo -n

["ron minnich" <rminnich@gmail.com>]

On 11/21/06, Fco. J. Ballesteros <nemo@lsub.org> wrote:
> :  I think Plan 9 got it completely right. Being able to push a 0-byte
> :  write through the kernel is mighty handy. I got quite annoyed with
> :  Unix at various points over the years as I watched "optimizations"
> :  gobble up my attempts to get a 0 byte write through the kernel.
>
> Do you remember why you wanted to push a 0-byte write?


it's usually io or networking.

many of the wacky networks I have dealt with have at times needed a
0-byte write; we got the effect via ioctl, since the kernel gobbled up
0-byte writes, the kernel of course knowing much better than you what
you were trying to do, e.g. Linux.

there is of course the need to write a blank punch card with a 0-byte
write, assuming you can find a card punch. And as david mentioned, in
a real case, tape marks.

but, seriously, it's the general issue that you need to tell something
(program, io device, network, whatever) that you don't have anything
to say, which is not the same as saying nothing.

ron