Re: daemontools tai64n is unbuffered, s6-tai64n is fully buffered

From: Buck Evan <buck_at_yelp.com>
Date: Tue, 20 Oct 2015 16:05:10 -0700

There's no loop around echo:

$ yes oh, hi! | pv -qL 10 | tai64n | s6-tai64nlocal
2015-10-20 09:47:02.681071500 oh, hi!
2015-10-20 09:47:03.493098500 oh, hi!
2015-10-20 09:47:04.304479500 oh, hi!
^C

 yes oh, hi! | pv -qL 10 | tai64n | tai64nlocal
2015-10-20 09:47:44.813611500 oh, hi!
2015-10-20 09:47:45.625627500 oh, hi!
2015-10-20 09:47:46.436990500 oh, hi!
2015-10-20 09:47:47.248335500 oh^C



This prints slowly enough that I can *see* that tai64nlocal is printing
each character separately, but s6-tainlocal is printing per-line.



On Tue, Oct 20, 2015 at 3:27 PM, Laurent Bercot <ska-skaware_at_skarnet.org>
wrote:

> On 20/10/2015 23:36, Buck Evan wrote:
>
>> Is it expected that it's line-buffered?
>>
>
> It's not line-buffered. It's optimally buffered, i.e. the buffer
> is flushed whenever it's full (obviously) or whenever the loop
> goes back to reading with a chance of blocking. When you test
> with a loop around echo, you send lines one by one, so the
> behaviour appears to be line buffering, but that's only an
> artifact of your test.
>
> --
> Laurent
>
>
Received on Tue Oct 20 2015 - 23:05:10 UTC